Baking overlapping transparent surfaces in 3DS Max

JamesWild

Hello! I'm trying to make a game environment run better (mostly not my stuff) and I'm trying to bake a bunch of quite similar bush models to far simpler models. Basically, the artist who made them made 4 quite high poly spheres, applied noise and gave each one a different tiling leaf texture (with all different colours/etc.) and I'm trying to bake this to a much simpler piece of geometry so it isn't 5ktris (10ktris+ for the hanging baskets). Problem I've encountered is that 3DS Max's render to texture seems to capture either the first or last surface it sees (changeable via a radio button) and ignores all the rest meaning it doesn't capture the layers poking through one another, just the top or bottom layer. This means that when I view the resultant texture, it's basically a cylinder of floating leaves.

I really don't have time to be doing all these models again, (got to be scripting and doing other level optimisations to try and get a playable framerate) and as I've already low polied and unwrapped them I don't want to waste the time doing that either.

Any ideas on making Max's Render to Texture capture all of the layers? Thanks.

Max viewport render:


Baked:

St.Sabath

Might be an idea to transfer part of it to a 2nd uv set and bake out the sets seperatly,depending on how the layout looks that is.So for instance if you can select all faces that overlap to a 2nd UVset,then bake out set 1 and set 2 seperatly,can you post a snap shot of the current uv's,with the overlapped faces selected?

JamesWild

The UVs aren't overlapping. It's four noised spheres with separate opacity maps and a cylinderical unwrap for the high poly and a planar/break edges/relax for the low poly. My issue is that when it does a raycast to get the bake colour at that point it returns the surface colour of the high poly rather than sampling all four and using the alpha to blend. I don't understand what you mean about 2 UV sets or how that'd help, sorry.

St.Sabath

sorry i misunderstood,i thought you had overlapping faces in your model that made it impossible to bake out as a whole.
Is it possible to bake them per sphere and comp in PS?

JamesWild

Blender does the exact same thing.

Just ended up baking all four layers separately and using a render clouds alpha in Photoshop to add variation. Time is short.

Thanks for trying to help.

St.Sabath

no worries m8,keep on pushing,you'll get it done no doubt! :thumbup:

Eric Chadwick

Another technique here, for future reference
http://wiki.polycount.com/NormalMap#Baking_Transparency

JamesWild

I understand how that works but I'm not quite sure how it helps in this context? It's not say a flat floor tile nor am I baking normal maps for this, I'm just transferring the fairly complex high poly diffuse to a lower poly diffuse. (it doesn't have normal maps)

Thanks again though.

Eric Chadwick

The texture is not very specific in your source art. I would simply map the source to some overlapping flat planes, and bake it into a reusable tiling texture. Better yet though, I would recreate the art completely because it's not very bush-like in the first place.