X3D Model Documentation: FollowerPrototypeDeclarations.x3d

  1  <?xml version="1.0" encoding="UTF-8"?>
  2  <!DOCTYPE X3D PUBLIC "ISO//Web3D//DTD X3D 3.2//EN" "https://www.web3d.org/specifications/x3d-3.2.dtd">
  3  <X3D profile='Immersive' version='3.2 xmlns:xsd='http://www.w3.org/2001/XMLSchema-instance' xsd:noNamespaceSchemaLocation='https://www.web3d.org/specifications/x3d-3.2.xsd'>
  4       <head>
  5            <meta name='titlecontent='FollowerPrototypeDeclarations.x3d'/>
  6            <meta name='descriptioncontent='Original implementation pattern as prototype declarations for Follower (Chaser and Damper) nodes, useful for browser developers.'/>
  7            <meta name='creatorcontent='Herbert Stocker'/>
  8            <meta name='translatorcontent='Don Brutzman'/>
  9            <meta name='createdcontent='18 April 2006'/>
 10            <meta name='translatedcontent='2 December 2011'/>
 11            <meta name='modifiedcontent='20 October 2019'/>
 12            <meta name='referencecontent='FollowerExternalPrototypeDeclarations.x3d'/>
 13            <meta name='referencecontent='originals/Chasers.wrl'/>
 14            <meta name='referencecontent='originals/Dampers.wrl'/>
 15            <meta name='referencecontent='Stocker_06_Followers.pdf'/>
 16            <meta name='referencecontent='http://www.hersto.com/Publications/Followers'/>
 17            <meta name='requirescontent='X3D version 3.0, 3.1'/>
 18            <meta name='subjectcontent='X3D Follower Chaser Damper'/>
 19            <meta name=' warning content=' under development '/>
 20            <meta name=' TODO content=' Rename and test these prototypes to match final names in X3D Specification Followers Component '/>
 21            <meta name=' TODO content=' Ensure full coverage of follower nodes in order to provide backwards compatibility with X3D v3.0 and v3.1. '/>
 22            <meta name=' TODO content=' Xj3D Player Bugzilla Issue http://bugzilla.xj3d.org/show_bug.cgi?id=639 '/>
 23            <meta name='referencecontent='https://www.web3d.org/x3d/specifications/ISO-IEC-19775-1.2-X3D-AbstractSpecification/Part01/components/followers.html'/>
 24            <meta name='referencecontent='https://www.web3d.org/x3d/content/examples/X3dSceneAuthoringHints.html'/>
 25            <meta name='identifiercontent='https://www.web3d.org/x3d/content/examples/Basic/Followers/FollowerPrototypeDeclarations.x3d'/>
 26            <meta name='generatorcontent='Vrml97ToX3dNist, http://ovrt.nist.gov/v2_x3d.html'/>
 27            <meta name='generatorcontent='X3D-Edit 3.3, https://savage.nps.edu/X3D-Edit'/>
 28            <meta name='licensecontent='../../license.html'/>
 29       </head>
<!--

<!--
Event Graph ROUTE Table shows event connections.
-->

<!-- to top Index for DEF nodes: EFFS, LastNode, ScreenPositionDamper_OrientationChaser, ScreenPositionDamper_PlacementChaser, ScreenPositionDamper_Position2fChaser, ScreenPositionDamper_PositionChaser, Timer_PositionDamper, Tmer_OrientationChaser, Tmer_PlacementChaser, Tmer_Position2fChaser, Tmer_PositionChaser, Worker

Index for ProtoDeclare definitions: EFFS, OrientationChaser, PlacementChaser, Position2fChaser, PositionChaser, PositionDamper
-->
 30       <Scene>
 31            <WorldInfo info=' "The ExternProto nodes found in this file implement principles described in the paper" "Linear Filters - Animating Objects in a Flexible and Pleasing Way" "They have been proposed and added to the X3D standard in 2006." "Webpage: "http://www.hersto.net/Followers" "" "Please use the code in this file in any content or application you like" "or modify it in any way." "" "The code here works, however things like detecting when a transition has ended" "and when the node can stop calculating and updating the output or secondary fields" "like set_value or initial_destination are not yet implemented." "Nevertheless, set_destination and value_changed do work." ' title='Damper nodes'/>
 32            <ProtoDeclare name='PositionChaser'>
 33                 <ProtoInterface>
 34                      <field name='value_changedtype='SFVec3faccessType='outputOnly'/>
 35                      <field name='set_valuetype='SFVec3faccessType='inputOnly'/>
 36                      <field name='creditstype='MFStringvalue=' "Initial idea and copyright by Herbert Stocker "http://www.hersto.net"' accessType='initializeOnly'/>
 37                      <field name='isActivetype='SFBoolaccessType='outputOnly'/>
 38                      <field name='set_destinationtype='SFVec3faccessType='inputOnly'/>
 39                      <field name='durationtype='SFTimevalue='1.0accessType='initializeOnly'/>
 40                      <field name='initial_destinationtype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
 41                      <field name='initial_valuetype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
 42                 </ProtoInterface>
 43                 <ProtoBody>
 44 
                    <!-- ROUTE information for ScreenPositionDamper_PositionChaser node:  [from Tmer_PositionChaser.time to Tick ] -->
                    <Script DEF='ScreenPositionDamper_PositionChaser'>
 45                           <field name='Ticktype='SFTimeaccessType='inputOnly'/>
 46                           <field name='set_valuetype='SFVec3faccessType='inputOnly'/>
 47                           <field name='durationtype='SFTimeaccessType='initializeOnly'/>
 48                           <field name='Buffertype='MFVec3faccessType='initializeOnly'/>
 49                           <field name='bInitializedtype='SFBoolvalue='falseaccessType='initializeOnly'/>
 50                           <field name='BufferEndTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
 51                           <field name='cNumSupportstype='SFInt32value='10accessType='initializeOnly'/>
 52                           <field name='set_destinationtype='SFVec3faccessType='inputOnly'/>
 53                           <field name='value_changedtype='SFVec3faccessType='outputOnly'/>
 54                           <field name='cStepTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
 55                           <field name='previousValuetype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
 56                           <field name='initial_destinationtype='SFVec3faccessType='initializeOnly'/>
 57                           <field name='destinationtype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
 58                           <field name='isActivetype='SFBoolaccessType='outputOnly'/>
 59                           <field name='initial_valuetype='SFVec3faccessType='initializeOnly'/>
 60                           <IS>
 61                                <connect nodeField='set_valueprotoField='set_value'/>
 62                                <connect nodeField='durationprotoField='duration'/>
 63                                <connect nodeField='set_destinationprotoField='set_destination'/>
 64                                <connect nodeField='value_changedprotoField='value_changed'/>
 65                                <connect nodeField='initial_destinationprotoField='initial_destination'/>
 66                                <connect nodeField='isActiveprotoField='isActive'/>
 67                                <connect nodeField='initial_valueprotoField='initial_value'/>
 68                           </IS>
  <![CDATA[
          
ecmascript:

function initialize()
{
    CheckInit();
}

function CheckInit()
{
    if(!bInitialized)
    {
        bInitialized= true;  // Init() may call other functions that call CheckInit(). In that case it's better the flag is already set, otherwise an endless loop would occur.
        Init();
    }
}

function Init()
{
    destination= initial_destination;

    Buffer.length= cNumSupports;

    Buffer[0]= initial_destination;
    for(var C= 1; C<Buffer.length; C++ )
        Buffer[C]= initial_value;

    previousValue= initial_value;

    cStepTime= duration / cNumSupports;
}

function set_destination(Dest, Now)
{
    CheckInit();

    destination= Dest;
    // Somehow we assign to Buffer[-1] and wait untill this gets shifted into the real buffer.
    // Would we assign to Buffer[0] instead, we'd have no delay, but this would create a jump in the
    // output because Buffer[0] is associated with a value in the past.

