ufoRasterSetPixelColApha sets the RGB-Alpha values in a pixel.
Values should be normalized in the range (0..1).
Depending on the raster type, the values set are as follows:
• Called on an RGB raster sets R=r, G=g, B=b
• Called on an A raster sets A = a
• Called on an RGBA raster sets R=r, G=g, B=b, A=a
Autodesk Softimage v7.5