Normal Maps and Lightmaps, are they worth having?

Graphics Lighting & Global Illumination
1

Hi!

If I have a level made up of lightmaps and very limited Realtime lighting is there any point having normal maps? Seen as there is no RNM within the engine I can’t seem to see the point? When I look at my scene I can’t see the normal maps at all.

Whats anyone elses thoughts?

Cheers.

P.S. I tried to bake the normal map details into the lightmap using Turtle, no sucess.

2

without realtime pixel lights, normal maps are worthless unless you write special shader to handle it.

3

Someone could write a radiosity normal map shader (we really should have that included), but until then, yes, if you don’t have any pixel lighting in your scene then using normal maps is pointless.

4

Thats an intense shader to write! I can’t imagine even the BEST coder could write that quickly.

/the gauntlets been thrown down :smile:

5

What do you mean by a radiosity normal map shader? Normal maps don’t mean anything without pixel lighting, just like vertex normals don’t mean anything without dynamic lighting. If you’re not doing radiosity in real-time (which you aren’t), any effect of normal maps can be baked into the light map.

6

I think what he means in this case potentially might be an alternative (compared to normal) special way of lightmapping.

There are at least 2 types of lightmapping:

  1. The plain “dumb” color baking lightmapping used in the majority of all engiens

  2. (not fully sure on that, haven’t touched a tech with such capabilities for a long time so I might be off on the details)
    The normal based lightmapping where you store the normal color for each color component, not just an 8bit diffuse. That means not 8bit per channel in the end but 24/32bit.
    As unity doesn’t support floating point textures right now, you would use 3 / 4 lightmaps, each encoding the lightmap normal data of an own color channel
    If you then use this lightmaps, you actually get lightmap data that:

  3. allow normalmaps to work without light

  4. allow lights to interact with lightmaps too

7

Ah, Ok. I just found the paper. I’ll read it when I get a chance.

8

I think that would be a fantastic addition to Unity (not only for the users but also as another notch on Unity’s belt :slight_smile: )

The only problem I see is that there isnt a good solution out there to create the radiosity normal maps to begin with (a Google search only turned up a plugin for Maya users … which isnt good for non-Maya users like myself) … unless it was built into Unity so everyone could use it.

But it definitely would be great to see the fantastic visuals that would be created by Unity users.