    UpdateBuffer(Now);
}

function Tick(Now)
{
    CheckInit();

    if(!BufferEndTime)
    {
        BufferEndTime= Now; // first event we received, so we are in the initialization phase.

        value_changed= initial_value;
        return;
    }

    var Frac= UpdateBuffer(Now);
    // Frac is a value in   0 <= Frac < 1.

    // Now we can calculate the output.
    // This means we calculate the delta between each entry in Buffer and its previous
    // entries, calculate the step response of each such step and add it to form the output.

    // The oldest vaule Buffer[Buffer.length - 1] needs some extra thought, because it has
    // no previous value. More exactly, we haven't stored a previous value anymore.
    // However, the step response of that missing previous value has already reached its
    // destination, so we can - would we have that previous value - use this as a start point
    // for adding the step responses.
    // Actually UpdateBuffer(.) maintains this value in

    var Output= previousValue;

    var DeltaIn= Buffer[Buffer.length - 1].subtract(previousValue);

    var DeltaOut= DeltaIn.multiply(StepResponse((Buffer.length - 1 + Frac) * cStepTime));

    Output= Output.add(DeltaOut);

    for(var C= Buffer.length - 2; C>=0; C-- )
    {
        var DeltaIn= Buffer[C].subtract(Buffer[C + 1]);

        var DeltaOut= DeltaIn.multiply(StepResponse((C + Frac) * cStepTime));

        Output= Output.add(DeltaOut);
    }
    if(Output != value_changed)
        value_changed= Output;
}

function UpdateBuffer(Now)
{
    var Frac= (Now - BufferEndTime) / cStepTime;
    // is normally < 1. When it has grown to be larger than 1, we have to shift the array because the step response
    // of the oldest entry has already reached its destination, and it's time for a newer entry.
    // has already reached it
    // In the case of a very low frame rate, or a very short cStepTime we may need to shift by more than one entry.

    if(Frac >= 1)
    {
        var NumToShift= Math.floor(Frac);
        Frac-= NumToShift;

        if(NumToShift < Buffer.length)
        {   // normal case.

            previousValue= Buffer[Buffer.length - NumToShift];

            for(var C= Buffer.length - 1; C>=NumToShift; C-- )
                Buffer[C]= Buffer[C - NumToShift];

            for(var C= 0; C<NumToShift; C++ )
            {
                // Hmm, we have a destination value, but don't know how it has
                // reached the current state.
                // Therefore we do a linear interpolation from the latest value in the buffer to destination.

                var Alpha= C / NumToShift;

                Buffer[C]= Buffer[NumToShift].multiply(Alpha).add(destination.multiply((1 - Alpha)));
            }
        }else
        {
            // degenerated case:
            //
            // We have a _VERY_ low frame rate...
            // we can only guess how we should fill the array.
            // Maybe we could write part of a linear interpolation
            // from Buffer[0] to destination, that goes from BufferEndTime to Now
            // (possibly only the end of the interpolation is to be written),
            // but if we rech here we are in a very degenerate case...
            // Thus we just write destination to the buffer.

            previousValue= NumToShift == Buffer.length? Buffer[0] : destination;

            for(var C= 0; C<Buffer.length; C++ )
                Buffer[C]= destination;
        }

        BufferEndTime+= NumToShift * cStepTime;
    }
    return Frac;
}

function StepResponse(t)
{
    if(t < 0)
        return 0;

    if(t > duration)
        return 1;

    // When optimizing for speed, the above two if(.) cases can be omitted,
    // as this funciton will not be called for values outside of 0..duration.

    return StepResponseCore(t / duration);
}

// This function defines the shape of how the output responds to the input.
// It must accept values for T in the range 0 <= T <= 1.
// In order to create a smooth animation, it should return 0 for T == 0,
// 1 for T == 1 and be sufficient smooth in the range 0 <= T <= 1.

// It should be optimized for speed, in order for high performance. It's
// executed Buffer.length + 1 times each simulation tick.

function StepResponseCore(T)
{
    return .5 - .5 * Math.cos(T * Math.PI);
}

// The following functions are not used. They provide other responses (for fun).
function StepResponseCoreF(T)
{
    var cTau= .3;
    var cFrequency= 2.5;
    return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI));
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI))* (.5 + .5 * Math.cos(T * Math.PI));
}


function StepResponseCoreE(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin(Math.sqrt(1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}


function StepResponseCoreD(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin((1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}

function StepResponseCoreC(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);

    return A * .8 + B * .2;
}

function StepResponseCoreB(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    return A * .8 + B * .2;
}
function StepResponseCoreA(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    var Alpha= .2 * T;
    return A * (1 - Alpha) + B * Alpha;
}

        
]]>
 70                      </Script>
 71 
                    <!-- ROUTE information for Tmer_PositionChaser node:  [from time to ScreenPositionDamper_PositionChaser.Tick ] -->
                    <TimeSensor DEF='Tmer_PositionChaserloop='true'/>
 72                      < ROUTE  fromNode='Tmer_PositionChaser' fromField='time' toNode='ScreenPositionDamper_PositionChaser' toField='Tick'/>
 73                 </ProtoBody>
 74            </ProtoDeclare>
 75            <ProtoDeclare name='OrientationChaser'>
 76                 <ProtoInterface>
 77                      <field name='value_changedtype='SFRotationaccessType='outputOnly'/>
 78                      <field name='set_valuetype='SFRotationaccessType='inputOnly'/>
 79                      <field name='creditstype='MFStringvalue=' "Initial idea and copyright by Herbert Stocker "http://www.hersto.net/"' accessType='initializeOnly'/>
 80                      <field name='isActivetype='SFBoolaccessType='outputOnly'/>
 81                      <field name='set_destinationtype='SFRotationaccessType='inputOnly'/>
 82                      <field name='durationtype='SFTimevalue='1.0accessType='initializeOnly'/>
 83                      <field name='initial_destinationtype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
 84                      <field name='initial_valuetype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
 85                 </ProtoInterface>
 86                 <ProtoBody>
 87 
                    <!-- ROUTE information for ScreenPositionDamper_OrientationChaser node:  [from Tmer_OrientationChaser.time to Tick ] -->
                    <Script DEF='ScreenPositionDamper_OrientationChaser'>
 88                           <field name='Ticktype='SFTimeaccessType='inputOnly'/>
 89                           <field name='set_valuetype='SFRotationaccessType='inputOnly'/>
 90                           <field name='durationtype='SFTimeaccessType='initializeOnly'/>
 91                           <field name='Buffertype='MFRotationaccessType='initializeOnly'/>
 92                           <field name='bInitializedtype='SFBoolvalue='falseaccessType='initializeOnly'/>
 93                           <field name='BufferEndTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
 94                           <field name='cNumSupportstype='SFInt32value='10accessType='initializeOnly'/>
 95                           <field name='set_destinationtype='SFRotationaccessType='inputOnly'/>
 96                           <field name='value_changedtype='SFRotationaccessType='outputOnly'/>
 97                           <field name='cStepTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
 98                           <field name='previousValuetype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
 99                           <field name='initial_destinationtype='SFRotationaccessType='initializeOnly'/>
100                           <field name='destinationtype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
101                           <field name='isActivetype='SFBoolaccessType='outputOnly'/>
102                           <field name='initial_valuetype='SFRotationaccessType='initializeOnly'/>
103                           <IS>
104                                <connect nodeField='set_valueprotoField='set_value'/>
105                                <connect nodeField='durationprotoField='duration'/>
106                                <connect nodeField='set_destinationprotoField='set_destination'/>
107                                <connect nodeField='value_changedprotoField='value_changed'/>
108                                <connect nodeField='initial_destinationprotoField='initial_destination'/>
109                                <connect nodeField='isActiveprotoField='isActive'/>
110                                <connect nodeField='initial_valueprotoField='initial_value'/>
111                           </IS>
  <![CDATA[
          
