Mathematica: Opacity and graphics

[Niles]

Hi

I have the following graphic:

Graphics[{Opacity[0.5], Rectangle[{0, 0}, {1, 3}]}]

Say I want opacity to vary with x, e.g. with the expression opacity = x^2. Is there a way to do this? I checked out the "Help", but there were no examples of a varying opacity.


Niles.

 

[Dale]

Use Raster instead of Rectangle:

Graphics[Raster[Table[{0, 0, 0, x/128}, {x, 128}, {256}]]]

The elements of the Raster are {red, green, blue, opacity}.

 

[Niles]

Thanks, it is kind of you to help me.Niles.