[x3d-public] Extrusions, take 3
John Carlson
yottzumm at gmail.com
Wed Jan 27 04:11:46 PST 2016
Let me guess, there’s some IP that’s preventing us from doing that? Like the dreaded Geo-Vector?
John
> On Jan 27, 2016, at 7:04 AM, John Carlson <yottzumm at gmail.com> wrote:
>
> I guess what I am trying to say is, even though you can specify a cylinder with a central point, a height and a radius, it’s much more convenient to do it with 2 points and a radius. If you need a height, you can subtract and take the normal, whereas getting the second point with a height is very problematic except in one direction. Does anyone disagree?
>
>
>> On Jan 27, 2016, at 12:53 AM, John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com>> wrote:
>>
>> 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 <mailto: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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