Results 1 to 8 of 8

Thread: animations and nodes

  1. #1
    Junior Member
    Join Date
    Oct 2005
    Posts
    24

    animations and nodes

    Hello,

    I discussed that subject a little on the implementation discussions forum, but I guess it's more a design issue : after having read the 1.3.1 specifications, I couldn't find a clear definition of what an <animation> was, except a group of channels.

    More precisely, it says "Animation describes the transformation of an object or value over time.".
    Does that mean an animation should be attached to a node (the "object") ?
    Therefore the target node of an animation would be an attribute of the animation element. But then, what if we wanted to animate instances instead of nodes?

    I have no idea of what the 1.4 specs will add about that as they don't seem to be available before November 4th, but any clue would be helpful even for 1.3 support.

  2. #2
    Senior Member
    Join Date
    Apr 2005
    Location
    Feeling Software, Montreal, Quebec
    Posts
    111
    Hi there!

    An animation, in COLLADA 1.3.1, is just a grouping of <channel>/<sampler>... elements, without any real implied relationship between them.

    The need for more structure was addressed in COLLADA 1.4.0. I don't know how much of it is confidential, so I'll avoid specific details. COLLADA 1.4.0 introduces the idea of animation clips. Each animation clip will group together animation channels (or curves) or segments of animation curves.

    Another addition in COLLADA 1.4.0 is that the animation library becomes hierarchical. The <animation> element can contain the <animation> element and allow you to more easily sort through your animation curves. So, in COLLADA 1.4.0, the <animation> element still won't have any implied relationship for its content, but you should be able to better manage it.

    In COLLADA 1.3.1, the standard doesn't tell you how to instantiate the animations and COLLADA 1.4.0 doesn't address this. Personally, I think this should be left to the engine developers to handle. But at least, you'll have the grouping information which is necessary to use the animations properly.

    Sincerely,
    Guillaume Laforte
    Feeling Software Inc
    http://www.feelingsoftware.com

  3. #3
    Junior Member
    Join Date
    Oct 2005
    Posts
    24
    Hello,

    Each animation clip will group together animation channels (or curves) or segments of animation curves.
    In the case of ColladaMaya, will these animation clips correspond to the Maya "clips" ?

  4. #4
    Senior Member
    Join Date
    Apr 2005
    Location
    Feeling Software, Montreal, Quebec
    Posts
    111
    ColladaMaya does export clip information right now. The support for it is fairly experimental as I haven't heard of anyone using it extensively yet. If you try it out, please share with us your feedback!

    Although it has been some time since I coded this, on the top of my head: to export clips in ColladaMaya, you need to create a character with all the nodes that are animated. Then, you create source clips and clip instances for your animations. The import should create the character, source and clip instances for you.

    Sincerely,
    Guillaume Laforte
    Feeling Software Inc
    http://www.feelingsoftware.com

  5. #5
    Junior Member
    Join Date
    Oct 2005
    Posts
    24
    Hello,

    So far I've tried exporting animation clips with two different sets of settings, without success.

    For both exports, I'm using ColladaMaya 0.88; I have one character binded to one animation clip, which I instantiated once in the trax viewer.

    * The 1st set of export parameters I tried is the following (I tried to export as much information as possible):

    options checked:
    - Polygon meshes
    - Cameras
    - Animations
    - Invisible Nodes
    - Export constraints
    - Lights
    - Joints and skin
    - Export Physics
    - Normals
    - Per-Vertex Colors
    - Texture Tangents
    - Texture Coordinates
    - Geometric Tangents
    - Export References

    ** Results:
    - All my animation channels nodes are listed as animation elements, children of library_animations.
    - I have a library_animation_clips element, which I suppose is a good piece of news, but it is empty.



    * The 2nd set of export parameters I tried was the one I wished I could use for my needs:

    options checked:
    - Bake transforms
    - Export polygons as triangles
    - Sampling 0.016
    - Polygon meshes
    - Animations
    - Joints and skin
    - Normals
    - Export References

    ** Results:
    - All my animation channels nodes are listed as animation elements, children of library_animations.
    - No library_animation_clips element this time

    In both case, I end up with animation elements which ids are like "armJBLf_1_transform-anim" (which are listed first, and don't seem to be related to the sourceclips), and some other animation elements are named like "HE_SW_WLKSource_fkarmJALf_1_rotateZ-animANGLE", HE_SW_WLKSource being the name of my animation clip.

    If you think I could provide you some more useful information to you let me know.
    Thanks for your attention.

  6. #6
    Junior Member
    Join Date
    Oct 2005
    Posts
    24
    Hello;

    It appears that using ColladaMaya v2.01 and Maya 7, I'm still not able to export <animation_clip> elements, and only the main track is being exported in separate <animation> elements.

    Actually, I've been using most of ColladaMaya releases from 0.79, and I don't recall I was ever able to use this feature, so I guess I do something wrong when dealing with animation clips in Maya.

    I can do without exporting <animation_clip> elements, but I thought you might want to know. Thanks anyway for your attention.

  7. #7
    Senior Member
    Join Date
    Jul 2004
    Location
    Santa Clara
    Posts
    356
    Hi,
    Could you do us a favor and report this as a bug on http://www.feelingsoftware.com/bugzilla/ so we can follow-up with this.

    Thanks

  8. #8
    Junior Member
    Join Date
    Oct 2005
    Posts
    24
    Hello,

    Done (Bug 106).

    Thanks!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •