Procedurally generated flat shaded mesh

I'm creating a mesh procedurally, but for the sake of generating time I just simply used shared vertices, and now the whole mesh is smooth. Can I achieve flat shading without giving each triangle it's own vertices (I wouldn't mind a solution with a shader too). Thanks in advance, gorbit99

 

The model importer (this has little to do with your use-case, but bear with me) has a setting for Normals in which you can choose "Calculate" and then set a maximum angle at which to smooth vertices. From what I understand, this is actually accomplished by generating additional vertices (if they didn't exist already and you need them) or combining vertices (if they did exist and you don't need them) for all of the triangles in the model. If you import a box model with 8 verts, it'll look smoothed, but if you set the importer to Calculate the normals and then set the max angle to 0, it'll actually have 24 verts when used in Unity. The Unity cube primitive also has 24 verts.

It may be possible to have a shader that makes the model appear flat, but it's important to know that "flat" is actually expressly defined as "having separate vertices per triangle", so going out of your way to avoid that scenario seems a little masochistic, lol.

 

Does giving the mesh separate triangles really mess up generation time that much?

The flat or smooth appearance is more to do with the normals then the underlying mesh topography. How are you setting the normals?

 

Well, if you create objects at a large scale, then it will slow it down, but I can live with that I guess

I'm not calculating them, I just call Mesh#RecalculateNormals()

 

From my understanding, it only has to do with normals if those extra vertices are actually there, otherwise the "1 normal per point" limitation doesn't really give you much choice in the matter. Could be wrong of course though, this isn't exactly an area I'm super-familiar with.

 

You could go with UVs and a normal map. But this seems more complex then simply using the right number of vertices.

Don't guess, profile.

How often are you generating this mesh that adding a few more Vector3 gives you a slowdown problem?

 

It's a terrain, so it generates once, but then almost never changes (or even if it is changing, only a small fraction of the whole terrain)