Making Night Textures using Corel Photopaint
Open the base day texture.
Click on Object, then Create, then From Background.
Click on Object again and select Duplicate.
Mask off areas that you want to show at night, the windows in this case.
Once you have the areas masked off that you want to show at night be sure you have the top object selected and click on Cut.
Now click on Effects, then Render, then Lighting Effects.
Position the light beam and adjust to your liking.
Once you have it the way you want it click OK. Set the object to Multiply.
Then flatten the image.
If you are doing an area without light splash, or making an alpha mask for FS2002 just turn off the light and click OK.
Before you flatten and save it as the night base bmp, copy the object to the clipboard.
Now click on file and select New From Clipboard.
Flatten the new image then Invert it.
Save it as the alpha bmp to import into DXTbmp as the alpha channel for the night texture.
The alpha is the same wheather you have the light splash or not.