surfacing

Improved dirt maps by Xuan Prada

When we start the task of texturing props, environments or characters, one of the first steps we accomplish after completing the UV Mapping, is baking different texture maps or procedural maps (or any other type) to a later use them as a base point to paint our textures.
Probably the most baked map is the ambient occlusion, to reach a base of dirt in logic areas which we will modify in Photohop, BodyPaint or Mudbox.

In my own experience I think that occlusion bakes are incredibly useful but a little bit boring.
Find below a simple method to create a more funny and live ambient occlusion bakes.

  • Using a costant shader or any other which are not affected by lighting, we mix using mix2colors, blendColors or Mixer.
  • In the channel 1 of the mix we use a map. Can be procedural or bitmap. In this example I’m using a tiled bitmap.
  • In the channel 2 of the mix we use a white color.
  • In the mask of the mix we use an ambient occlusion.

With this method we achieve that the bitmaps or procedural maps get masked by the occlusion, creating dirt on the logical and less exposed areas, but with the variation given by the map.
The keys to reach good results are the configuration of the occlusion and the quality of the maps.

This is the scene that I'm using for this example.

Regular ambient occlusion render.

Ambient occlusion render mixed with bitmap textures.

Dirt shader in Softimage.

Dirt shader in Maya.

Dirt shader in Max part 1/2

Dirt shader in Max part 2/2