"No...I gave it an opacity map...but no effect in game. Hm..."
The solution for this is a bit odd. IF you want to the opacity in the image then you must load the texture file into dbp and re-apply it. So if i remember correctly it should look like this:
load image texture.jpg,11
load object model.X, 1
texture object 1, 11
set object transparency 1
This is how the water in roswell racer was done.
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