Controlling Parameters with Mesh Vertex Colors 

 

Overview 

In addition to using guide channels you can use Maya's mesh vertex color sets to define parameter values which vary along the surface. This allows painting of parameters right on the surface. For example, you can paint where hair needs to be more dense or longer than other places.

 

Painting vertex colors 

Start by creating a new vertex color set on your mesh using these steps:

  1. Select the hair distribution surface (i.e. scalp mesh)
  2. Right click, select Color Sets, Color Set Editor... option
  3. In Color Set Manager window click New to create a color set
  4. Set Component Type to RGB
  5. Click Apply and Close to finish creating the color set
  6. In Maya's main menu select Mesh Display, Paint Vertex Color Tool
  7. Use the brush inside viewport to paint the vertex colors

 

Connecting vertex colors to a parameter 

Once you created your color set you can set it to control a parameter in Ornatrix.

  1. Select an Ornatrix operator inside operator stack, for example, Hair from Guides
  2. In Attribute Editor find the parameter which you want to control, for example Distribution
  3. Find a Channel drop down for the parameter, for example Distribution Channel
  4. Inside the drop down select the color set which you created

The color set should now act as a multiplier for the value which you are controlling, similar to a texture map. Vertex colors can be adjusted after they are assigned to a parameter and you should see the changes updated in real-time.