Ply format triangulation #62478

New Issue

Mikhail Gavrilec · 2019-03-12T06:20:27+01:00

Mikhail Gavrilec commented

2019-03-12 06:20:27 +01:00

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.

**System Information** Operating system: Ubuntu 18.04.2 Graphics card: GT 1030 **Blender Version** Broken: Blender 2.8 ![image.png](https://archive.blender.org/developer/F6808229/image.png) 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.

Mikhail Gavrilec commented

2019-03-12 06:20:27 +01:00

Added subscriber: @MikhailGavrilec

Bastien Montagne commented

2019-03-12 11:07:22 +01:00

Added subscribers: @ideasman42, @mont29

Campbell Barton was assigned by Bastien Montagne

2019-03-12 11:07:22 +01:00

Bastien Montagne commented

2019-03-12 11:07:22 +01:00

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 @ideasman42 decide here.

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 @ideasman42 decide here.

name commented

2019-09-17 00:44:47 +02:00

Added subscriber: @name

name commented

2019-09-17 00:48:53 +02:00

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.

Bastien Montagne commented

2019-09-17 08:49:13 +02:00

@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.

Mikhail Gavrilec commented

2019-09-17 08:55:51 +02:00

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.