I'm using OpenGL ES + GLKit. I've never been this low-level before in my life so I still have to learn a lot of things. I've developed a Unity games before and you just give it a .obj file and corresponding texture and it's done. (UV mapping happens to be inside the .obj file?)
I want to develop a kind of special Toon Shader with some different characteristics for use with 3D model. So I need to write a vertex shader (.vsh) and fragment shader (.fsh) right?
However, I just know that in order to apply a texture to a model with correct UV coordinate, you have to do this in shader? (am I right?) With "Texture Shader".
So, If I want to both apply the texture with UV mapping then apply my special Toon Shader, I have to write both in the same shader? There is no way I can create a plug-and-play Toon shader so I can use it with anything?
As a side question, which file format is a UV coordinate and how can I take that in to a shader program? What kind of attribute variable?