Hello, I''m starting work on a terrain engine, based on a 2D array of hieght values. Anyways, I was wondering if it''s worth it to make sure every quad is flat. I mean it would make some things easier such as determining the hight at a point between quads, or sending less vertices to the renderer. But, then I would somehow have to make sure, in generating my quads that all 4 corners lie on a plane. What does opengl do if you give it a quad not all on one plane? I mean it must divide if into 2 tris but which way? Has anyone ipmplemented a terrain engine like this, and what have you done and why? Also, I''m trying to make the landscape engine into a class.. do you guys think this is feasable? Thanks

one bit I''m pretty certain about in all that is that if you send OGL a Quad which isnt all one plane then it tends not to draw the quad.
tbh your better off spliting it up into tris as sending large amounts of tris down the pipeline will be faster than a large amount of quads, in this situation at least.

Non coplanar quads difficult to deal with for calculations. Just use triangles, its easier to deal with because they are always coplanar. Besides, your quad will get broken into triangles to be rendered anyways.