Rendering normal map information to lightmaps

Unity Engine
1

I was looking at the UDK app Epic Citadel and it seems like they are baking their normal map shadow information to their light-maps, as the lighting is static in the scene they don’t have to render normal maps at run time but still get lovely bumped effects baked in.

Is this possible with Unity? Has any one managed to get this up and running? I was looking at the advanced Beast settings but could not see any setting for taking normal map information into account when rendering light-maps. If I can bake normal map shadow information into light-maps and at runtime only calculate specularity I think I could achieve a very hi-end looking game on ipad2/3.

2

That’s a clever idea. =)

I got it up and running - you need the “directional lightmaps” bake and then you create a shader that does the object space to tangent space transform. Msg me for more details.

3

Not the same thing. Directional lightmaps require you to keep your normal maps. What he is talking about is having the lightmapper actually use the normal maps when it does its light calculations. Beast supports this, but Unity won’t feed it the necessary information.

4

As in the normals baked into the light information, or the normals just influencing the bounce?

Those would be some huge lightmaps otherwise!

5

The normals baked into the lightmap texture, you can do it in UDK, it looks great on the citadel demo.

6

Hi, Unity 4 does this, if you have a normal mapped shader and render lightmaps in forward mode it now bakes the normal lighting into the lightmaps! Ace.

7

Does this work in Deferred Rendering?