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Old March 16th, 2008   #1 (permalink)
vectormodeling
Junior Member
 
Join Date: Apr 2006
Location: Vancouver, BC
Posts: 5

Name: Nathan Todd-Stone


Canada 


Default monumental slowdown

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.
Attached Images
File Type: jpg a.jpg (132.5 KB, 47 views)
File Type: jpg b.jpg (192.3 KB, 60 views)
File Type: jpg c.jpg (263.0 KB, 47 views)
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