Learn the difference between Gouraud Shading and Phong Shading.
Find out how OpenGL deals with texture coordinates which fall out of range and how it deals with texels that do not have a 1 to 1 correspondence with pixels.
Understanding how textures work in OpenGL can be confusing. Especially for someone new to OpenGL. I Hope that this brief introduction to OpenGL textures can help you.
Do you know the purpose of a Vertex Attribute in your OpenGL program? Learn why they are so important and how they are used within shaders.