void setColorsUsingColorBlend()
{
int size = colorBlend.Positions.Length;
shadingColors = new float[size][];
positions = colorBlend.Positions;
float[] cgColor;
for (int s = 0; s < size; s++)
{
cgColor = colorBlend.Colors[s].ElementsCGRGBA();
//Console.WriteLine("shadingIndex {0} position {1} factor {2}",s, positions[s], factor);
shadingColors[s] = new float[4];
for (int c = 0; c < 4; c++)
{
shadingColors[s][c] = cgColor[c];
}
}
}