AO Across an Entire Environment.
polycounter lvl 18
I've got an old PSP res environment that I want to spruce up a bit for my portfolio. It's textured with loads of different textures, most of which are tiling. I'd like to do an ambient occlusion pass but this is proving to be a little more complicated than expected in Maya.
After going through loads of tutorials, none of which cover the final couple of key steps, I've gotten as far as making a new uv channel, doing a quick unwrap of the entire environment on to it and baking the AO map. What's my next step?
After going through loads of tutorials, none of which cover the final couple of key steps, I've gotten as far as making a new uv channel, doing a quick unwrap of the entire environment on to it and baking the AO map. What's my next step?
Replies
1. Save your scene as a new file to avoid losing any data.
2. Set your renderer to mental ray.
3. Set the background color to white and the global light to zero (everything is black).
4. select all the objects and give them a standard material, set it's color to white.
5. place an ambient/occlusion map in the self-ilumination slot (more samples for higher quality).
6. delete all the lights in your scene (they are unnecessary for this)
7. render.
8. multiply this map over your standard render in photoshop
I dont know what app you're using, but it should be fairly simple:
1, make 2nd uv set for all of your objects(prefably one big image for everything
2, bake the ao map
3, use a shader/material that multiplies that result onto your texture
After all these objects are textured individually as I mention above, these objects are then combined or attached into a large super environment object (?) in order to bake out the AO on a different channel for the whole environment(?). How is this AO map applied in game when all these pieces are again seperately( i assume?) taken into a game engine with their own specific diffuse / normal / spec maps? I realize those maps are on a different channel but the AO was baked onto UV islands of the single attached super object so i dont understand how that map moves backwards to the previous seperated objects in the whole scene...
I guess my question is: Once the environment is combined into one object in order to bake the AO will it from then on have to remain a single object? If not, how is this AO normally dealt with in the engine specifically?
If this is an asset for a game, you NEVER add it in post. If all you need is a render then yeah, you dont need to do anything more than post, but really if you want something that looks correct from any angle, and is actually close to what you would do in a production environment, using a 2nd uv slot is best.
Short answer: It depends heavily on the engine/workflow/whathaveyou.
Long answer:
Some engines (like UE3) will automate some of this process for you, all you need to make sure is that your model has a 2nd uv channel for the LM, and probabbly something with the materials that tell it to generate, and display the LM.
As far as combining everything onto one uv set, this is entirely up to you/the specs of your engine/project etc. Generally you would group things that go together into one image. Say you have a building built up of multiple materials, you would probabbly want to have this entire object share one lightmap, so you can easily make adjustments to the entire thing.
here are your 2 solutions:
for verts
- go to color>batch bake (mental ray)
- set it from bake to: texture to bake to: vertex
- change color mode to occlusion (tweak the other values if needed)
- hit convert ( or convert and close)
- right click your model choose color sets>color set editor
- up in the menu go to display > selected > color channel material ambient + defuse
DONE low fidelity but guaranteed to be psp compatible, artifact free, no need to uv map anything extra or fiddle with materials and its cheap.
for light map ao ( i assume you already have your uv set and ao texture as you posted)
-go into the material editor
- choose every material one by one and hook your ao texture into the ambient slot
-right click you model choose uv sets > uv linking
-on the left side select your second UNIQUE uv map and at the same time highlight all the ao textures that are listed on the right
-set render mode to HIGH QUALITY in your preferred view port
DONE higher fidelity but might make other light setups in your scene look wrong, requires extra uv work, might not be compatible with your psp engine, might have artifacts, can not be previewed without high quality render mode.
This would likely be either automated, or script-assisted in most studios. We were doing a lot of this sort of thing the last place I worked and had a MEL script that would let you select a bunch of discreet objects and try different automatic unwraps on a second uv set that it created for you, no combining required. Without something nice like that, we're stuck with the old-fashioned way.
NO post in game enviros unless it's a static render, if it's full 3d, bake all the way to second uvs or vertexcolors.
EDIT: Its not PSP though lol
What software are you specifically referring to here?
It's hard to say exactly which way to go for all hardware, so its good that everyone turned out in force to explain a few different ways. Nice going guys, you're all right!