I am skinning some custom objects for the AvA maps. The objects were created in AC3D. I am creating my diffuse, alpha, and specular maps in Photoshop (latest version), from scratch. (Normal maps are essentially flat.) It is my understanding that the files need to ultimately be saved as 32 bit BMP's. To make future files easier to start, I set up template artboards for each version of the _N, _A, _S, etc. Each artboard template is 1024x1024 (or larger depending on the the type of object), 96 ppi, RGB Color 32-Bit, with the Working RGB color profile (sRGB IEC61966-2.1).
In order to get the artboards into 32 bit BMPs, I first saved the artboard to PSP format, then Export/Artboards_to_Files. I set the destination and filename, select "Include Overlapping Areas", "Include Background in Export", File Type BMP, 32-Bit, Include ICC Profile.
This seems to work. The end product is a 32 bit BMP, at 4 mb. Is this the way folks create the 32-bit BMPs? I am a total noob with this image stuff, and I don't want to spin my wheels in the dirt guessing.