posted this on the unity forum but not sure what to expect for a response (long story) so I thought I'd post over here since there seem to be more than a couple of friendly and knowledgeable people about I am googling for help for awhile now but already realizing that there's no easy super-noob friendly answers for the solutions I seek (although these issues aren't particularly complex) I am seeking a solution in unity where I can assign a simple solid color to be semi-transparently laid over a texture. Say I have a generic "cement" texture, and I want to apply it all over the place on different objects to save tex memory, but run a color filter over it to make it appear varied. In some cases just use it for cement - then slap a blue filter over it for a park bench seat - a red texture for some trim on a bldg, etc. It looks like there may be a few ways to do this, not sure which is best. I am hoping to avoid an instance where i have to get code-y with it (though looks like such things are probably normal in unity) Ideally I want to find a solution where I can effectively "additive Color" over it and still be able to do vertex lighting on top of that, if I am going to bake lights that way. Also, curious what people's thoughts are regarding best lighting solution for an mobile app with speedy-framerate requirements. Baked lightmaps look very nice of course, but that's adding a bunch of tex memory which could probably be better spent elsewhere (or sacrifice altogether for framerate actually). again I am thinking baking vertex lights, and cutting shadows into geometry/making floaters like in the PS2 days. And in all of these cases, I realize that unity will still have to do another pass on the geo for as many x filters as are applied, as opposed to unique textures, so I am curious if that's a (general) significant performance hit one way (drawing geo) vs the other way (loading more textures into memory, but drawing less geo) thanks for your help!
Seems like the best way to go is to use a "Diffuse Detail" shader. The main texture slot is filled with a moderately low resolution color texture, to define the object's shape/color, while the second slot gets a tiled texture to look decent on the close-ups. The main color texture is multiplied by the detail texture. I think it would require some modification if you want to bake the lighting to vertices. I don't know your specific case, but I myself have a really bad experience with vertex baking and geometry shadows (low flexibility + high time consumption in creating/modifying assets). The lightmaps in Unity are working pretty good, so maybe that's worth some in-depth checking out. Another thing - when are you due to release the game? Maybe the low-memory devices will be obsolete by then? Now, as for the drawing of the geometry - I've run a 100k polygon scene on iPad 1 with steady 30 fps (not all scene visible at once). Newer devices can do much better, so the vertex count isn't really a problem. At least as long as the geometry is drawn once - meaning no transparencies, no blending, per-pixel specular/normal maps in the shaders, etc. You can, of course, use these things but keep in mind that's the bottleneck od the mobile devices. Two textures blended in a diffuse shader are no biggie, though.
