Chris Huff wrote:
 > [lots of thing about saving to a file]
	I see what you mean now. The problem with this approach is that it bloat
s 
pov with code that has nothing to do with its original purpose. POV is a 

rendering engine, it's meant to output images not cloth data, not 
particle system data, only images. Adding "features" like that inside 
pov itself can only result in overall slowdown (at least in the parsing 
stage) and harder to maintain code (and therefore, more risk of bugs and 

a longer wait between version). That's why I think those should be 
implemented as separate utilities (even if ideally they would reuse the 
pov code for object intersection. This isn't possible at the time being, 

both because of the license and because pov wasn't written for it, but I 

hope version 4 will address these points).

>> 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 mos
t 
>> logical form of output here, though not the only one).
> 
> But you can't continue the cloth simulation from mesh data...the most 
> logical output would be to save the whole cloth simulation. If it was a
n 
> external utility and you were producing an animation, you would have to
 
> output a lot of POV scenes and then render them, instead of running a 
> simulation while the animation progresses. If it is an internal patch, 

> it doesn't make sense to have it save to a POV file, because that means
 
> you will always have to run it from the very beginning.
> 
	If you look at the samples for the cloth simulator, you'll notice that i
t 
does run the simulation while the animation progresses.


> 
> 
>> Maybe the particle system renders faster than cloth, otherwise I 
>> would argue that particle systems should probably be implemented as 
>> an outside utility too...
> 
> And I don't see what rendering time has to do with any of this...it wil
l 
> render at the same speed whether you use a patch or an external utility
.
	If you allow the patch to write simulation related data to a file, then 

rendering time has very little to do with it. If you don't, a patch will 

have to recompute each time...

 
> Actually, it may be possible to optimize a patch for even more speed...

> 
	Actually, it *is* possible to optimize a separate utility for more speed
, 
since it may not need the same precision in the intersection 
computations that pov does (the cloth simulator certainly doesn't)...

		Jerome
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