Page MenuHome

Ply format triangulation
Closed, ResolvedPublic

Description

System Information
Operating system: Ubuntu 18.04.2
Graphics card: GT 1030

Blender Version
Broken: Blender 2.8


Worked: I didn't have that problem in 2.79

Short description of error
When you export ply format from Blender it exports with triangulation. I didn't have that problem in 2.79.
Exact steps for others to reproduce the error
Create Suzane in blender and export it as ply with everything unchecked in export panel. And after that import again in ply format.

Event Timeline

Bastien Montagne (mont29) triaged this task as Confirmed, Medium priority.

2.8 add-on code uses looptris, which only generates triangles, while in 2.7 it was using tessellated data, which could also generate quads.

Don’t think that this is a bug, more like some design decision, but will let @Campbell Barton (campbellbarton) decide here.

Campbell Barton (campbellbarton) lowered the priority of this task from Confirmed, Medium to Confirmed, Low.Mar 21 2019, 2:34 PM

Since exporting as OBJ correctly keeps quads, and the PLY format supports quads as well, I feel that Blender should keep quads when exporting to PLY (same behavior as 2.79). I was very surprised to see that my mesh had been triangulated.

@__name__ obj exports polygons (hence also quads) by default, if you turn on the triangulation option it will also only export triangles now. PLY does not support polygons.

I used ply exporter to export hexahedral meshes for a program that converts ply files to vtk files (ply file has to contain only quads for this). Now I can use only 2.79 for this.