Chris Huff wrote:

 >> 	It could, but that would mean recomputing the cloth at each
 >> render which  would be very slow.
 >
 > What about cloth simulation *requires* this? It could easily be kept
 >  as  a persistent object, like the particle_system patch, or have
 > data stored  in a temporary file, like radiosity or photon mapping.
 >
	This assumes you're doing an animation and want the cloth to evolve from 
frame to frame. I was speaking more of several test renders of the same 
scene for which having the cloth computed once ond for all is clearly 
better.

 > Again, why? A cloth object patch could easily convert to a mesh on
 > the  fly. No need to output a mesh to a file or restart POV. What
 > is different about cloth that it can't be done like height fields, 
bezier
 >  patches, or the particle_system?
	Unless I'm very much mistaken, you do recompute the particle_system for 
each render don't you? (I don't mean each frame in an animation here) 
This is too slow in my opinion, so you need to be able to perform the 
cloth simulation once and save the result in a file (a mesh is the most 
logical form of output here, though not the only one). Maybe the 
particle system renders faster than cloth, otherwise I would argue that 
particle systems should probably be implemented as an outside utility too...

	The ability to transform a bezier patch into a mesh is just a trick to 
make the render faster. The point isn't what internal structure pov uses 
to render a particular piece of data, but how the data is generated in 
the first place.

	I'll return the question about height-fields to you: what is the 
difference between hfs and cloth that would justify the cloth to be 
generated in pov while the hf is generated by an outside program? 
(Again, the fact that pov transforms the hf into something very similar 
to a mesh for rendering is irrelevant here, the point is that the data 
itself is generated by an outside utility).

		Jerome
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