quote:Original post by SuperSpy
Don''t model the clothing as seperate objects. Just model any extra clothing geometry that sticks-out (coat tails, sleeve cuffs, flaired or baggy pant legs, skirts, etc.) right onto your base model... this will cut down on poly counts and prevent poke-thrus.

Give each peice of extra geometry it''s own unique surface material name, then you can switch these extra peices on and off in the game (depending on whether or not the particular character is wearing them). For any peice of clothing that doesn''t conform directly to the base character, you will need to rig with extra bones so it can be animated independently. As long as you animate the figure well, you shouldn''t run into any issues like Damocles was describing.

Hope this helps.

Basically:
The clothing should share the bones of the body except for the free swinging stuff which should have it''s own bones. Make sure the path of the free swinging stuff doesn''t violate the chracter''s space and you should be fine.

Right?

I''m still seeing somesort of collision detection needed to make sure when the leg is all the way back in the stride, the coat tail doesn''t intersect the leg. Could you possible make sure that the bone''s distance from the point is never less than the bounding ellipsoid? Otherwise, extrude the point (or control point) along the vector normal to the point and the bone to the desired radius. (If you find the distance using the dot product method, you can easily get a point on the bone to form the vector needed)

I think you would have to do the collision stuff on the CPU and pass the final rotation/bezier patch as a constant into the vertex shader...If you use a bezier patch type system, you should be able to reduce the number of points tested for collision (although with an increasingly difficult test unless the control points were very heavily weighted) by simply testing the control points, then using the patch to determine the positions of the verticies for the clothing on the GPU...

Thoughts?

quote:Original post by Anonymous Poster
Basically:
The clothing should share the bones of the body except for the free swinging stuff which should have it's own bones. Make sure the path of the free swinging stuff doesn't violate the chracter's space and you should be fine.

Right?

Exactly.

quote:I'm still seeing somesort of collision detection needed to make sure when the leg is all the way back in the stride, the coat tail doesn't intersect the leg.

Nope. If your leg intersects with the coat tail while you are animating the figure, simply adjust the coat-tail's bone and set a keyframe.

quote:I think you would have to do the collision stuff on the CPU and pass the final rotation/bezier patch as a constant into the vertex shader...If you use a bezier patch type system, you should be able to reduce the number of points tested for collision (although with an increasingly difficult test unless the control points were very heavily weighted) by simply testing the control points, then using the patch to determine the positions of the verticies for the clothing on the GPU...

Much less overhead to use the human eye to detect collisions and work this all out while the character is being animated.


[edited by - SuperSpy on September 14, 2002 5:34:42 PM]

quote:Original post by SuperSpy
Nope. If your leg intersects with the coat tail while you are animating the figure, simply adjust the coat-tail''s bone and set a keyframe.

I''m not an animator, but I seem to remember physics packages that are able to plugin to your animation tools and do some of the collision work for you.

Anybody else hear of these plugins (Havok?)?

quote:Original post by Anonymous Poster
I''m not an animator, but I seem to remember physics packages that are able to plugin to your animation tools and do some of the collision work for you.

If you''re going to use a vertex interpolation animation system in your game that would work fine. However, if you''re going use skeletal animation, then you need to program that kind of functionality into your game, not the animation tool.

Plug-ins for cloth-like clothing and collision detection are great for animating characters for computer animated movies where your are working with millions and millions of polygons, but for game characters--even if they''re 5,000 to 10,000 polygons--it''s really not that difficult to manage. Keeping a leg from intersecting a coat-tail is just as easy as keeping the right leg from intersecting the left leg... just don''t animate it to do so.

Keep it simple.