how do you apply AO to objects with tileable textures?
polycounter lvl 5
Hello,
I have an object with tileable textures, which its texture coordinates are out of the 0-1 space. That means I can neither bake an ambient occlusion map nor a normal map.
At the moment I just threw the regular diffuse map into crazybump and baked out my normalmap there... but what can I do to have AO for the whole object, without having a map?
Hope someone can help me out.
Cheers, Andr
I have an object with tileable textures, which its texture coordinates are out of the 0-1 space. That means I can neither bake an ambient occlusion map nor a normal map.
At the moment I just threw the regular diffuse map into crazybump and baked out my normalmap there... but what can I do to have AO for the whole object, without having a map?
Hope someone can help me out.
Cheers, Andr
Replies
Depends on your engine, but if this is allowed beware that it pretty much duplicates your verticies.
It adds less than you think - does depend on the context though. Most AAA-level artwork has a lot of data saved in the verts already, adding another UV channel is comparatively not as much of a performance cost as you would think - in that scenario.
very simple:
assuming youre using MR as a render engine,set your dropdown menu to "Rendering"(Yellow dots),then in the Lighting/Shading menu (Green dots)
select Batch bake(mental ray),go to the options of it.Next set your options in this dialog eitther to texture or verts and bake.you can play around with the different options here to suit your needs..
Then after you baked it it appears as ao only on the object,to mix it with the diffuse and other maps,go back to your Polygon menuset(Yellow dots) and then go to Color-->Color material channel,and then choose Ambient+Diffuse.
Much Appreciated!
I tried it with the radiosity. The results are not too satisfying. Also it seems that the 3point shader lite I am using is not displaying the vertex paint in the viewport.
Anyway, maybe I will try it with two UV-layouts. Do you guys have a quick explanation how I set up two UV-Layouts? Does the CryEngine support 2 UV-Layouts?
The solution of tiling the texture itself more would work if the uv-layout wasn't so widely spread.
Here's a pic of the object and its uv-layout:
Thank you for your help!
What do you mean by this Ace? AO isnt directional.
link?
http://advances.realtimerendering.com/s2010/Hable-Uncharted2(SIGGRAPH%202010%20Advanced%20RealTime%20Rendering%20Course).pptx
Basically, what Cyrid said, the AO map should 'appear' in the shadow-ed part of mesh, while anything hitting with direct light should be washed out, true values, bleached, etc whatever you want to do, but shouldn't have hard shadows/ambient.
Is it 100% correct? Nope, but we're still ages away from having pixel level AO from the Normal map as opposed to just vertex/general shape, and other then Fight Club, I don't think I have seen any other game engine do proper AO in self-shadowed models.
Afaik AO and diffuse/specular lighting are done in seperate passes, so there is no way to remove AO from an area by using directional lights. You can only "hide" it.
edit: just adding on to that: If you do what has been suggested here in the thread and bake the AO in the vertex colors, then the diffuse color of the model will be darker, and it wont be able to be cancelled out anymore (since even though AO and directional lights are different things, they are both still lights).
i tried to do import it from 3ds max to udk and the shading didn't stick
you mask your indirect light with it. then add that to your direct. Its in no way directional or related to your scene lights. Theres nothing physical about AO though its just a fake to help simulate GI, so i guess you can use it like you want. Also far be it from me to critique the guys at naughty dog. they know their shit (i cant read powerpoint docs, so i cant comment on what they're doing.)
If you import it as a FBX it should bring the vertex colours in. Make sure you have replace vertex colours turned on.
http://udn.epicgames.com/Three/FBXImporterUserGuide.html
Then you just have to setup a shader with the vertex colour multiplied over the top of the diffuse.