ecmascript:

function initialize()
{
    CheckInit();
}

function CheckInit()
{
    if(!bInitialized)
    {
        bInitialized= true;  // Init() may call other functions that call CheckInit(). In that case it's better the flag is already set, otherwise an endless loop would occur.
        Init();
    }
}

function Init()
{
    destination= initial_destination;

    Buffer.length= cNumSupports;

    Buffer[0]= initial_destination;
    for(var C= 1; C<Buffer.length; C++ )
        Buffer[C]= initial_value;

    previousValue= initial_value;

    cStepTime= duration / cNumSupports;
}

function set_destination(Dest, Now)
{
    CheckInit();

    destination= Dest;
    // Somehow we assign to Buffer[-1] and wait untill this gets shifted into the real buffer.
    // Would we assign to Buffer[0] instead, we'd have no delay, but this would create a jump in the
    // output because Buffer[0] is associated with a value in the past.

    UpdateBuffer(Now);
}

function Tick(Now)
{
    CheckInit();

    if(!BufferEndTime)
    {
        BufferEndTime= Now; // first event we received, so we are in the initialization phase.

        value_changed= initial_value;
        return;
    }

    var Frac= UpdateBuffer(Now);
    // Frac is a value in   0 <= Frac < 1.

    // Now we can calculate the output.
    // This means we calculate the delta between each entry in Buffer and its previous
    // entries, calculate the step response of each such step and add it to form the output.

    // The oldest vaule Buffer[Buffer.length - 1] needs some extra thought, because it has
    // no previous value. More exactly, we haven't stored a previous value anymore.
    // However, the step response of that missing previous value has already reached its
    // destination, so we can - would we have that previous value - use this as a start point
    // for adding the step responses.
    // Actually UpdateBuffer(.) maintains this value in

    var Output= previousValue;

    var DeltaIn= previousValue.inverse().multiply(Buffer[Buffer.length - 1]);

    Output= Output.slerp(Output.multiply(DeltaIn), StepResponse((Buffer.length - 1 + Frac) * cStepTime));

    for(var C= Buffer.length - 2; C>=0; C-- )
    {
        var DeltaIn= Buffer[C + 1].inverse().multiply(Buffer[C]);

        Output= Output.slerp(Output.multiply(DeltaIn), StepResponse((C + Frac) * cStepTime));
    }


    if(Output != value_changed)
        value_changed= Output;
}

function UpdateBuffer(Now)
{
    var Frac= (Now - BufferEndTime) / cStepTime;
    // is normally < 1. When it has grown to be larger than 1, we have to shift the array because the step response
    // of the oldest entry has already reached its destination, and it's time for a newer entry.
    // has already reached it
    // In the case of a very low frame rate, or a very short cStepTime we may need to shift by more than one entry.

    if(Frac >= 1)
    {
        var NumToShift= Math.floor(Frac);
        Frac-= NumToShift;

        if(NumToShift < Buffer.length)
        {   // normal case.

            previousValue= Buffer[Buffer.length - NumToShift];

            for(var C= Buffer.length - 1; C>=NumToShift; C-- )
                Buffer[C]= Buffer[C - NumToShift];

            for(var C= 0; C<NumToShift; C++ )
            {
                // Hmm, we have a destination value, but don't know how it has
                // reached the current state.
                // Therefore we do a linear interpolation from the latest value in the buffer to destination.

                Buffer[C]= destination.slerp(Buffer[NumToShift], C / NumToShift);
            }
        }else
        {
            // degenerated case:
            //
            // We have a _VERY_ low frame rate...
            // we can only guess how we should fill the array.
            // Maybe we could write part of a linear interpolation
            // from Buffer[0] to destination, that goes from BufferEndTime to Now
            // (possibly only the end of the interpolation is to be written),
            // but if we rech here we are in a very degenerate case...
            // Thus we just write destination to the buffer.

            previousValue= NumToShift == Buffer.length? Buffer[0] : destination;

            for(var C= 0; C<Buffer.length; C++ )
                Buffer[C]= destination;
        }
        BufferEndTime+= NumToShift * cStepTime;
    }

return Frac;
}

function StepResponse(t)
{
    if(t < 0)
        return 0;

    if(t > duration)
        return 1;

    // When optimizing for speed, the above two if(.) cases can be omitted,
    // as this funciton will not be called for values outside of 0..duration.

     return StepResponseCore(t / duration);
}

// This function defines the shape of how the output responds to the input.
// It must accept values for T in the range 0 <= T <= 1.
// In order to create a smooth animation, it should return 0 for T == 0,
// 1 for T == 1 and be sufficient smooth in the range 0 <= T <= 1.

// It should be optimized for speed, in order for high performance. It's
// executed Buffer.length + 1 times each simulation tick.

function StepResponseCore(T)
{
    return .5 - .5 * Math.cos(T * Math.PI);
}

// The following functions are not used. They provide other responses (for fun).

function StepResponseCoreG(T)
{
    var cTau= .3;
    var cFrequency= 5;
    return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI));
}

function StepResponseCoreF(T)
{
    var cTau= .3;
    var cFrequency= 2.5;
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI));
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI))* (.5 + .5 * Math.cos(T * Math.PI));
}

function StepResponseCoreE(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin(Math.sqrt(1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}

function StepResponseCoreD(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin((1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}

function StepResponseCoreC(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);

    return A * .8 + B * .2;
}

function StepResponseCoreB(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    return A * .8 + B * .2;
}

function StepResponseCoreA(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);
    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);
    var Alpha= .2 * T;
    return A * (1 - Alpha) + B * Alpha;
}

