Grass displacement is so slow (Vray for Rhino)

Hello,

last I made a test for grass with displacement. I ask me, are my render times typical or is something wrong here? For this test I used a Q6600@3GHz.

How to create grass per displacement is discussed at the Vray for Rhino forum here at the moment:

Ciao,
Micha

Try playing around with your AA settings..

I think, best I post the general settings of the scene. Should I change something here? I use XP64 and 8GB RAM - maybe I could allow Vray to use more RAM. Could it be done per “Mem Limit”?

I suppose it is because in Rhino we only have 3d displacement; in 3ds Max one can use the 2D displacement method, which is faster.

Best regards,
Vlado

how much faster would you say a 2d displacement is vs 3d?

It depends on the settings, of course, but for grass, where you need lots of fine details, it can be substantially faster, as it will take less RAM if the map is tiled.

Best regards,
Vlado

what if one was to have say…5 high frequency detail 4k maps in displacement…would they still be faster to render with 2d vs 3d?

No idea… it should be tested to see which one performs better.

Best regards,
Vlado

if you have ram to spare, raise the dynamic memory limit, and you’ll avoid the swapping of displaced geometry from ram.
400 megs seem way too low for that kind of detail, to me.