[x3d-public] Transforms -> HAnimJoints

[GPU Group]

I think bvhacker was doing something with quaternions. Maybe I missed
something.

On Fri, Aug 25, 2023 at 12:44 PM John Carlson <yottzumm at gmail.com> wrote:

> Yeah, I was trying to write quaternions on shoulder stuff to get from A
> Pose to I Pose.
>
> If you have a good test suite, please share.  One thing that I found out
> was you're supposed to multiply on the left of center by the quaternion and
> on the right by the inverse quaternion???  Online documentation goes all
> over the board.  I'm thinking of resorting to THREE.js. Maybe The C/C++/C#
> SAI has something?
>
>
> Thanks,
>
> John
>
> On Fri, Aug 25, 2023 at 1:36 PM GPU Group <gpugroup at gmail.com> wrote:
>
>> John, that's great we'll need you.
>> I haven't worked on the blender exporter in weeks, you are welcome to
>> start that HAnim export part if you like.
>> https://github.com/dug9/BlenderX3DSupport
>> Right now I'm struggling to load .bvh files at random with bvhacker
>> https://github.com/DaveDubUK/bvhacker as a cleaning tool.  There are
>> lots of recorded bvh motion files to download and use. But even bvhacker
>> needs work -- for example ensuring  Y-UP (blender exports .bvh Z-UP),
>> mapping to HAnim LOA names/selecting the right LOA, ARMS_DOWN default pose.
>> For example when using a T-pose .bvh file (the T geometry is recorded in
>> the OFFSETs field and angles are relative to that pose) on an ARMS_DOWN
>> HAnim, the shoulder/arm rotations aren't correct. BVHacker does some
>> channel swapping X--Y, but similar technique in freewrl doesn't work
>> reliably (yet).
>> SUMMARY: I'm in the same zone with the hanim transforms but stuck back a
>> few steps in getting freewrl to play a .bvh with good shoulder animation.
>> So stuck for a while but open to coordinating with you on HAnim and blender
>> exporter.
>> -Doug
>>
>> On Fri, Aug 25, 2023 at 12:21 PM John Carlson <yottzumm at gmail.com> wrote:
>>
>>> Doug,
>>>
>>> I have some code I've been working on that converts VRML Transforms
>>> with DEFs to HAnimJoints.  Maybe we should collaborate on Hanim Blender
>>> export. I'm also looking for something that will apply transforms to joint
>>> centers, if you have something tested and separate from FreeWRL.
>>>
>>> Thanks,
>>>
>>> John
>>>
>>
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