monumental slowdown

[vectormodeling]

for most of my exterior renders, i have been using simple geometry to create grass rather than displacement. i prefer doing this because it allows the grass to be aligned in directions other than straight up, which is the only option with displacement.

 

generally, a blade of grass is 3 triangles, the scene contains ~500,000 blades, totalling ~1.5 mil triangles. maxwell has no problem rendering this.

 

however, as soon as i introduce some instanced trees into the scene, the render speed plummets. it is very odd, because i can render either the heavy geo grass or the instanced trees. both of those will render fine seperately, but when i try to render them both in the same scene, the maxwell benchmark plummets from ~20 for either scene by itself, to ~0.8 for the grass w/ trees.

 

i'm wondering if anyone has had any similar issues. the only way i've found to resolve this is to use displacement grass any time i want to use trees/plants in a scene.

 

attached are some images showing the renders seperately, and together. sorry for the red default mat on the trees w/ grass_geo image, but it just reiterates my point that even with a single material for the entire scene, maxwell can't render heavy geo grass w/ heavy geo trees. very confusing.

 

thanks.

[Tommy L]

Its a ram issue. What OS do you use? and how much ram do you have in your machine?

If you have xp pro 32 bit then is the 3gb switch enabled?

 

You can either optimize your scene to accomodate the fact that you are currently running out of available memory resources or address your ram shortage.

 

I would recommend running xp 64 and buying more ram.

[vectormodeling]

i don't think it is though. i'm using os x w/ 3gb of ram. when rendering the scene w/ trees and geo_grass, ram usage only goes up to ~500mb. its just the render speed the dives.

[Tommy L]

hmmm, i dont know then. I dont use maxwell. But the logic is telling me its ram related. Have you tried with just one tree? Half a tree?