I've been learning Blender and have made some decent progress. I've made some neat models, but so far, they haven't been textured. I understand how to unwrap a model so as to get the UV coordinates, but how do I actually create a texture to fit this coordinates? I've looked around and so far, it seems like a lot of people spend time hand-painting their models. Then I look at games like Counterstrike: Source, Call of Duty, etc., and I'm wondering how their models look photorealistic. It's all a bit of a mystery to me, but I'm hoping somebody could clarify. So, how exactly are photorealistic models created?
I can picture three common routes for creating a photo-realistic texture. Either:
You're a talented artist who can paint photo-realism and has no problem making it from scratch.
You use a camera to take a photo of a surface that looks similar to what you need.
You have enough artistic skills to start from a photo and modify it.
But that's concerning textures only.
As for the factors that contribute most to the overall photo-realistic look of a scene - besides having great assets - I'd boil it down to lighting and detail (links for reference, not as definition, but worth reading).
Game makers use something called bump mapping and normal mapping.. You can create those in a program called awesome bump, and then add some ambience and occlusion. It helps if you darken your areas in your texturing. In blender, you can now use nodes in cycles render to create edge wear with a new feature in the geometry node called pointiness.. This is to be used with color ramps, two or more then input the color into the factor of a mix shader, you can then use glossy and diffuse / PBR shaders, your choice :)
textures are just a layer drawn on top of the object. which is technically called
texture map. most games usually use other maps such as
reflection map, ... which makes objects rendering more realistic. and there are some applications like ZBrush which allow user to paint over 3D objects instead of working on a 2D texture.