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G.H.O.S.T
04-14-2010, 04:46 PM
I'm wondering if there is some trick to render thousands of particle instances on lowcost machine. In the scene are ~ 64.000 particle instances. The Object is low poly. I'm using mental ray for render. I get error that memory is low . Simulation is already cached.
I have 8 GB of RAM, i7 quadcore processor and Win7 x64 OS.

aghawa
04-15-2010, 12:22 AM
In the end, how many polys you end having in the scene?
Try using BSP2 in mentalray anyway, that could help. Or see if you can divide the render in multiple layers, for example foreground, midground and background, but i don't know how you could do that, sorry.

G.H.O.S.T
04-15-2010, 04:40 PM
aghawa
Thank you for reply. Yes, the reason was - high number of polygons ~60.000.000, almost 1000 per instance. I have reduced the number of polygons of source geometry. The thing I see very strange is that the Maya - software-render can handle this scene and MR no.

DDelapena
04-15-2010, 07:16 PM
Hmm..MR can't handle it huh? Weird.
Is the object something that can be a lot lower poly count? then you could use subDivide approximation on your object to still give it that smoothness without so many poly's. maybe that would help?

Not sure if there is a limit with MR or not...

I was trying to figure a way to break up the particles and render out several passes with different parts of the simulation...Since you don't want to re-cache. Wonder if there is a way to to show only specific particle ID's - hide the rest for now - and render them, then hide the others and show the other particle ID's - render those. Comp it together?

Aikiman
04-15-2010, 10:39 PM
I was trying to figure a way to break up the particles and render out several passes with different parts of the simulation...Since you don't want to re-cache. Wonder if there is a way to to show only specific particle ID's - hide the rest for now - and render them, then hide the others and show the other particle ID's - render those. Comp it together?

What you can do is base the opacity on the distance from the camera to the particle, that should work.

hkspowers
04-16-2010, 01:10 AM
I have seen scenes with billions of polys rendered in MR, so there must be a way. Might want to check the mental ray forum www.mymentalray.com to get some rendering guru advice. If Maya software can handle it then Mental Ray surely can, considering Maya software is no longer in development, nor has been for a while now.

shanega
04-19-2010, 10:42 PM
Use bsp2 and raytrace (not rasterizer) in your MR optinos. Also be sure to delete any history and remove any grouping on your instanced mesh before rendering, at least in my case this could make my render explode. If you do it right (and use a newer version of MR) you should be able to render hundreds of thousands of instances very quickly for the cost of a single mesh.

Shane

G.H.O.S.T
04-20-2010, 08:01 AM
Thank you guys ! Yes, after optimizing all that stuff - polygon number, BSP2 and changing scanline to raytrace renderer was realy helpfull. Now I can render this scene realy fast with MR.
About 6 - 8 minutes per frame large resolution.

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