[x3d-public] Can you get this X3D animation imported into Blender?

[Joe D Williams]

> One thing that might work is attaching MESH objects to EMPTY objects to Blender bones. 
  
Right, in the hierarchy of' transform objects you are creating for the skeleton, follow the hanim spec and attach mesh geometry to the node representing the correct Segment. This would be exported as a Shape in its correct location in the skeleton hierarchy.
 If there are Site nodes, then also place then in the correct node representing the Segment.

JointA
..Segment
....Shape Level1 segment geometry 
..../Shape
....Site ...accessories/sensors
..../Site
../Segment 
..JointB
    ....
../JointB
/JointA
  
Same as loa4 skeleton, Jin. 
Just name the 'transforms what they represent. 
Does blender use the concept of center for a 'transform' rotation? 
Good names in the hierarchy mean we are able to assign animation values to nodes. 
Only the Joint nodes will receive translation/rotation events. 
First, make sure the starting global coordinate system is like x3d 
so basic skeleton is drawn as expected. 
   
Just in case, I attached the very basic loa4 skeleton text that we want to see as importable to blender, eventually provided as a gui selection to start the the user's avatar and virtual twin simulation experience.  
After All, if you are going to produce a humanoid that can interact anywhere anywhen immersed in our www virtuality, like for the rest of x3d, you might as well start with the World Standard Humanoid, designed to be transportable and use transportable animations, and go from there. 
Even if some AI does all this for us some day, we still want to tell the thing where to start: Official HAnim Standard and x3d HAnim. 
     
Thanks,
Joe
  
-----Original Message-----
From: John Carlson <yottzumm at gmail.com>
Sent: Jun 7, 2024 5:12 PM
To: Joe D Williams <joedwil at earthlink.net>
Cc: GPU Group <gpugroup at gmail.com>, Katy Schildmeyer KS APPAREL DESIGN <katy at ksappareldesign.com>, X3D Graphics public mailing list <x3d-public at web3d.org>
Subject: Re: Can you get this X3D animation imported into Blender?

As I thought I said, the HAnim examples without animation is pretty useless to me right now.  Small examples with animation are helpful.  If someone has a magical type that does HAnim without Blender bone types and/or Objects in Blender, fess up.
 
There’s no issue that i know of loading HAnim into a matrix+transform+object hierarchy statically. The issue right now is getting animations right.  We have a hierarchy, now let’s get the numbers right.
 
One thing that might work is attaching MESH objects to EMPTY objects to Blender bones.  But we’re currently focusing on MESH and EMPTY objects.  Blender bones will be optional in my plan.

 
John 
On Fri, Jun 7, 2024 at 4:55 PM Joe D Williams <joedwil at earthlink.net (mailto:joedwil at earthlink.net)> wrote:
> Major point:  both Blender bones and Skeleton as Transforms should be supported for maximum flexibility.  What are your thoughts?
  
Treat that model as it should have been treated years ago and abandon it. 
That is just a simplified convention they adopted in days of yore duplicating mechanical armature and making stop motion videos with no or minimum computer thus should be updated to use terminology and hierarchy of x3d hanim.  
Number 1 is creating fullhanim  skeleton by using the blender gui or by importing the minimum skeleton I last sent into blender then adjusting that data to be able to export to x3d. 
Then a user can use the example hanim to start with. 
The way we expose the hanim skeleton hierarchy of Joint, Segment, Site is simply to create the hierarchy with names that can be recognized and organize a system of data for export to x3d. 
  
So, recall that if they talk bone orientation, it is the same as joint rotation and vertex weights by bone is same as weights by Joint, when rigged correctly. Same for all, even Unity, because it is a just better way to deal with details. Under the covers the data is the same

The mission is to update blender to hamin from their archaic current abstractions to terms and structures of x3d hanim, or, alternately, get tools like castle, x3dom, xcite, freewrl and others to become more than just a player and add some even simple ways to create and edit the skeleton and geometry and animations and work more directly with authors to create a complete x3d scene. A great example of the old days was viz3d and flux and BS Content studio. The x3d sai is capable of producing a native x3d authoring tool. 

Thanks,
Joe
  

.
 

-----Original Message-----
From: John Carlson <yottzumm at gmail.com (mailto:yottzumm at gmail.com)>
Sent: Jun 6, 2024 1:59 PM
To: GPU Group <gpugroup at gmail.com (mailto:gpugroup at gmail.com)>, Joe D Williams <joedwil at earthlink.net (mailto:joedwil at earthlink.net)>
Cc: Katy Schildmeyer KS APPAREL DESIGN <katy at ksappareldesign.com (mailto:katy at ksappareldesign.com)>, X3D Graphics public mailing list <x3d-public at web3d.org (mailto:x3d-public at web3d.org)>
Subject: Re: Can you get this X3D animation imported into Blender?

Sorry TL;DR.  Major point:  both Blender bones and Skeleton as Transforms should be supported for maximum flexibility.  What are your thoughts?