        
]]>
113                      </Script>
114 
                    <!-- ROUTE information for Tmer_OrientationChaser node:  [from time to ScreenPositionDamper_OrientationChaser.Tick ] -->
                    <TimeSensor DEF='Tmer_OrientationChaserloop='true'/>
115                      < ROUTE  fromNode='Tmer_OrientationChaser' fromField='time' toNode='ScreenPositionDamper_OrientationChaser' toField='Tick'/>
116                 </ProtoBody>
117            </ProtoDeclare>
118            <ProtoDeclare name='Position2fChaser'>
119                 <ProtoInterface>
120                      <field name='value_changedtype='SFVec2faccessType='outputOnly'/>
121                      <field name='set_valuetype='SFVec2faccessType='inputOnly'/>
122                      <field name='creditstype='MFStringvalue=' "Initial idea and copyright by Herbert Stocker "http://www.hersto.net/"' accessType='initializeOnly'/>
123                      <field name='isActivetype='SFBoolaccessType='outputOnly'/>
124                      <field name='set_destinationtype='SFVec2faccessType='inputOnly'/>
125                      <field name='durationtype='SFTimevalue='1.0accessType='initializeOnly'/>
126                      <field name='initial_destinationtype='SFVec2fvalue='0.0 0.0accessType='initializeOnly'/>
127                      <field name='initial_valuetype='SFVec2fvalue='0.0 0.0accessType='initializeOnly'/>
128                 </ProtoInterface>
129                 <ProtoBody>
130 
                    <!-- ROUTE information for ScreenPositionDamper_Position2fChaser node:  [from Tmer_Position2fChaser.time to Tick ] -->
                    <Script DEF='ScreenPositionDamper_Position2fChaser'>
131                           <field name='Ticktype='SFTimeaccessType='inputOnly'/>
132                           <field name='set_valuetype='SFVec2faccessType='inputOnly'/>
133                           <field name='durationtype='SFTimeaccessType='initializeOnly'/>
134                           <field name='Buffertype='MFVec2faccessType='initializeOnly'/>
135                           <field name='bInitializedtype='SFBoolvalue='falseaccessType='initializeOnly'/>
136                           <field name='BufferEndTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
137                           <field name='cNumSupportstype='SFInt32value='10accessType='initializeOnly'/>
138                           <field name='set_destinationtype='SFVec2faccessType='inputOnly'/>
139                           <field name='value_changedtype='SFVec2faccessType='outputOnly'/>
140                           <field name='cStepTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
141                           <field name='previousValuetype='SFVec2fvalue='0.0 0.0accessType='initializeOnly'/>
142                           <field name='initial_destinationtype='SFVec2faccessType='initializeOnly'/>
143                           <field name='destinationtype='SFVec2fvalue='0.0 0.0accessType='initializeOnly'/>
144                           <field name='isActivetype='SFBoolaccessType='outputOnly'/>
145                           <field name='initial_valuetype='SFVec2faccessType='initializeOnly'/>
146                           <IS>
147                                <connect nodeField='set_valueprotoField='set_value'/>
148                                <connect nodeField='durationprotoField='duration'/>
149                                <connect nodeField='set_destinationprotoField='set_destination'/>
150                                <connect nodeField='value_changedprotoField='value_changed'/>
151                                <connect nodeField='initial_destinationprotoField='initial_destination'/>
152                                <connect nodeField='isActiveprotoField='isActive'/>
153                                <connect nodeField='initial_valueprotoField='initial_value'/>
154                           </IS>
  <![CDATA[
          
ecmascript:

function initialize()
{
    CheckInit();
}

function CheckInit()
{
    if(!bInitialized)
    {
        bInitialized= true;  // Init() may call other functions that call CheckInit(). In that case it's better the flag is already set, otherwise an endless loop would occur.
        Init();
    }
}

function Init()
{
    destination= initial_destination;

    Buffer.length= cNumSupports;

    Buffer[0]= initial_destination;
    for(var C= 1; C<Buffer.length; C++ )
        Buffer[C]= initial_value;

    previousValue= initial_value;

    cStepTime= duration / cNumSupports;
}

function set_destination(Dest, Now)
{
    CheckInit();

    destination= Dest;
    // Somehow we assign to Buffer[-1] and wait untill this gets shifted into the real buffer.
    // Would we assign to Buffer[0] instead, we'd have no delay, but this would create a jump in the
    // output because Buffer[0] is associated with a value in the past.

    UpdateBuffer(Now);
}

function Tick(Now)
{
    CheckInit();

    if(!BufferEndTime)
    {
        BufferEndTime= Now; // first event we received, so we are in the initialization phase.

        value_changed= initial_value;
        return;
    }

    var Frac= UpdateBuffer(Now);
    // Frac is a value in   0 <= Frac < 1.

    // Now we can calculate the output.
    // This means we calculate the delta between each entry in Buffer and its previous
    // entries, calculate the step response of each such step and add it to form the output.

    // The oldest vaule Buffer[Buffer.length - 1] needs some extra thought, because it has
    // no previous value. More exactly, we haven't stored a previous value anymore.
    // However, the step response of that missing previous value has already reached its
    // destination, so we can - would we have that previous value - use this as a start point
    // for adding the step responses.
    // Actually UpdateBuffer(.) maintains this value in

    var Output= previousValue;

    var DeltaIn= Buffer[Buffer.length - 1].subtract(previousValue);

    var DeltaOut= DeltaIn.multiply(StepResponse((Buffer.length - 1 + Frac) * cStepTime));

    Output= Output.add(DeltaOut);

    for(var C= Buffer.length - 2; C>=0; C-- )
    {
        var DeltaIn= Buffer[C].subtract(Buffer[C + 1]);

        var DeltaOut= DeltaIn.multiply(StepResponse((C + Frac) * cStepTime));

        Output= Output.add(DeltaOut);
    }


    if(Output != value_changed)
        value_changed= Output;
}

function UpdateBuffer(Now)
{
    var Frac= (Now - BufferEndTime) / cStepTime;
    // is normally < 1. When it has grown to be larger than 1, we have to shift the array because the step response
    // of the oldest entry has already reached its destination, and it's time for a newer entry.
    // has already reached it
    // In the case of a very low frame rate, or a very short cStepTime we may need to shift by more than one entry.

    if(Frac >= 1)
    {
        var NumToShift= Math.floor(Frac);
        Frac-= NumToShift;

        if(NumToShift < Buffer.length)
        {   // normal case.

            previousValue= Buffer[Buffer.length - NumToShift];

            for(var C= Buffer.length - 1; C>=NumToShift; C-- )
                Buffer[C]= Buffer[C - NumToShift];

            for(var C= 0; C<NumToShift; C++ )
            {
                // Hmm, we have a destination value, but don't know how it has
                // reached the current state.
                // Therefore we do a linear interpolation from the latest value in the buffer to destination.

                var Alpha= C / NumToShift;

                Buffer[C]= Buffer[NumToShift].multiply(Alpha).add(destination.multiply((1 - Alpha)));
            }
        }else
        {
            // degenerated case:
            //
            // We have a _VERY_ low frame rate...
            // we can only guess how we should fill the array.
            // Maybe we could write part of a linear interpolation
            // from Buffer[0] to destination, that goes from BufferEndTime to Now
            // (possibly only the end of the interpolation is to be written),
            // but if we rech here we are in a very degenerate case...
            // Thus we just write destination to the buffer.

            previousValue= NumToShift == Buffer.length? Buffer[0] : destination;

            for(var C= 0; C<Buffer.length; C++ )
                Buffer[C]= destination;
        }

        BufferEndTime+= NumToShift * cStepTime;
    }

return Frac;
}



function StepResponse(t)
{
    if(t < 0)
return 0;

    if(t > duration)
return 1;

    // When optimizing for speed, the above two if(.) cases can be omitted,
    // as this funciton will not be called for values outside of 0..duration.

return StepResponseCore(t / duration);
}


// This function defines the shape of how the output responds to the input.
// It must accept values for T in the range 0 <= T <= 1.
// In order to create a smooth animation, it should return 0 for T == 0,
// 1 for T == 1 and be sufficient smooth in the range 0 <= T <= 1.

