Hello,

We are developing an automated skeleton animation system and are looking for a
rendering platform to display our results.  Our system currently outputs
control objects for a biped (we are basically creating an animated skeleton or
set of rigid control bones).  We have used 3DS-Max to convert our bone
animation into a final character animation.  We would like to render our output
using POV-Ray, but need to find a good solution for the skin deformations that
Max provides.

For example, in Max, we can create a NURBS point surface model for the skin and
apply a skin deformation controller to the NURBS control points.  The skin
controller is driven by the position of our bones objects, and the result is a
very nice smooth animated biped.  The skin deformation controller lets us
easily specify the bone influence over the NURBS control points.

We are looking for the following:

1) A skin deformation utility that can deform a NURBS model using a set of
control bones as input and produce POV-Ray compatible output (using Bezier
Patches).  We would supply the bone transformations for each frame.  We would
like to be able to edit the control influence of each bone on the various NURBS
control points.

2) A good NURBS modeler that would be compatible with the above.

We would run this utility for each frame.  We have also considered using
polygon-meshes for the skin.

Any ideas or links to existing utilities would be greatly appreciated.  Links to
good papers on the subject would also be a great help.  Thanks!

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"Dave" <nomail@nomail> wrote in message 
news:web.47cf73706e7558949612e0670@news.povray.org...
> Hello,
>
> We are developing an automated skeleton animation system and are looking 
> for a
> rendering platform to display our results.  Our system currently outputs
> control objects for a biped (we are basically creating an animated 
> skeleton or
> set of rigid control bones).  We have used 3DS-Max to convert our bone
> animation into a final character animation.  We would like to render our 
> output
> using POV-Ray, but need to find a good solution for the skin deformations 
> that
> Max provides.

Hi Dave,

I've not seen anything that does precisely this, and, judging by the lack of 
responses to your posting it doesn't seem like anyone else has either. There 
are utilities such as PoseRay that convert other formats into POV-Ray mesh 
or mesh2 objects.

>
> We are looking for the following:
>
> 1) A skin deformation utility that can deform a NURBS model using a set of
> control bones as input and produce POV-Ray compatible output (using Bezier
> Patches).  We would supply the bone transformations for each frame.  We 
> would
> like to be able to edit the control influence of each bone on the various 
> NURBS
> control points.
>

I've seen a couple of examples of skin deformation done in POV-Ray and have 
done some myself, but I don't recall seeing any published source code. The 
POV-Ray macros I wrote manipulate skin surface points that are stored in a 
POV-Ray array, applying deformations based upon joint rotations. I've then 
got further macros to generate mesh objects from the arrays. The deformation 
macros that I wrote are different for each type of joint. I only got as far 
as doing the eye lids and the finger joints.

>
> 2) A good NURBS modeler that would be compatible with the above.
>
> We would run this utility for each frame.  We have also considered using
> polygon-meshes for the skin.
>

If you already have skin shapes for each frame in a format that PoseRay can 
handle, then it sounds like problem solved? I think that most human 
animation in POV-Ray is handled this way with a frame by frame export from a 
human modelling application.

> Any ideas or links to existing utilities would be greatly appreciated.
> Links to good papers on the subject would also be a great help.
> Thanks!

Material related to doing human animation in POV-Ray is currently pretty 
light on the ground. I like to think that the most mature attempt was my 
POV-Person library at http://www.geocities.com/povperson/.

Before that, the only humanoid I'm aware of done solely in POV-Ray was a 
very old thing called Blobman. Terresa Willis did a walking animation many 
moons ago, but that was of a solid robotic form. A couple of old hands have 
incorporated Poser models and I recall seeing a decent walking animation 
done using Poser a long time ago.

There was an impressive muscle deformation animation a couple of years back 
on the povray.binaries.animations newsgroup, but it only did the arm 
muscles. I've done a few macros since POV-Person to do the finger and eyelid 
deformations I mentioned above and one to do dynamic hair.

Maybe this posting will prompt people to remember other stuff that could be 
relevant.

Regards
Chris B.

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