Re: [Maya2osg-users] Blend shapes

[Javier T. <jav...@gm...>]

  Hi Peter,

On Thu, May 19, 2011 at 10:50 AM, Peter Wrobel <pp...@cg...> wrote:
> Hi Javier,
>
> fast answer, but details on mondy.

  OK. Don't worry just ignore the messages if you're busy. We'll
follow the thread next week.

>>    I'm going to export a 3D character with skeleton animation and blend
>> shapes, so I will at last test the osgAnimation export  :)
>
> I wasn't able to add Skinning Code till now, so all yo can export is
> transform animation. My osgMaya exporter has skinning implemented, but
> the merging will take some time, so I don't know how fast I'll get to this.

  OK. Maybe I can help with it. I'll take a look at it when I had some time.

>>    Are blend shapes supported in Maya2OSG? Is there any development? Or
>> may I have to start from scratch?
>
> I started to write the export for that. I stopped as I was a little
> frustrated that you cannot't "chain" the skining and morphing in an osg
> file. Cedric showed me how to do this through code. But now I already
> know more about osg, and I have an Idea what has to be done.
> Datails after monday

  OK. We'll follow the discussion next week.

>>    And about how to prepare the model, it is a pseudo-humanoid
>> character (biped) that will have blend shapes applied only to the
>> face. The artist is asking me whether she should cut out the head to
>> create the blend shapes only there or keep the body geometry as a
>> whole. Is it a problem to rejoin the blend-shaped head later with the
>> rest of the body? Have you ever done it?
>
> This is the "normal" way people do it in the industry. So for the
> begining it would be cool if she would keep the whole body mesh
> attached. Later we should add this functionality, but I don't know how
> far osgANimation needs to support this. Basically in normal morphing you
> blend the position of a point to the position of another point. You
> identify both points with their id. If you screw up point numbering in
> one of the meshes ( by deliting one Vertex somwhere ) you scre up the
> morphing. We would require a map between target and source ids. That we
> can do in the plug in, but can osgAnimation use such a map ? Not shure,
> but I don't think so.

  Yes, I know the blend shape theory. I didn't know however how much
is it supported in osgAnimation.

>>    In case of having the "blend-shaped head" and the body in separate
>> geometries, both affected by the skeleton animation, as long as the
>> vertices in the joint edges are not affected by blend shapes and have
>> assigned the exact same weights in skinning, should it be a problem?
>> Do you think it would produce visible cracks in this part of the
>> geometry?
>
> No, the way you normally di it is, cut the hayd off, but dont' morph the
> border edges. With this you guarantee continuity.

  Yes, that's exactly what I meant. My doubt was, being the geometry
split in two pieces, even though the vertices are in the same place if
there are any problems of edge cracks. I hope not.


-- 
Javier Taibo