Grass? It's not worth the time and headache to make it useable. Even if you blue screen it. The diffuse coloring isn't all that complex so you aren't saving any time there. So then its the arrangement of the grass that you're trying to save and at that point you can randomly generate the same patterns pretty quickly. Hair…
If your talking about how to actually render them so they look like grass instead of planes the key is to manipulate the vertex normals. Simply pointing them in a somewhat upward direction can help a lot but ideally you would also want to do something more fancy with shaders like diffusing the normals so they have less…
It depends a little on what software you are using to create the grass in and what app you will be displaying your final environment it. Generally I would model and texture a single blade grass, then use whatever modeling tools I have available to modify that original grass blade to produce some bent and broken variants.…