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alexx
02-24-2003, 06:28 PM
heya,

just curious:
usually hiding a particle system prevents maya to calculate the system including collisions and all others..

now i have a really funny thing happening:
- i hide my particle system and all works fine (otherwise it would be hell slow since several 10.000 collide with objects).
- working in maya is fast as usual.. all normal.
- when i batchrender maya MAKES the particle calculation..
(the particles are hidden, the group they are under is hidden, the display layer they are in is hidden) - but nevertheless: they calculate..
but only on batchrender..

anyone knows this?

(disconnecting them from the "time" helped -> i would only like to know *why* this happens.. a bug?)

thanx and cheers

alexx
mark_wilkins
02-24-2003, 06:48 PM
Something -- somehow -- is hooked up to your particle object in such a way that Maya thinks there's a dependency. Maybe you have collisions set up with an object you're rendering, like a solid body? Maybe you have a shader that's hooked up to a particleSamplerInfo node?

The reason unhooking time helps is that it only calculates the state of your particle object once and uses that for all frames.

-- Mark
alexx
02-24-2003, 07:08 PM
thanx mark..
i just wanted to know why the particle system calculates.. not why the disconnection from time helps.. ;)

emm..
but still i dont see why it happens..

it is a system that i render with hardware rendering.. so no shaders with the particle sampler info.
all objects that are used for collision are hidden as well..

really tricky..
naja.. might be that i have a connection that i did by mistake and dont know it.. have to check that tomorrow back in work in hypershade..
really strange but thanx a lot anyway..
good points to start search from.

cheers & thanx

alexx

edit:
and there is still one thing that buggers me most:
if i would have a connection somewhere that would cause maya to calculate the particle system: why not in the GUI and only in batchrender? (exact same file, and in prefs "run up to current frame is disabled)
mark_wilkins
02-24-2003, 07:24 PM
Well, disconnecting from time gives you a workaround. You could always cache the particles once you decide to turn them on again...

-- Mark
alexx
02-24-2003, 07:34 PM
i think i will stick to the disconnection from time..
cause caching some 130.000 particles over 300 frames would kinda mess up my disk space :)

thanx & cheers

alexx
mark_wilkins
02-24-2003, 07:44 PM
Really? I can't imagine the cache would be more than a gigabyte or two.

-- Mark
alexx
02-24-2003, 07:46 PM
not sure about the size but i guess it would be some a gigs more.. and that with our network.. hehe.. better not :)
mattwood
02-25-2003, 09:42 AM
It's just an educated guess but I think Maya is calculating the particles because it is expecting that you might be turning visibility back on at some point during the render. There are many ways you could be doing this and not all of them are easy to detect beforehand.
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