Hey there, I’m starting to texture a vehicle model for a game called MSTS (Microsoft Train Simualtor), the problem is that the .ace files which supports a variety of different modes, such as opaque or translucent images which are designed for different purposes.
the thing is, in order to get translucent images, I need to have 2 images, one is the actual texture, the other is a greyscale transparency image.
The opaque is normally used for the sides of the vehicle while the semi-transparent variants are used for windows and other translucent objects.
So if I’m modelling a vehicle, how do I separate the polygons which make up the windows onto a separate UV map compared to the rest of the body?
Notice in the video below how all of the redundant faces are put into a corner of the UV map and thus, not removed from the UV itsself?:
Considering it’s for a game, most likely you don’t need a separate UV map, the separate textures will be handled as separate materials. You just need to lay out the windows etc. on the same UV map the way you need them (hiding the rest of mesh parts can help to unclutter the UV editor). You can even test it out by assigning different materials to different mesh parts in Blender: all of them will be using the same UV layout, but distinct textures, so it wouldn’t matter that the UVs from the window parts overlap, say, the UVs of the hull.
Oh, how will this solution effect the size of the image? Since the windows are small and the hull is large and the UV placements have to make sense, it would mean that a lot of the UV space would be free if I was going to keep all of the UVs round about the same size.
You misunderstood me. Size of image doesn’t matter at all: you’re using full UV space for every mesh part that has its’ own distinct texture. The rest is handled by multiple materials. I don’t know exactly how it’d be done in the train simulator engine, but I’m attaching an illustration in the .blend file: it’s one mesh object, consisting of two mesh parts, each occupying the full UV layout. But the two parts have different materials assigned to them, so this overlapping does not matter at all.
Attachments
multiple_materials_one_uv_layer.blend (114 KB)
That’s a simple, yet ingenious way of doing it.
Thank you.