The Triangulate modifier converts all faces in a mesh (quads and n-gons) to triangular faces. It fulfills the exact same function as the Triangulate tool in Edit Mode.
- Quad Method
Split the quads in nice triangles, slower method.
Split the quads on their 1st and 3rd vertices.
- Fixed Alternate
Split the quads on their 2nd and 4th vertices.
- Shortest Diagonal
Split the quads along their shortest diagonal.
- Longest Diagonal
Split the quads along their longest diagonal. This is the preferred mode for cloth simulations.
- N-gon Method
Arrange the new triangles nicely, slower method.
Splits n-gons using an ear-clipping algorithm (the same method of tessellation used for viewport display).
- Minimum Vertices
Minimum number of vertices a face must have to be triangulated. For example, setting this value to 5, will prevent triangulation of Quads and only triangulate N-gons.
- Keep Normals
When using custom normals, try to preserve the same shading as before triangulation.