[x3d-public] Extrusions, take 3
John Carlson
yottzumm at gmail.com
Tue Jan 26 21:53:31 PST 2016
So if one has to take a line segment and transform it to another line segment in space, what’s the typical algorithm to do that? I probably used to know this. I was trying to work it out again a while back.
Do the new declarative nodes in V4+ support this? Or the old nodes in V3? Or does one need a script? Is there a node with a linear transform defined by 12 numbers (4 SFVec3f)? Could there be?
2 PositionInterpolators? Then how does that become a transform?
Thanks,
John
> On Jan 27, 2016, at 12:33 AM, John Carlson <yottzumm at gmail.com> wrote:
>
> Better yet, define a script which takes two endpoints on a geometry, then transform the two endpoints (and thus the geometry) with the script. Hm. I might be able to do this myself. Hmm.
> Sound more possible with Cylinders defined by X3D now. Took me long enough.
>
> John
>> On Jan 27, 2016, at 12:26 AM, John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>> wrote:
>>
>> I just realized the code was online here:
>>
>> https://github.com/coderextreme/X3DJSONLD/blob/master/force.x3dhttps://github.com/coderextreme/X3DJSONLD/blob/master/force.x3d <https://github.com/coderextreme/X3DJSONLD/blob/master/force.x3dhttps://github.com/coderextreme/X3DJSONLD/blob/master/force.x3d>
>>
>> (click raw)
>>
>> Here’s the challenge. Define an IFS by two endpoints, and then move those endpoints around with minimal scripting (Declarative 3D).
>>
>> John
>>> On Jan 26, 2016, at 11:45 PM, John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>> wrote:
>>>
>>> I am not "modeling" I am doing declarative 3d as much as possible and scripting the rest. Thus I am creating protos for edges and nodes of a 3D graph. I currently use ROUTES to link the edges (cylinders/extrusions) to the nodes (spheres). I am using position interpolators to animate the nodes, and routes to update the spline of the edges. I do not understand how to use Cylinders as defined by X3D in this way so I use extrusions. If you can suggest a way to implement a 3D graph without extrusions, I would be welcome to hear it. I can provide source code if you like. I have posted force.x3d here, or you can look at force.json in https://github.com/coderextreme/X3DJSONLD/ <https://github.com/coderextreme/X3DJSONLD/>
>>> On Jan 26, 2016 11:27 PM, "Leonard Daly" <Leonard.Daly at realism.com <mailto:Leonard.Daly at realism.com>> wrote:
>>> On 1/26/2016 5:21 PM, John Carlson wrote:
>>>> All I would really like to see is an easy way to define Cylinder with 2 endpoints and a radius. If that is provided, I have no problem with deprecating Extrusion from the standard.
>>>> I do not think defining a Cylinder in this way would be onerous to a run-time, but I could be wrong. If someone could provide an example of a Cylinder like this, it would be great!
>>>
>>> John,
>>>
>>> You using Extrusion to define a cylinder with known endpoints, as opposed to using a Transform {Shape {Cylinder}} to do that based on the center point and height then rotated & translated into place.
>>>
>>> I gather you are doing your modeling by hand in a text or xml editor (like X3D-Edit). There is almost no commercial modeling-by-hand. I do not know of any professional or amateur modeler creating commercial quality models working that way. I think you will find a tool like Blender solves a lot of your modeling issues.
>>>
>>>
>>> Leonard Daly
>>>
>>>
>>>
>>>
>>>> John
>>>>> On Jan 26, 2016, at 8:13 PM, John Carlson <yottzumm at gmail.com> <mailto:yottzumm at gmail.com> wrote:
>>>>>
>>>>> Uh, I asked for an IndexedFaceSet. Thanks, though.
>>>>>
>>>>> John
>>>>>> On Jan 26, 2016, at 8:11 PM, doug sanden <highaspirations at hotmail.com> <mailto:highaspirations at hotmail.com> wrote:
>>>>>>
>>>>>>
>>>>>> http://dug9.users.sourceforge.net/web3d/tests/41.x3d <http://dug9.users.sourceforge.net/web3d/tests/41.x3d>
>>>>>>
>>>>>> snake animation animating extrusion spine
>>>>>>
>>>>>> From: x3d-public [x3d-public-bounces at web3d.org <mailto:x3d-public-bounces at web3d.org>] on behalf of John Carlson [yottzumm at gmail.com <mailto:yottzumm at gmail.com>]
>>>>>> Sent: January 26, 2016 6:04 PM
>>>>>> To: Leonard Daly
>>>>>> Cc: x3d-public at web3d.org <mailto:x3d-public at web3d.org>
>>>>>> Subject: Re: [x3d-public] Extrusions, take 3
>>>>>>
>>>>>> Maybe just show an example of an IndexedFaceSet which is an extrusion of a circle with 3 spline points, with the “bend” animated from 90 to 180 degrees.
>>>>>>
>>>>>> It’s okay to use Blender or Maya, I’d just like to see what the results look like.
