Mirror+Bevel modifiers produce incorrect result. #37916

New Issue

Greg Zaal · 2013-12-22T14:28:17+01:00

Greg Zaal commented

2013-12-22 14:28:17 +01:00

System Information
Windows 7 64 bit, 2x gtx 570

Blender Version
Broken: Blender 2.69, built 2013-12-18 18:35, hash 4b206af
Worked: Blender 2.69 r61228

Short description of error
When using a mirror modifer above a bevel modifier, the bevels on the mirrored side of the mesh are incorrect: http://i.imgur.com/lUdZMfj.jpg
When viewing vertex normals, you can see the mirrored verts have strange normals which is probably the cause of it: http:*i.imgur.com/3RGGzIx.png (though in older builds that work, the vert normals show strangely as well but the bevel works fine: http:*i.imgur.com/zCiwvXd.png)

Exact steps for others to reproduce the error

Add an edge loop vertically on the default cube
Delete the four verts on one side
Add a mirror modifier and set the axis appropriately
Add a bevel modifier.

This is probably due to recent changes to the bevel modifier ([rev1 ]], http:*developer.blender.org/rB1158c1f7c0ec3f5d31989cb85207a08888d2c0d3 , http:*developer.blender.org/rB7a899ce9fc7fbcea219c12afe49c08114505b3aa , http:*developer.blender.org/rB9a78cda32111be9e1c9e2b9c158b27334d3c8804 , http:*developer.blender.org/rB39673718864f018307e49fac62696341b3230628 , http:*developer.blender.org/rBbfb9cefccbf8ff9733e9739e9c4dbc93a762bebe ), but could also be because of changes to the mirror modifier ([ http://developer.blender.org/rB7214001cdb142cb2556135b1f6e35290c62b9a69 | rev ). Or both.

**System Information** Windows 7 64 bit, 2x gtx 570 **Blender Version** Broken: Blender 2.69, built 2013-12-18 18:35, hash 4b206af Worked: Blender 2.69 r61228 **Short description of error** When using a mirror modifer above a bevel modifier, the bevels on the mirrored side of the mesh are incorrect: http://i.imgur.com/lUdZMfj.jpg When viewing vertex normals, you can see the mirrored verts have strange normals which is probably the cause of it: http:*i.imgur.com/3RGGzIx.png (though in older builds that work, the vert normals show strangely as well but the bevel works fine: http:*i.imgur.com/zCiwvXd.png) **Exact steps for others to reproduce the error** 1. Add an edge loop vertically on the default cube 2. Delete the four verts on one side 3. Add a mirror modifier and set the axis appropriately 4. Add a bevel modifier. This is probably due to recent changes to the bevel modifier ([rev1 ]], [[ http:*developer.blender.org/rB1158c1f7c0ec3f5d31989cb85207a08888d2c0d3 | rev2 ]], [[ http:*developer.blender.org/rB7a899ce9fc7fbcea219c12afe49c08114505b3aa | rev3 ]], [[ http:*developer.blender.org/rB9a78cda32111be9e1c9e2b9c158b27334d3c8804 | rev4 ]], [[ http:*developer.blender.org/rB39673718864f018307e49fac62696341b3230628 | rev5 ]], [[ http:*developer.blender.org/rBbfb9cefccbf8ff9733e9739e9c4dbc93a762bebe | rev6 ]]), but could also be because of changes to the mirror modifier ([[ http://developer.blender.org/rB7214001cdb142cb2556135b1f6e35290c62b9a69 | rev ](http:*developer.blender.org/rBda91575206cda63966fbd526378de98a866e8e5c)). Or both.

Greg Zaal commented

2013-12-22 14:28:17 +01:00

Changed status to: 'Open'

Greg Zaal commented

2013-12-22 14:28:17 +01:00

Added subscriber: @GregZaal

blender-admin commented

2013-12-22 14:28:17 +01:00

#38508 was marked as duplicate of this issue

blender-admin commented

2013-12-22 14:28:17 +01:00

#38534 was marked as duplicate of this issue

Campbell Barton self-assigned this 2013-12-28 14:13:16 +01:00

David M commented

2014-01-23 11:15:08 +01:00

Added subscriber: @erwin94

David M commented

2014-01-23 11:15:08 +01:00

This is reproducible with a couple of constructive modifiers, it seems like a bevel problem.
(Note that the problem disappears in all cases if the first modifier is applied)

This is reproducible with a couple of constructive modifiers, it seems like a bevel problem. (Note that the problem disappears in all cases if the first modifier is applied)

Brecht Van Lommel commented

2014-02-05 21:50:02 +01:00

Added subscribers: @b_d, @ideasman42

Brecht Van Lommel commented

2014-02-05 21:50:02 +01:00

◀ Merged tasks: #38508.

Brecht Van Lommel commented

2014-02-07 13:08:57 +01:00

Added subscribers: @KenanBolukbasi, @howardt

Brecht Van Lommel commented

2014-02-07 13:08:57 +01:00

◀ Merged tasks: #38534.

Howard Trickey commented

2014-02-07 15:15:41 +01:00

The problem is that bevel depends on both vertex and face normals, and the BMesh obtained from the DerivedMesh does not get mirrored vertex normals for mirrored vertices.
I'll have a look to see if I can figure out where that could/should be fixed.

The problem is that bevel depends on both vertex and face normals, and the BMesh obtained from the DerivedMesh does not get mirrored vertex normals for mirrored vertices. I'll have a look to see if I can figure out where that could/should be fixed.

Brecht Van Lommel commented

2014-02-07 15:19:16 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2014-02-07 15:19:16 +01:00

Perhaps it's just a matter of setting dependsOnNormals in the ModifierTypeInfo like e.g. the solidify modifier does.

Howard Trickey commented

2014-02-07 16:40:49 +01:00

Thanks brecht, I wasn't aware of that modifier property. That works, and I will commit a change to fix this in a moment.

I'm a little unclear why the mechanism for asking for vertex normals to be recalculated appears to be different from the mechanism to get face normals recalculated (the latter can be gotten by passing 'true' as the second argument to DM_to_bmesh. I was toying with adding a third argument to DM_to_bmesh to ask for vertex recalculation, but since the changing the modifier info works, I will use that route.

Thanks brecht, I wasn't aware of that modifier property. That works, and I will commit a change to fix this in a moment. I'm a little unclear why the mechanism for asking for vertex normals to be recalculated appears to be different from the mechanism to get face normals recalculated (the latter can be gotten by passing 'true' as the second argument to DM_to_bmesh. I was toying with adding a third argument to DM_to_bmesh to ask for vertex recalculation, but since the changing the modifier info works, I will use that route.

Howard Trickey commented

2014-02-07 16:52:45 +01:00

Fixed with commit b4fb1e6d9f

Fixed with commit b4fb1e6d9f

Howard Trickey commented

2014-02-07 16:52:56 +01:00

Changed status from 'Open' to: 'Resolved'

Howard Trickey closed this issue

2014-02-07 16:52:56 +01:00

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Mirror+Bevel modifiers produce incorrect result. #37916