How do you un-triangulate a mesh?

Question

I know that you can triangulate a selected portion of a mesh in Edit Mode by hitting CtrlT. This converts all quads and n-gons into tris. How how can this be reversed, combining coplanar triangles into quads and n-gons?

Keavon · Accepted Answer · 2014-07-03T11:50:19.383

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You can untriangulate the selected portion of a mesh by hitting AltJ. This will only create quads so some manual cleanup may be necessary if you need n-gons. You can do this by selecting the leftover edges and hitting X and clicking Dissolve Edges.

edited Jul 03 '14 at 11:50

answered Jul 03 '14 at 09:54

Keavon

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This command is also available from the 3D view menus: Mesh > Faces > Tris to Quads – smashuu Jul 21 '17 at 21:17

score 9 · Answer 2 · answered Jul 03 '14 at 13:10

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You can use the decimate modifier using the planar option and apply it.

answered Jul 03 '14 at 13:10

pink vertex

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This also turns them to n-gons while Alt J does not. Note that it likely won't work to set the Angle Limit to 0. – Keavon Jul 03 '14 at 14:44
Note that this is the same as Limited dissolve in edit mode. – gandalf3 Jul 03 '14 at 19:49
Note: this will most likely screw up your UV map. – Keavon Sep 15 '14 at 03:56

score 2 · Answer 3 · answered May 27 '20 at 11:32

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import bpy
bpy.ops.object.editmode_toggle()
bpy.ops.mesh.select_all(action='SELECT')
bpy.ops.mesh.tris_convert_to_quads()

answered May 27 '20 at 11:32

matt henderson

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One liners and code without context rarely make a good answer. Could you expand on how this helps and why? – Duarte Farrajota Ramos May 27 '20 at 15:18
yeah, right good feedback – matt henderson Jun 25 '20 at 00:30
Still works in 2022 on Blender 2.3.2 thanks! – myselfhimself Oct 28 '22 at 12:11
This piece of code fits well if you do not want to use a modifier – myselfhimself Oct 28 '22 at 12:12

score 1 · Answer 4 · answered Feb 22 '18 at 06:15

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You can also do it through Blender's Python API if you want to get quads:

bpy.ops.mesh.tris_convert_to_quads()

answered Feb 22 '18 at 06:15

Amir

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How do you un-triangulate a mesh?

4 Answers4