// It should be optimized for speed, in order for high performance. It's
// executed Buffer.length + 1 times each simulation tick.
function StepResponseCore(T)
{
return .5 - .5 * Math.cos(T * Math.PI);
}


// The following functions are not used. They provide other responses (for fun).
function StepResponseCoreF(T)
{
    var cTau= .3;
    var cFrequency= 2.5;
return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI));
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI))* (.5 + .5 * Math.cos(T * Math.PI));
}

function StepResponseCoreE(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

  var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin(Math.sqrt(1 - T) * Math.PI/2);

return A * .8 + B * .2;
}

function StepResponseCoreD(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

  var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin((1 - T) * Math.PI/2);

return A * .8 + B * .2;
}

function StepResponseCoreC(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

  var cTau= .3;
  var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);

return A * .8 + B * .2;
}

function StepResponseCoreB(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

  var cTau= .3;
  var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

return A * .8 + B * .2;
}

function StepResponseCoreA(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

  var cTau= .3;
  var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    var Alpha= .2 * T;
return A * (1 - Alpha) + B * Alpha;
}

        
]]>
156                      </Script>
157 
                    <!-- ROUTE information for Tmer_Position2fChaser node:  [from time to ScreenPositionDamper_Position2fChaser.Tick ] -->
                    <TimeSensor DEF='Tmer_Position2fChaserloop='true'/>
158                      < ROUTE  fromNode='Tmer_Position2fChaser' fromField='time' toNode='ScreenPositionDamper_Position2fChaser' toField='Tick'/>
159                 </ProtoBody>
160            </ProtoDeclare>
161            <ProtoDeclare name='PlacementChaser'>
162                 <ProtoInterface>
163                      <field name='isLoadedtype='SFBoolaccessType='outputOnly'/>
164                      <field name='set_valuePostype='SFVec3faccessType='inputOnly'/>
165                      <field name='set_valueOritype='SFRotationaccessType='inputOnly'/>
166                      <field name='set_destinationPostype='SFVec3faccessType='inputOnly'/>
167                      <field name='creditstype='MFStringvalue=' "Initial idea and copyright by Herbert Stocker "http://www.hersto.net/"' accessType='initializeOnly'/>
168                      <field name='durationtype='SFTimevalue='1.0accessType='initializeOnly'/>
169                      <field name='set_destinationOritype='SFRotationaccessType='inputOnly'/>
170                      <field name='initial_valuePostype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
171                      <field name='initial_destinationPostype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
172                      <field name='valuePos_changedtype='SFVec3faccessType='outputOnly'/>
173                      <field name='initial_valueOritype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
174                      <field name='initial_destinationOritype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
175                      <field name='valueOri_changedtype='SFRotationaccessType='outputOnly'/>
176                      <field name='isActivetype='SFBoolaccessType='outputOnly'/>
177                 </ProtoInterface>
178                 <ProtoBody>
179 
                    <!-- ROUTE information for ScreenPositionDamper_PlacementChaser node:  [from Tmer_PlacementChaser.time to Tick ] -->
                    <Script DEF='ScreenPositionDamper_PlacementChaser'>
180                           <field name='previousValueOritype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
181                           <field name='Ticktype='SFTimeaccessType='inputOnly'/>
182                           <field name='durationtype='SFTimeaccessType='initializeOnly'/>
183                           <field name='set_destinationOritype='SFRotationaccessType='inputOnly'/>
184                           <field name='bInitializedtype='SFBoolvalue='falseaccessType='initializeOnly'/>
185                           <field name='set_valueOritype='SFRotationaccessType='inputOnly'/>
186                           <field name='previousValuePostype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
187                           <field name='destinationOritype='SFRotationvalue='0.0 0.0 1.0 0.0accessType='initializeOnly'/>
188                           <field name='initial_valueOritype='SFRotationaccessType='initializeOnly'/>
189                           <field name='set_destinationPostype='SFVec3faccessType='inputOnly'/>
190                           <field name='BufferEndTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
191                           <field name='cNumSupportstype='SFInt32value='10accessType='initializeOnly'/>
192                           <field name='set_valuePostype='SFVec3faccessType='inputOnly'/>
193                           <field name='cStepTimetype='SFTimevalue='0.0accessType='initializeOnly'/>
194                           <field name='initial_destinationOritype='SFRotationaccessType='initializeOnly'/>
195                           <field name='BufferOritype='MFRotationaccessType='initializeOnly'/>
196                           <field name='destinationPostype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
197                           <field name='initial_valuePostype='SFVec3faccessType='initializeOnly'/>
198                           <field name='valuePos_changedtype='SFVec3faccessType='outputOnly'/>
199                           <field name='isActivetype='SFBoolaccessType='outputOnly'/>
200                           <field name='initial_destinationPostype='SFVec3faccessType='initializeOnly'/>
201                           <field name='valueOri_changedtype='SFRotationaccessType='outputOnly'/>
202                           <field name='BufferPostype='MFVec3faccessType='initializeOnly'/>
203                           <IS>
204                                <connect nodeField='durationprotoField='duration'/>
205                                <connect nodeField='set_destinationOriprotoField='set_destinationOri'/>
206                                <connect nodeField='set_valueOriprotoField='set_valueOri'/>
207                                <connect nodeField='initial_valueOriprotoField='initial_valueOri'/>
208                                <connect nodeField='set_destinationPosprotoField='set_destinationPos'/>
209                                <connect nodeField='set_valuePosprotoField='set_valuePos'/>
210                                <connect nodeField='initial_destinationOriprotoField='initial_destinationOri'/>
211                                <connect nodeField='initial_valuePosprotoField='initial_valuePos'/>
212                                <connect nodeField='valuePos_changedprotoField='valuePos_changed'/>
213                                <connect nodeField='isActiveprotoField='isActive'/>
214                                <connect nodeField='initial_destinationPosprotoField='initial_destinationPos'/>
215                                <connect nodeField='valueOri_changedprotoField='valueOri_changed'/>
216                           </IS>
  <![CDATA[
          
ecmascript:

function initialize()
{
    CheckInit();
}

function CheckInit()
{
    if(!bInitialized)
    {
        bInitialized= true;  // Init() may call other functions that call CheckInit(). In that case it's better the flag is already set, otherwise an endless loop would occur.
        Init();
    }
}
function Init()
{
    destinationPos= initial_destinationPos;
    destinationOri= initial_destinationOri;

    BufferPos.length=
    BufferOri.length= cNumSupports;

    BufferPos[0]= initial_destinationPos;
    BufferOri[0]= initial_destinationOri;
    for(var C= 1; C<BufferPos.length; C++ )
    {
        BufferPos[C]= initial_valuePos;
        BufferOri[C]= initial_valueOri;
    }

    previousValuePos= initial_valuePos;
    previousValueOri= initial_valueOri;

    cStepTime= duration / cNumSupports;
}
function set_destinationPos(Dest, Now)
{
    CheckInit();

    destinationPos= Dest;
    // Somehow we assign to Buffer[-1] and wait untill this gets shifted into the real buffer.
    // Would we assign to Buffer[0] instead, we'd have no delay, but this would create a jump in the
    // output because Buffer[0] is associated with a value in the past.

