really appreciate your help.
but hereâ€™s the differenceďĽŚI created the geometry with BufferGeometry,so thereâ€™s no way to get geometry.parameters and segments.my points is arranged regularly, but there is no triangular face index.

In my addon, I have provided the option of splitting rectangles into four triangles using a central point. There is one variant each for indexed and non-indexed BufferGeometry.