We'll need to take a look at how 3d Models work to answer this question.
When a 3d Model is created, it is blank, to texture an object, we use something called a "UVW Map" a UVW map replaces the XYZ coordinates of the object itself, with UVW coordinates of a texture. The texture obviously is 2 dimensional, and the Object 3 Dimensional, at least to our eyes.
Once we apply a UVW map to an object, we then move the vertices of the object until we get the planes, or the flat surfaces of the object where we want them. Think of a 3d Model as a grid, and in the grid are many many points, these are called vertexes, the point at which 2 or more edges meet within a 3d Model, those edges then form 2d Planes, and from there the planes can be manipulated into a 3d Object.
Selecting each vertex one at a time, and moving them around, welding where needed, and deleting if necessary, we can take a 3d Object, basically Make it 2 Dimensional, and then apply it to the texture. This data is saved within the 3d Models export file as the objects UVW Map, or UVW Coordinates. BF1942 uses .SM to store this. Battlefield uses the .rs file to tell BF1942 what texture to use, and then maps whatever texture is told to those same UVW coordinates that are saved in the .sm file. If you were to put another texture on there, it is technically stretched over the model the same way, but the actual texture was fitted to the model.
Its all about taking something that looks 3 Dimensional to the human eye, IE: 3d Model and making it 2 Dimensional to the human eye. All things you see on the screen are 2 Dimensional, but we are able to trick our minds into believing we are interacting in a 3d World, but in fact everything you see is a 2 Dimensional object, just moved around, and given what in art we call "Perspective".
I suggest reading up on 3ds Max for more information. Just making a texture in photoshop will not work, texturing requires alot of time and effort inside a 3d Modeling program, to put the pieces together.
|