Quads vs. Triangles

Created Aug 4, 2026 · Updated Aug 5, 2026

Four of the eight formats always triangulate on export, no matter how the created topology is actually shaped: glTF, GLB, STL and 3MF. glTF 2.0, STL and 3MF simply have no quad primitive to write one into.

The other four — OBJ, PLY, FBX and Collada (DAE) — preserve quads natively: a genuine quad is written as a real 4-index face, and only a face that's internally a degenerate quad (a true triangle stored in quad-padded form) collapses back down to three indices.

The same quad-heavy created topology exported to OBJ, keeping real 4-index quad faces, versus exported to glTF, with every quad split into two triangles — The same topology exported with quads intact (OBJ) versus triangulated (glTF).

Exporting Rigged glTF always triangulates too, for the same reason — glTF is the only format that path can ever write — splitting each quad along whichever diagonal the created topology itself already chose, rather than an arbitrary one.