    //UpdateBuffer(Now);
}

function set_destinationOri(Dest, Now)
{
    CheckInit();

    destinationOri= Dest;
    // Somehow we assign to Buffer[-1] and wait untill this gets shifted into the real buffer.
    // Would we assign to Buffer[0] instead, we'd have no delay, but this would create a jump in the
    // output because Buffer[0] is associated with a value in the past.

    //UpdateBuffer(Now);
}
function Tick(Now)
{
    CheckInit();

    if(!BufferEndTime)
    {
        BufferEndTime= Now; // first event we received, so we are in the initialization phase.

        valuePos_changed= initial_valuePos;
        valueOri_changed= initial_valueOri;
        return;
    }

    var Frac= UpdateBuffer(Now);
    // Frac is a value in   0 <= Frac < 1.

    // Now we can calculate the output.
    // This means we calculate the delta between each entry in Buffer and its previous
    // entries, calculate the step response of each such step and add it to form the output.

    // The oldest vaule Buffer[Buffer.length - 1] needs some extra thought, because it has
    // no previous value. More exactly, we haven't stored a previous value anymore.
    // However, the step response of that missing previous value has already reached its
    // destination, so we can - would we have that previous value - use this as a start point
    // for adding the step responses.
    // Actually UpdateBuffer(.) maintains this value in

    var OutputPos= previousValuePos;
    var OutputOri= previousValueOri;

    var DeltaInPos= BufferPos[BufferPos.length - 1].subtract(previousValuePos);
    var DeltaInOri= previousValueOri.inverse().multiply(BufferOri[BufferOri.length - 1]);

    var DeltaOutPos= DeltaInPos.multiply(StepResponse((BufferPos.length - 1 + Frac) * cStepTime));

    OutputPos= OutputPos.add(DeltaOutPos);
    OutputOri= OutputOri.slerp(OutputOri.multiply(DeltaInOri), StepResponse((BufferOri.length - 1 + Frac) * cStepTime));

    for(var C= BufferPos.length - 2; C>=0; C-- )
    {
        var DeltaInPos= BufferPos[C].subtract(BufferPos[C + 1]);
        var DeltaInOri= BufferOri[C + 1].inverse().multiply(BufferOri[C]);

        var DeltaOutPos= DeltaInPos.multiply(StepResponse((C + Frac) * cStepTime));

        OutputPos= OutputPos.add(DeltaOutPos);
        OutputOri= OutputOri.slerp(OutputOri.multiply(DeltaInOri), StepResponse((C + Frac) * cStepTime));
    }
    if(OutputPos != valuePos_changed)
        valuePos_changed= OutputPos;

    if(OutputOri != valueOri_changed)
        valueOri_changed= OutputOri;
}
function UpdateBuffer(Now)
{
    var Frac= (Now - BufferEndTime) / cStepTime;
    // is normally < 1. When it has grown to be larger than 1, we have to shift the array because the step response
    // of the oldest entry has already reached its destination, and it's time for a newer entry.
    // has already reached it
    // In the case of a very low frame rate, or a very short cStepTime we may need to shift by more than one entry.

    if(Frac >= 1)
    {
        var NumToShift= Math.floor(Frac);
        Frac-= NumToShift;

        if(NumToShift < BufferPos.length)
        {   // normal case.

            previousValuePos= BufferPos[BufferPos.length - NumToShift];
            previousValueOri= BufferOri[BufferOri.length - NumToShift];

            for(var C= BufferPos.length - 1; C>=NumToShift; C-- )
            {
                BufferPos[C]= BufferPos[C - NumToShift];
                BufferOri[C]= BufferOri[C - NumToShift];
            }

            for(var C= 0; C<NumToShift; C++ )
            {
                // Hmm, we have a destination value, but don't know how it has
                // reached the current state.
                // Therefore we do a linear interpolation from the latest value in the buffer to destination.

                var Alpha= C / NumToShift;

                BufferPos[C]= BufferPos[NumToShift].multiply(Alpha).add(destinationPos.multiply((1 - Alpha)));
                BufferOri[C]= destinationOri.slerp(BufferOri[NumToShift], Alpha);
            }
        }else
        {
            // degenerated case:
            //
            // We have a _VERY_ low frame rate...
            // we can only guess how we should fill the array.
            // Maybe we could write part of a linear interpolation
            // from Buffer[0] to destination, that goes from BufferEndTime to Now
            // (possibly only the end of the interpolation is to be written),
            // but if we rech here we are in a very degenerate case...
            // Thus we just write destination to the buffer.

            previousValuePos= NumToShift == BufferPos.length? BufferPos[0] : destinationPos;
            previousValueOri= NumToShift == BufferOri.length? BufferOri[0] : destinationOri;

            for(var C= 0; C<BufferPos.length; C++ )
            {
                BufferPos[C]= destinationPos;
                BufferOri[C]= destinationOri;
            }
        }
        BufferEndTime+= NumToShift * cStepTime;
    }
    return Frac;
}
function StepResponse(t)
{
    if(t < 0)
        return 0;

    if(t > duration)
        return 1;

    // When optimizing for speed, the above two if(.) cases can be omitted,
    // as this funciton will not be called for values outside of 0..duration.

    return StepResponseCore(t / duration);
}


// This function defines the shape of how the output responds to the input.
// It must accept values for T in the range 0 <= T <= 1.
// In order to create a smooth animation, it should return 0 for T == 0,
// 1 for T == 1 and be sufficient smooth in the range 0 <= T <= 1.

// It should be optimized for speed, in order for high performance. It's
// executed Buffer.length + 1 times each simulation tick.
function StepResponseCore(T)
{
    return .5 - .5 * Math.cos(T * Math.PI);
}

// The following functions are not used. They provide other responses (for fun).
function StepResponseCoreF(T)
{
    var cTau= .3;
    var cFrequency= 2.5;
    return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T) * (1 - T);
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI));
//      return 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (.5 + .5 * Math.cos(T * Math.PI))* (.5 + .5 * Math.cos(T * Math.PI));
}
function StepResponseCoreE(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin(Math.sqrt(1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}
function StepResponseCoreD(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cFrequency= 2.5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.sin((1 - T) * Math.PI/2);

    return A * .8 + B * .2;
}
function StepResponseCoreC(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) * Math.exp(-T / cTau) * (1 - T);

    return A * .8 + B * .2;
}


function StepResponseCoreB(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    return A * .8 + B * .2;
}
function StepResponseCoreA(T)
{
    var A= .5 - .5 * Math.cos(T * Math.PI);

    var cTau= .3;
    var cFrequency= 5;
    var B= 1 - Math.cos(T * 2 * Math.PI * cFrequency) /** Math.exp(-T / cTau)*/ * (1 - T);

