Convert to curve poor result #60859

New Issue

stephen leger · 2019-01-25T13:23:57+01:00

stephen leger commented

2019-01-25 13:23:57 +01:00

System Information
Operating system: Linux Mint 19
Graphics card: Nvidia 1070

Blender Version
Broken: 2.8
Worked: 2.79

Short description of error
Convert to curve fails.

Exact steps for others to reproduce the error
Load the file, use object -> convert to curve, only half of object succeed.
bug_to_curve.blend

**System Information** Operating system: Linux Mint 19 Graphics card: Nvidia 1070 **Blender Version** Broken: 2.8 Worked: 2.79 **Short description of error** Convert to curve fails. **Exact steps for others to reproduce the error** Load the file, use object -> convert to curve, only half of object succeed. [bug_to_curve.blend](https://archive.blender.org/developer/F6399630/bug_to_curve.blend)

stephen leger commented

2019-01-25 13:23:57 +01:00

Added subscriber: @StephenLeger

Jacques Lucke commented

2019-01-25 13:29:53 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2019-01-25 13:29:54 +01:00

Can you try to create a simpler example that works in 2.79 but not in 2.8?
I noticed that converting Suzanne to seems to have a similar problem, but it works the same in both versions of Blender.

Can you try to create a simpler example that works in 2.79 but not in 2.8? I noticed that converting Suzanne to seems to have a similar problem, but it works the same in both versions of Blender.

stephen leger commented

2019-01-25 16:00:29 +01:00

Both samples does work in 2.79 but not in 2.8
Basically i do slice geometry using

bpy.ops.mesh.bisect(
                        'INVOKE_DEFAULT',
                        plane_co=plane_co,
                        plane_no=plane_no,
                        use_fill=True,
                        clear_inner=True,
                        clear_outer=True)

and then convert result to curve.
Doing so never was a problem in 2.79, even on complex meshes as shown in file 1.

bug_to_curve.blend

Both samples does work in 2.79 but not in 2.8 Basically i do slice geometry using ``` bpy.ops.mesh.bisect( 'INVOKE_DEFAULT', plane_co=plane_co, plane_no=plane_no, use_fill=True, clear_inner=True, clear_outer=True) ``` and then convert result to curve. Doing so never was a problem in 2.79, even on complex meshes as shown in file 1. [bug_to_curve.blend](https://archive.blender.org/developer/F6400733/bug_to_curve.blend)

Jacques Lucke commented

2019-01-25 16:42:42 +01:00

Maybe it helps when you don't use the use_fill option so that you don't have any faces left?

Maybe it helps when you don't use the `use_fill` option so that you don't have any faces left?

stephen leger commented

2019-01-25 17:12:04 +01:00

Ok,
removing faces does fix the issue, but it's a regression from 2.79

Ok, removing faces does fix the issue, but it's a regression from 2.79

Sebastian Parborg commented

2019-01-28 16:22:18 +01:00

Added subscriber: @ZedDB

Sebastian Parborg commented

2019-01-28 16:22:18 +01:00

Do you get the same problem with the 2.79 build from here? https://builder.blender.org/download/

I get the exact same result on both the latest 2.79 build and 2.8. So I'm guessing this it is not really 2.8 related. (So it's a regression for both)

Do you get the same problem with the 2.79 build from here? https://builder.blender.org/download/ I get the exact same result on both the latest 2.79 build and 2.8. So I'm guessing this it is not really 2.8 related. (So it's a regression for both)

stephen leger commented

2019-01-28 17:15:21 +01:00

Same geometry is failing on both 2.79c and 2.8 (using crtl+c and paste to move between apps)

However building geometry using bpy.ops.bisect() and then convert does succeed in both
2.79c and 2.79 d377cd5db1
but fails in 2.8 690478027b (i've to remove faces to make it work as in 2.79)

So looks like bisect output is not consistent across blender's versions.

Same geometry is failing on both 2.79c and 2.8 (using crtl+c and paste to move between apps) However building geometry using bpy.ops.bisect() and then convert does succeed in both 2.79c and 2.79 d377cd5db19a but fails in 2.8 690478027bd7 (i've to remove faces to make it work as in 2.79) So looks like bisect output is not consistent across blender's versions.

Sebastian Parborg commented

2019-01-28 18:01:47 +01:00

How do i bisect the mesh in 2.79 to make it work?

stephen leger commented

2019-01-28 18:04:58 +01:00

In edit mode if i recall correctly

- plane co: coord of one point in bisect plane
- plane no: vector of bisect plane normal
bpy.ops.mesh.bisect(
                        'INVOKE_DEFAULT',
                        plane_co=plane_co,
                        plane_no=plane_no,
                        use_fill=True,
                        clear_inner=True,
                        clear_outer=True)

see in action:
https://youtu.be/AmPDyhwBA8w?t=31

In edit mode if i recall correctly ``` - plane co: coord of one point in bisect plane - plane no: vector of bisect plane normal bpy.ops.mesh.bisect( 'INVOKE_DEFAULT', plane_co=plane_co, plane_no=plane_no, use_fill=True, clear_inner=True, clear_outer=True) ``` see in action: https://youtu.be/AmPDyhwBA8w?t=31

Sebastian Parborg commented

2019-01-28 18:35:35 +01:00

Yes, but in the example files you have to slice it somewhere.

Or are you not bisecting the mesh in bug_to_curve.blend ?

Yes, but in the example files you have to slice it somewhere. Or are you not bisecting the mesh in `bug_to_curve.blend` ?

stephen leger commented

2019-01-28 22:08:13 +01:00

The bug_to_curve.blend file is a result of bisect done through same code as seen in video, but under 2.8

Sebastian Parborg commented

2019-01-28 22:34:26 +01:00

Added subscriber: @ideasman42

Sebastian Parborg commented

2019-01-28 22:34:26 +01:00

@ideasman42 any ideas?

Campbell Barton commented

2019-01-28 23:06:01 +01:00

There are many duplicate faces in this mesh causing curve conversion to fail in those cases.

Blender should never create duplicate faces, so the issue is likely a spesific tool or script.

While removing double faces on entering edit-mode is possible, it's going to slow things down so I'd rather first find out how the mesh was created.

There are many duplicate faces in this mesh causing curve conversion to fail in those cases. Blender should never create duplicate faces, so the issue is likely a spesific tool or script. While removing double faces on entering edit-mode is possible, it's going to slow things down so I'd rather first find out how the mesh was created.

stephen leger commented

2019-01-28 23:15:59 +01:00

Will check twice the mesh generation code - to ensure there is no dups as i do join() meshes together before bisect().
But as far as i can tell, exact same code was (is) working without any trouble under 2.79c and 2.79 lastest buildbot

The workaround for this issue in code is to remove all faces.

Will check twice the mesh generation code - to ensure there is no dups as i do join() meshes together before bisect(). But as far as i can tell, exact same code was (is) working without any trouble under 2.79c and 2.79 lastest buildbot The workaround for this issue in code is to remove all faces.

Jacques Lucke commented

2019-03-07 15:11:27 +01:00

Is this still an issue?