I have a transparency map for a grid. This map is on a texture support that is smaller than the grid. Outside the support's boundaries, the transparency map has no effect, this means I have a transparent shape inside a rectangle, and outside the rectangle, there is no transparency. But I want the grid to be all transparent outside if this rectangle.
I have tried to use a mix2colors but I can't get what I want.
How can I do this?
Thanks.
gs