    var Alpha= .2 * T;
    return A * (1 - Alpha) + B * Alpha;
}

        
]]>
218                      </Script>
219 
                    <!-- ROUTE information for Tmer_PlacementChaser node:  [from time to ScreenPositionDamper_PlacementChaser.Tick ] -->
                    <TimeSensor DEF='Tmer_PlacementChaserloop='true'/>
220                      < ROUTE  fromNode='Tmer_PlacementChaser' fromField='time' toNode='ScreenPositionDamper_PlacementChaser' toField='Tick'/>
221                      <Script DEF='LastNode'>
222                           <field name='isLoadedtype='SFBoolaccessType='outputOnly'/>
223                           <IS>
224                                <connect nodeField='isLoadedprotoField='isLoaded'/>
225                           </IS>
  <![CDATA[
          
ecmascript:

function initialize()
{
    isLoaded= true;
}

        
]]>
227                      </Script>
228                 </ProtoBody>
229            </ProtoDeclare>
230            <ProtoDeclare name='PositionDamper'>
231                 <ProtoInterface>
232                      <field name='isLoadedtype='SFBoolaccessType='outputOnly'/>
233                      <field name='value_changedtype='SFVec3faccessType='outputOnly'/>
234                      <field name='set_destinationtype='SFVec3faccessType='inputOnly'/>
235                      <field name='takeFirstInputtype='SFBoolvalue='trueaccessType='initializeOnly'/>
236                      <field name='initial_destinationtype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
237                      <field name='ordertype='SFInt32value='1accessType='initializeOnly'/>
238                      <field name='creditstype='MFStringvalue=' "Initial idea and copyright by Herbert Stocker "http://www.hersto.net/"' accessType='initializeOnly'/>
239                      <field name='reachThresholdtype='SFFloatvalue='0.01accessType='initializeOnly'/>
240                      <field name='tautype='SFFloatvalue='1.0accessType='inputOutput'/>
241                      <field name='set_valuetype='SFVec3faccessType='inputOnly'/>
242                      <field name='reachedtype='SFBoolaccessType='outputOnly'/>
243                      <field name='initial_valuetype='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
244                      <field name='isActivetype='SFBoolaccessType='outputOnly'/>
245                      <field name='epstype='SFFloatvalue='0.0010accessType='initializeOnly'/>
246                 </ProtoInterface>
247                 <ProtoBody>
248                      <ProtoDeclare name='EFFS'>
249                           <ProtoInterface>
250                                <field name='tautype='SFFloatvalue='1.0accessType='inputOutput'/>
251                           </ProtoInterface>
252                           <ProtoBody>
253                                <Group/>
254                           </ProtoBody>
255                      </ProtoDeclare>
256 
                    <!-- ProtoInstance EFFS is a DEF node that has 1 USE node: USE_1 -->
                    <ProtoInstance name='EFFSDEF='EFFS'>
257                           <fieldValue name='tauvalue='1.0'/>
258                      </ProtoInstance>
259 
                    <!-- ROUTE information for Worker node:  [from Timer_PositionDamper.time to tick ] [from needTimer to Timer_PositionDamper.enabled ] -->
                    <Script DEF='Worker'>
260                           <field name='set_valuetype='SFVec3faccessType='inputOnly'/>
261                           <field name='IsCortonatype='SFBoolvalue='falseaccessType='initializeOnly'/>
262                           <field name='bInitializedtype='SFBoolvalue='falseaccessType='initializeOnly'/>
263                           <field name='reachThresholdtype='SFFloataccessType='initializeOnly'/>
264                           <field name='lastTicktype='SFTimevalue='0.0accessType='initializeOnly'/>
265                           <field name='bNeedToTakeFirstInputtype='SFBoolvalue='trueaccessType='initializeOnly'/>
266                           <field name='value5type='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
267                           <field name='value4type='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
268                           <field name='value3type='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
269                           <field name='value2type='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
270                           <field name='inputtype='SFVec3faccessType='initializeOnly'/>
271                           <field name='value1type='SFVec3fvalue='0.0 0.0 0.0accessType='initializeOnly'/>
272                           <field name='epstype='SFFloataccessType='initializeOnly'/>
273                           <field name='set_destinationtype='SFVec3faccessType='inputOnly'/>
274                           <field name='value_changedtype='SFVec3faccessType='outputOnly'/>
275                           <field name='tautype='SFFloatvalue='1.0accessType='initializeOnly'/>
276                           <field name='effstype='SFNodeaccessType='initializeOnly'>
277                                <ProtoInstance USE='EFFS'/>
278                           </field>
279                           <field name='ordertype='SFInt32accessType='initializeOnly'/>
280                           <field name='needTimertype='SFBoolaccessType='outputOnly'/>
281                           <field name='ticktype='SFTimeaccessType='inputOnly'/>
282                           <field name='set_tautype='SFFloataccessType='inputOnly'/>
283                           <field name='initial_valuetype='SFVec3faccessType='initializeOnly'/>
284                           <field name='reachedtype='SFBoolaccessType='outputOnly'/>
285                           <field name='takeFirstInputtype='SFBoolaccessType='initializeOnly'/>
286                           <IS>
287                                <connect nodeField='set_valueprotoField='set_value'/>
288                                <connect nodeField='reachThresholdprotoField='reachThreshold'/>
289                                <connect nodeField='inputprotoField='initial_destination'/>
290                                <connect nodeField='epsprotoField='eps'/>
291                                <connect nodeField='set_destinationprotoField='set_destination'/>
292                                <connect nodeField='value_changedprotoField='value_changed'/>
293                                <connect nodeField='orderprotoField='order'/>
294                                <connect nodeField='needTimerprotoField='isActive'/>
295                                <connect nodeField='initial_valueprotoField='initial_value'/>
296                                <connect nodeField='reachedprotoField='reached'/>
297                                <connect nodeField='takeFirstInputprotoField='takeFirstInput'/>
298                           </IS>
  <![CDATA[
          
ecmascript:

function StartTimer()
{
    if(IsCortona)
        return;

    if(!needTimer)
    {
        lastTick= 0;
        needTimer= true;
    }
}

function StopTimer()
{
    if(IsCortona)
        return;

    if(needTimer)
    {
        needTimer= false;
    }
}

function initialize()
{
    CheckInit();
}

function CheckInit()
{
    if(!bInitialized)
    {
        bInitialized= true;
        Init();
    }

}

function Init()
{
    IsCortona= false && Browser.getName().indexOf('Cortona') != -1;

    bNeedToTakeFirstInput= takeFirstInput;

    tau= effs.tau;
    set_value(initial_value);
    if(IsCortona)
        needTimer= true;
    else
        needTimer=    input.x != initial_value.x
                   || input.y != initial_value.y
                   || input.z != initial_value.z
                   ;
}

function set_tau(t)
{
    CheckInit();

    tau= t;
}

function set_destination(i)
{
    CheckInit();

    if(bNeedToTakeFirstInput)
    {
        bNeedToTakeFirstInput= false;
        set_value(i);
    }


    if(i != input)
    {
        input= i;
        StartTimer();
    }
}

function set_value(o)
{
    CheckInit();

    bNeedToTakeFirstInput= false;

    value1= value2= value3= value4= value5= o;
    value_changed= o;
    UpdateReached();
    StartTimer();
}

function tick(now)
{
    CheckInit();

    if(!lastTick)
    {
        lastTick= now;
        return;
    }

    var delta= now - lastTick;
    lastTick= now;

    var alpha= Math.exp(-delta / tau);


    if(bNeedToTakeFirstInput)  // then don't do any processing.
        return;

    value1= order > 0 && tau
               ? input  .add(value1.subtract(input  ).multiply(alpha))
               : input;

    value2= order > 1 && tau
               ? value1.add(value2.subtract(value1).multiply(alpha))
               : value1;

    value3= order > 2 && tau
               ? value2.add(value3.subtract(value2).multiply(alpha))
               : value2;

    value4= order > 3 && tau
               ? value3.add(value4.subtract(value3).multiply(alpha))
               : value3;

    value5= order > 4 && tau
               ? value4.add(value5.subtract(value4).multiply(alpha))
               : value4;

    var dist= GetDist();

    if(dist < eps)
    {
        value1= value2= value3= value4= value5= input;

        value_changed= input;
        UpdateReached2(dist);

