Drawing Without Accumulating Opacity

[barbq]

Hi,

I'm using the artUserPaint context customized tool. I use this tool to paint geometry (similar to the supplied "Paint Scripts Tool").
I came across the problem that once the user has painted some geometry on the surface, the "opacity" of the painting is then stored and the user cannot draw further geometry in that area, unless he removed the existing painting.

In theory, I should replace the drawn opacity with the new one, but it's not very practical for my uses.

Any idea on how to use the context but make it ignore the current opacity?

Thanks