Vertex colors are often used to simulate lighting. Polygon Cruncher is able to keep this information during the optimization process.

When needed, it's possible to protect frontiers between different colors (freeze vertex colors discontinuities) by frozen points that belong to these frontiers. A tolerance factor set the level for which a vertex color is considered to be different than its neighbor colors.

Look at the visual example for more information.

Freeze vertex colors discontinuities

This option freezes automatically points:

• Which are on the frontier of different colors (points which have several colors).
• Which have a color discontinuity with their neighborhood.
  RGB tolerance allows you to increase or decrease tolerance on colors discontinuities.

Enter a value between 0 and 255 to increase or decrease the color discontinuity threshold.

• 0 freezes all points which have a different color than her neighbor.
• 255 does not freeze any points.
• 20 is, generally, a good value that allows to keep colors frontiers without reducing excessively the optimizable points or faces numbers.