[Bf-committers] Concept bug with Shrinkwrap(projection)+armatures

[Juan Pablo Bouza]

Hi Vicente!

Well, the coder who made shrinkwrap is jaguarandi, you might find him at blendercoders, but this is definitely a feature request, not a bug. Anyway, I don't think shrinkwrap is the right way, another modifier which doesn't use rays calculation should be better. Have you tried the Warp modifier? for a spherical shape it should work.

Now, about your setup, the only way I know of working with shrinkwrap and obtaining good results is nearest surface point + heavy subdivision of the target mesh.

You should think of your setup in the opposite way, as now you are working with nearest surface point, you should ensure that the shrinkwrap mesh is as close to the target mesh area as possible. In other words, you don't project in this mode, you just put one surface over the other as close as you can and then you ensure that when you move the surfaces, the meshes keep their relative distances as much as they can.

Here is a working example of this. actually it seems something pretty similar to what you want to do.

http://www.pasteall.org/blend/14055

Notice that the eyes are modelled over the sphere and that they are moved by bones which always maintain location and rotation of the eye objects aligned to the sphere object (target mesh). This way, it will never miss. Also notice that the result is even better when you subdivide the target mesh further with the subsurf modifier.

You can do very complex things with this mode, as I told you I have done several full body muscle simulation rigs.

See you!



> Date: Tue, 22 May 2012 00:53:12 +0200
> From: vicentecarro at gmail.com
> To: bf-committers at blender.org
> Subject: Re: [Bf-committers] Concept bug with	Shrinkwrap(projection)+armatures
> 
> Hi Pablo,
> 
> Thanks for your comments. However I'm not able to reach a usable 
> solution even with "nearest surface point". I've tried everything, 
> without succeed. If you want to try I've uploaded a simplified version 
> of the eye rig: http://www.pasteall.org/blend/14049 . The "target" bone 
> should keep the eye looking at it. Then you can scale bones 
> eyeball_internal and eyballe_external to change, independently, the size 
> of the iris and the pupil.
> 
> Anyway, I think we both agree the "project" mode for the Shrinkwrap 
> modifier is not working as expected and "using projection mode is not 
> such a good idea, it has many many problems with rigged meshes. ". So I 
> guess it should be fixed/improved/whatever. Is there a proper way to ask 
> for this fix? I mean apart of a bug report or posting the problem in 
> this mailing list ;)
> 
> And about the complex deformations " but what if the face of the monkey 
> was also deformed by other bones or shapekeys? ". I guess that is simply 
> impossible to do right now. Maybe in a few years...
> 
> Thanks,
> 
> Vicente
> 
> El 18/05/12 15:47, Juan Pablo Bouza escribió:
> > Hi Vicente!
> >
> > First of all I'm a blender user, not a blender coder :)
> >
> > I see your problem, and it seems a very difficult one...  For simple deformations the axis choice would work, but what if the face of the monkey was also deformed by other bones or shapekeys? In that case not even a change in the axis object would work, and it would require a kind of per face axis selection..
> >
> > But well, I've used shrink wrap for very complex situations, like flat eyes moving over the face of a cartoon character and also a complex human muscle systems. What I can tell you is that using projection mode is not such a good idea, it has many many problems with rigged meshes.
> >
> > The best technique I've found is using the "nearest surface point" mode, and then subividing the target surface mesh with a subsurf modifier. That way, the projected object will move smoothly over the the faces of the other mesh. This technique is 100% effective.
> >
> > I hope this helps!
> >   		 	   		
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