>>>>>>
>>>>>> John
>>>>>> On Jan 26, 2016, at 8:01 PM, John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com><mailto:yottzumm at gmail.com> <mailto:yottzumm at gmail.com>> wrote:
>>>>>>
>>>>>> So how do you propose to animate IndexedFaceSets in a declarative or VRMLscript or JavaScript manner if they are Extrusions? Can we see an example? If the developer has to do it, can we help them?
>>>>>>
>>>>>> John
>>>>>> On Jan 26, 2016, at 6:58 PM, Leonard Daly <Leonard.Daly at realism.com <mailto:Leonard.Daly at realism.com><mailto:Leonard.Daly at realism.com> <mailto:Leonard.Daly at realism.com>> wrote:
>>>>>>
>>>>>> On 1/26/2016 3:21 PM, John Carlson wrote:
>>>>>> Leonard, I think you forget that Extrusion splines etc. can be animated. If Maya can export an Extrusion animation to X3D V4.0 and your new elements can handle animation of it, I think we are fine.
>>>>>>
>>>>>> In Maya and Blender, extrusions are converted to IndexedFaceSets. These can be animated through the usual mechanisms in those applications. The results are typically stored in a FBX file. Unfortunately, the FBX format is not open and not too conducive to importing in a browser. Autodesk provides a C++ and Python API for accessing the file.
>>>>>>
>>>>>> Extrusions are just a convenience node for creating a constrained IndexedFaceSet. I am working on exactly how X3D fits in the process chain from modeling tools to display. The goal is that X3D is an declarative archivable format that has a browser-based run time. The goal is to not reduce the display capability of X3D in that chain; however, not all of the functionality of X3D V3.3 is necessary to remain in the node definitions to make that happen.
>>>>>>
>>>>>> Animation of the spline and cross-sections of an extrusion is much easier for the developer, but puts a much greater load on the run-time as it needs to re-triangulate the result on each animation.
>>>>>>
>>>>>>
>>>>>> Leonard Daly
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> John
>>>>>> On Jan 26, 2016, at 1:47 PM, Leonard Daly <<mailto:Leonard.Daly at realism.com> <mailto:Leonard.Daly at realism.com>Leonard.Daly at realism.com <mailto:Leonard.Daly at realism.com><mailto:Leonard.Daly at realism.com> <mailto:Leonard.Daly at realism.com>> wrote:
>>>>>>
>>>>>> I would like to ask the question very differently. My question is not to ignore the importance of getting the definition correct for X3D <= V3.3.
>>>>>>
>>>>>>
>>>>>> Most (>95%) 3D modeling is done with a tool. In non-CAD environment, the tools is almost certainly Maya or Blender. Both of those tools have extrusions built in to their interface. I imagine CAD tools are similar. With so many tools providing graphical extrusion editors, and some of the tools being open-source (at least Blender);
>>>>>>
>>>>>> Do we need an extrusion node in V4 to support content developed for V4+?
>>>>>>
>>>>>>
>>>>>> Leonard Daly
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 1/26/2016 7:15 AM, Alekseyev, Vsevolod (NIH/NIAID) [E] wrote:
>>>>>> Hi X3D community,
>>>>>>
>>>>>> I've tried and failed twice to explain the problems with the definition of the Extrusion node. So here's a tl;dr version:
>>>>>>
>>>>>> Dear authors of the X3D standard, please take a careful look at the standard and answer me:
>>>>>>
>>>>>> 1) When the spine goes (0,0,0)-(0,-1,0), what is the CSP?
>>>>>> Note: all answers but one will render one of the reference models in the Savage archive invalid.
>>>>>>
>>>>>> 2) When the spine goes (0,0,0)-(0,1,0)-(0,0,0), what is the CSP?
>>>>>>
>>>>>> 3) When the spine goes (0,0,0)-(1,1,0)-(1,1,0)-(1,1,0)-(2,0,0), what is the CSP for the three middle points?
>>>>>>
>>>>>>
>>>>>>
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>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Leonard Daly
>>>>>> 3D Systems & Cloud Consultant
>>>>>> X3D Co-Chair on Sabbatical
>>>>>> LA ACM SIGGRAPH Chair
>>>>>> President, Daly Realism - Creating the Future
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>>>>>>
>>>>>>
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>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Leonard Daly
>>>>>> 3D Systems & Cloud Consultant
>>>>>> X3D Co-Chair on Sabbatical
>>>>>> LA ACM SIGGRAPH Chair
>>>>>> President, Daly Realism - Creating the Future
>>>>>> _______________________________________________
>>>>>> x3d-public mailing list
>>>>>> x3d-public at web3d.org <mailto:x3d-public at web3d.org><mailto:x3d-public at web3d.org> <mailto:x3d-public at web3d.org>
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>>>>>>
>>>>>>
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>>>
>>>
>>> --
>>> Leonard Daly
>>> 3D Systems & Cloud Consultant
>>> X3D Co-Chair on Sabbatical
>>> LA ACM SIGGRAPH Chair
>>> President, Daly Realism - Creating the Future
>>
>
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