Normal Map Question

Support Modeling
1

Hello,

My small indie team is making a game on the Unity engine and there is a topic that I am a bit confused about.

Normal Maps, now I fully understand what they are and how to make them/bake them etc.

The part I am not too sure on is once I bake a normal map and Unity only has ONE normal map texture slot… how do game developers bump the diffuse textures once you have a normal map in place to get the low poly version up to looking like the High Poly that you baked the normal off of? I hope that made sense :slight_smile:

Is there a procedure for blending a diffuse normal map with the baked normals?

I currently own the Substance Designer 4.1 and thinking that may be my solution to perhaps blend the normals (if that’s what you do blend them)… I’m at work now but would love to hear how other people handle this? Maybe I am missing something in the process.

2

One way is to use image editor- "overlay for red/green channel, multiply for blue channel then merge them.

3

You claim to fully understand normal maps, I think you don’t.

The diffuse texture affects the color in the render pipeline.
You assign the diffuse texture as is.

Then you assign the normal map as is.
The normal map holds RGB values for each texel. Those represent the XYZ components of the normal vector for this texel.

Now the texture information is processed in the rendering pipeline. The texel information of the diffuse map is used to give the pixel on the screen its color, and the texel information of the normal map is used to “bend” the normal, affecting lighting. It’s fake geometry so to say.
Without specularity a standard normal map pretty much is not noticeable.

4

I’m going to hijack this post with a question because I think it’ll help the op in some regard… though maybe not.

With Unity, how does one get the “fake geometry” effect without specularity? I love me some good normal maps, but then everything always looks wet/glossy.

EDIT: And by help I mean help with normal map stuff… obviously not their exact question.

5

how does one get the “fake geometry” effect without specularity? I love me some good normal maps, but then everything always looks wet/glossy.

Like arexma wrote a normal map it is not very much noticeable without specular. For that you can look into displacement mapping

@Tantrumus

it is called normap map blending you will find very good reference on the polycount wiki

6

Thanks but I think you misunderstood my explaination. When I use a product that creates a normal map off a diffuse texture like “Crazybump” “NDo2” or “Bitmap2Material” (all of these create normals off a diffuse texture for you) my question was how do I combine that normal map based off the diffuse texture details with the baked normal I produced with a product like XNOrmal for example.

I appreciate all the responses… I ended up finding my solution with Substance. There was a Normal Map Combine node which let me generate a single blended normal to use in the single slot allocated for a normal map in Unity.

Thanks.

7

This is actually easy. Change the color of the specular to black or darker and then you don’t end up with the wet look. I battled with that while myself.

8

My other responses are awaiting moderation, @jsmith the type you are after I believe is “bumped diffuse” in Unity.

That will give you a diffuse, and normal texture slot.

9

Sorry for all the spam in this thread, @Polygonaut, tyvm for that link, this is great information.

10

Ah. Yes I have indeed.
“How do I combine 2 separate normal maps into one normal map?” would have done it :wink:

You can simply blend the normal maps in any image manipulation tool, like GIMP.

  1. Open first normal map.
  2. Load second normal map (open as layer)
  3. Set blend of the second layer to “grain merge”
  4. Save new normal map.