fx Texture Format

[DaiG]

Photoshop / Irfanview / quite a few other graphics programs show the effects texture files (p3d\effects\textures) to be 24 bit with an alpha channel. However, whenever I load an existing texture file into Photoshop, modify it and save it as 24 bit with alpha, it shows up in-sim as the good old square blocks, implying that the alpha channel is missing. The alpha channel is there (can see it on reloading the bitmap) and the black in the RGB channels is 0,0,0 (pure black) as specified in the SDK. I'm using Blend Mode = 2 in the .fx file. I did try the other Bland Modes but the effect either didn't show up (Blend Modes 0 and 1) or appeared as dark square blocks (Blend Mode = 3). Has anyone any idea how or what I am saving incorrectly?

[DaiG]

The answer to this one is to export the texture file as .dds with alpha (BC3) and not as a 24-bit bitmap with alpha channel. It appears that Photoshop does not export the 24-bit bmp with alpha in a format that P3D recognises. Using a .dds file also seems to give finer control over the alpha in the finished texture file.