        StopTimer();
        return;
    }
    value_changed= value5;
    UpdateReached2(dist);

}

function GetDist()
{
    var dist= value1.subtract(input).length();
    if(order > 1)
    {
        var dist2= value2.subtract(value1).length();
        if( dist2 > dist)  dist= dist2;
    }
    if(order > 2)
    {
        var dist3= value3.subtract(value2).length();
        if( dist3 > dist)  dist= dist3;
    }
    if(order > 3)
    {
        var dist4= value4.subtract(value3).length();
        if( dist4 > dist)  dist= dist4;
    }
    if(order > 4)
    {
        var dist5= value5.subtract(value4).length();
        if( dist5 > dist)  dist= dist5;
    }
    return dist;
}

function UpdateReached()
{
    return UpdateReached2(GetDist());
}

function UpdateReached2(Dist)
{
    if(reached)
    {
        if(Dist > reachThreshold)
            reached= false;
    }else
    {
        if(Dist <= reachThreshold)
            reached= true;
    }
}

        
]]>
300                      </Script>
301 
                    <!-- ROUTE information for Timer_PositionDamper node:  [from Worker.needTimer to enabled ] [from time to Worker.tick ] -->
                    <TimeSensor DEF='Timer_PositionDamperloop='true'/>
302                      < ROUTE  fromNode='Worker' fromField='needTimer' toNode='Timer_PositionDamper' toField='enabled'/>
303                      < ROUTE  fromNode='Timer_PositionDamper' fromField='time' toNode='Worker' toField='tick'/>
304                 </ProtoBody>
305            </ProtoDeclare>
306       </Scene>
307  </X3D>
<!--

<!--
Event Graph ROUTE Table shows event connections.
-->

<!-- to top Index for DEF nodes: EFFS, LastNode, ScreenPositionDamper_OrientationChaser, ScreenPositionDamper_PlacementChaser, ScreenPositionDamper_Position2fChaser, ScreenPositionDamper_PositionChaser, Timer_PositionDamper, Tmer_OrientationChaser, Tmer_PlacementChaser, Tmer_Position2fChaser, Tmer_PositionChaser, Worker

Index for ProtoDeclare definitions: EFFS, OrientationChaser, PlacementChaser, Position2fChaser, PositionChaser, PositionDamper
-->
X3D Tooltips element index: connect, field, fieldValue, Group, head, IS, meta, ProtoBody, ProtoDeclare, ProtoInstance, ProtoInterface, ROUTE, Scene, Script, TimeSensor, WorldInfo, X3D, accessType and type, XML data types, field types

Event Graph ROUTE Table entries with 6 ROUTE connections total, showing X3D event-model relationships for this scene.

Each row shows an event cascade that may occur during a single timestamp interval between frame renderings, as part of the X3D execution model.

Tmer_OrientationChaser
TimeSensor
time
SFTime

ROUTE
event to
(1)
ScreenPositionDamper_OrientationChaser
Script
Tick
SFTime

Tmer_PlacementChaser
TimeSensor
time
SFTime

ROUTE
event to
(1)
ScreenPositionDamper_PlacementChaser
Script
Tick
SFTime

Tmer_Position2fChaser
TimeSensor
time
SFTime

ROUTE
event to
(1)
ScreenPositionDamper_Position2fChaser
Script
Tick
SFTime

Tmer_PositionChaser
TimeSensor
time
SFTime

ROUTE
event to
(1)
ScreenPositionDamper_PositionChaser
Script
Tick
SFTime

LastNode
Script
No ROUTE connection found for output events from this node.
This Script has no direct access to other nodes. 

      ScreenPositionDamper_OrientationChaser
Script
No ROUTE connection found for output events from this node.
This Script has no direct access to other nodes. 

      ScreenPositionDamper_PlacementChaser
Script
No ROUTE connection found for output events from this node.
This Script has no direct access to other nodes. 

      ScreenPositionDamper_Position2fChaser
Script
No ROUTE connection found for output events from this node.
This Script has no direct access to other nodes. 

      ScreenPositionDamper_PositionChaser
Script
No ROUTE connection found for output events from this node.
This Script has no direct access to other nodes. 

     
The following ROUTE chain begins an event-routing loop! Loop occurs at nodeDepth=3.
 
ROUTE Worker.needTimer TO Timer_PositionDamper.enabled
Worker
Script
needTimer
SFBool

ROUTE
event to
(1)
Timer_PositionDamper
TimeSensor
enabled
SFBool
then
 
 
 
Timer_PositionDamper
TimeSensor
time
SFTime

ROUTE
event to
(2)
Worker
Script
tick
SFTime
then
 
 
 
Worker
Script
needTimer
SFBool

ROUTE
event to
(3)
Timer_PositionDamper
TimeSensor
enabled
SFBool
then
 
 
 
Timer_PositionDamper
TimeSensor
time
SFTime

ROUTE
event to
(4)
Worker
Script
tick
SFTime
then
 
 
 
Worker
Script
needTimer
SFBool

ROUTE
event to
(5)
Timer_PositionDamper
TimeSensor
enabled
SFBool
then
 
 
 
Timer_PositionDamper
TimeSensor
time
SFTime

ROUTE
event to
(6)
Worker
Script
tick
SFTime

EFFS
ProtoInstance
EFFS
No ROUTE connection found for output events from this node.
This ProtoInstance contains SFNode/MFNode fieldValue declarations with
direct access to other nodes, and thus has potential to produce run-time animation. 
Additional guidance on X3D animation can be found in the 10-Step Animation Design Process and Event Tracing hint sheets. Have fun with X3D! 😀

-->
<!-- Online at
https://www.web3d.org/x3d/content/examples/Basic/Followers/FollowerPrototypeDeclarationsIndex.html -->
<!-- Version control at
https://sourceforge.net/p/x3d/code/HEAD/tree/www.web3d.org/x3d/content/examples/Basic/Followers/FollowerPrototypeDeclarations.x3d -->

<!-- Color legend: X3D terminology <X3dNode DEF='idName' field='value'/> matches XML terminology <XmlElement DEF='idName' attribute='value'/>
(Light-blue background: event-based behavior node or statement) (Grey background inside box: inserted documentation) (Magenta background: X3D Extensibility)
    <ProtoInstance name='ProtoName'> <field name='fieldName'/> </ProtoInstance> -->

to top <!-- For additional help information about X3D scenes, please see X3D Tooltips, X3D Resources, and X3D Scene Authoring Hints. -->