Normal Map Creation

A normal map should be created in the same dimensions as the image texture (color map) it will go with. There are a few options for how to create one, depending on the quality you want, your skill with various programs, or your patience.

Normal Map from a Heightmap

As the Source tool Height2Normal doesn't work anymore, you will have to resort to other tools in order to convert a heightmap to a normal map.

Todo: Which ones?

Normal Map from an image editing program

• Photoshop or Paint Shop Pro
• The GIMP

Normal Map from a 3D program

• XSI
• ZBrush2
• Lightwave
• 3D Studio Max
• Maya

• NVIDIA Melody
• NormalMapper

XSI

• ver 5.0: Ultimapper
• ver 4.x: GPU Surface FX2
  Note:You need XSI foundation or higher to take advantage of this feature, as the Mod Tool has a resolution limit.
• ver 3.5: GPU surface FX

The name has been changing, but the basic usage is the same:

• Move the high resolution model over the low resolution model.
• Select the low resolution one.
• Select GPU Surface FX2 (or Ultimapper in ver 5.0) from Get>Property.
• In GPU Surface FX2 menu:
  • Pick the high resolution model (or group).
  • Make sure normal is checked.
  • Change settings such as normal map resolution, path, sampling, as you want.
  • If you are ready, click Regenerate button. XSI will make the normal map.
  • To preview the result, set Preview Display and Hardware correctly and click Create Preview.
  • Important: It is necessary to invert the green channel of the output file. If you don't do this, your up/down normals will appear inverted in the engine. The simplest way to do this in Photoshop is to open a channel window, (window:channel) select the green channel (which controls up/down), and press Ctrl+I.

Getting the Normal Map in the Game

1. Save your normal map as a TGA in the same resolution as the original texture. Give it a name that ends in _normal. Then convert it to a VTF. The _normal at the end of the name will affect how Vtex converts it. For the brick wall example, we would name the file brickwall_normal.tga. Place the new VTF in the same place as your original texture.
2. Add this line to the VMT somewhere between the braces:
   

   "$bumpmap" "texture name"

   and fill in the path and name of your normal map VTF. Here's an example VMT for a normal-mapped material:

   "LightmappedGeneric"
   {
       "$basetexture" "walls/brickwall"
       "$surfaceprop" "brick"
       "$bumpmap" "walls/brickwall_normal"
   }

   Note:Multiple materials can use the same normal map file.
3. When compiling your maps with vtex, Add this line to the <texture filename>.txt file in the same directory as your textures then compile with vtex.
   

   "nocompress" "1"
   "normal" "1"

See Also

• Creating Materials