 
Replying to Joe:
 
Understood.  AFAIK, I still need blender bones to export weights right now, but Blender bones only provide for Joints, not segments or sites (can I attach EMPTYs to Blender bones in a particular  mode?).  I will experiment with attaching weights to EMPTYs (joints),  then on export, I will move weight detection from Blender bones to EMPTYs,  we can do limited mapping on export, but asking someone to map an entire LOA4 skeleton is unrealistic. I don’t even like LOA1-LOA2 in VRM and BVH. Such user-specified mapping should be saved for reuse.  I can already do MoMask BVH joint mapping on export (but not “End Site” yet).  We probably won’t be able to save HAnim  to VRM skeletons, and I think that USDSkel may do armature/bones as well, so I’m not seeing X3D to USD Skel particularly working.  I think Doug suggested a separate skeleton mapping app, perhaps this feasible.  It’s just not realistic with glTF files exported to 8GB-14GB X3D files 200 times the size of a Blender file.
 
The good news is, I got small Transform hierarchies import mostly working in Blender with matrix_local and translation. Now to follow through with centers and HAnim.  Moving like molasses, but with simple examples, things are easier and moving faster without waiting years for import and tons of logging.
 
Katy can comment on rigging and armature in Blender, as what might be missing if we don’t import Blender bones,  this may severely impact the apparel workflow in Blender.
 
Most likely, both paths should be supported.  I hope you are in agreement.  Perhaps separating out the import/export into separate addons would make decisions easier.
 
Your additional thoughts are welcome.

On Thu, Jun 6, 2024 at 2:48 PM Joe D Williams <joedwil at earthlink.net (mailto:joedwil at earthlink.net)> wrote:
> Can we use the same transform code in Blender for both Transform and HAnim? 

Yes, if blender transform operation can use 'center', which Joint needs. Just name the objects so the Humanoid, Joint, Segment, Site transforms can be transcoded at export into into HAnim hierarchy. 
Joe




-----Original Message-----
From: John Carlson <yottzumm at gmail.com (mailto:yottzumm at gmail.com)>
Sent: Jun 6, 2024 5:03 AM
To: Joe D Williams <joedwil at earthlink.net (mailto:joedwil at earthlink.net)>
Cc: Katy Schildmeyer KS APPAREL DESIGN <katy at ksappareldesign.com (mailto:katy at ksappareldesign.com)>, X3D Graphics public mailing list <x3d-public at web3d.org (mailto:x3d-public at web3d.org)>
Subject: Re: Can you get this X3D animation imported into Blender?

Okay, Joe.  Now to get this working in Blender, since you’ve confirmed the behavior.  Thanks!

 
Can we use the same transform code in Blender for both Transform and HAnim?
 
John

On Thu, Jun 6, 2024 at 5:35 AM Joe D Williams <joedwil at earthlink.net (mailto:joedwil at earthlink.net)> wrote:
Hi John, 

You sent this: 

  <Transform DEF="TransformRoot1" center="0 0 0">
    <Shape>
      <Box size='0.5 0.5 0.5'/>
    </Shape>
    <Transform DEF="TransformTargetParent1" center="4 0 0">
      <Shape>
        <Box size='0.5 0.5 0.5'/>
      </Shape>
      <Transform DEF="TransformTargetChild1" center="8 0 0">
        <Shape>
          <Box size='0.5 0.5 0.5'/>
        </Shape>
      </Transform>
    </Transform>
  </Transform>

Not shown here is the interpolator that sends rotations to both Parent and Child Transforms
For this animation code you sent this did exactly what it should have done.
The boxes start at 0 0 0 then are swept along the axis according to the Parent and Child Transform nodes animation input.  
Note that the initial position of all three boxes is 0 0 0, then they move along the radius from where you set the parent centers.

Please have a look at this: 

First, slight change from what you sent. 
Again, a important understanding is that "center" value of the Transform represents the center of rotation of that Transform, and may have nothing much to do with the value for translation, which is 0 0 0 for the parent Transform for each Shape. 

  <Transform DEF="CenterRoot1" center="0 0 0">
    <Shape>
      <Box size='0.5 0.5 0.5'/>
    </Shape>
    <Transform DEF="CenterParent1" center="4 0 0">
      <Shape>
        <Box size='0.5 0.5 0.5'/>
      </Shape>
      <Transform DEF="CenterChild1" center="8 0 0">
        <Shape>
          <Box size='0.5 0.5 0.5'/>
        </Shape>
      </Transform>
    </Transform>
  </Transform>

So again, all Shapes start at 0 0 0 then are swept through the arc defined by each parent Transform center.  

This version operates like the hanim model.
The parent Transform is a "Joint" with center defined, then the Shape has its own Transform to place it at the parent center value.
(The first center="0 2 0" translation='0 2 0' just moves the is example up above the first example.) 

  <Transform DEF="TransformRoot2" center="0 2 0" translation='0 2 0'>
    <Transform DEF="MoveToCenterRoot" translation="0 2 0">
      <Shape>
        <Box size='0.5 0.5 0.5'/>
      </Shape>
    </Transform>
    <Transform DEF="CenterTargetParent2" center="4 0 0">
      <Transform DEF="TranslateTargetParent2" translation="4 0 0">
        <Shape>
          <Box size='0.5 0.5 0.5'/>
        </Shape>
      </Transform>
      <Transform DEF="CenterTargetChild2" center="8 0 0">
        <Transform DEF="TranslateTargetChild2" translation="8 0 0">
          <Shape>
            <Box size='0.5 0.5 0.5'/>
          </Shape>
        </Transform>
      </Transform>
    </Transform>
  </Transform>

In Humanoid space, once the connection between using center to set the Joint center of rotation and then a child Transform to position any associated stuff in Humanoid space just makes it work wonderful for what we need in hanim.

I can recall a day when there were sincere discussions over whether to include the 'center' field in Transform.  

Thanks,
Joe























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