Just a fun little desert scene did for fun! 3k polys (including double faces for plants) (6)512s and (1)256 Some things still need to be tweaked but ohwell Wire:
Finished uvs and baking :) She has 3 texture sheets; a 1024, 512, and 256. I'll probably have to duplicate a lot of the hair pieces to make them look fuller.
How many rays are you using? For this large surfaces go to 512 or more, save 16-bit tga's and add a surface blur in photoshop to clean up any artifacts.
The texture size seams a bit high for the amount of detail you currently have and the amount of screen space the knife would ever use in a game. Would go for a 512 or 256.