Topology mirror does not work #28543

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ronan ducluzeau · 2011-09-07T14:57:54+02:00

ronan ducluzeau commented

2011-09-07 14:57:54 +02:00

%%%ubuntu 11.04 64 bits rev 40010

Problem was reported on french forum blenderclan by a member trying to do a CG Cookie's tutorial.
http://blenderclan.tuxfamily.org/html/modules/newbb/viewtopic.php?topic_id=32087

I searched about the status of this feature. But I did not find nothing except this thread on BlenderArtists where nobody seems to have this feature working.
http://blenderartists.org/forum/showthread.php?194567-Topology-mirror-in-2.5-How-to-use

I tried this feature in Bmesh.
It is not perfect but it works.

In the attached .blend move selected vertex, the opposite should move as it is when .blend is open in a Bmesh build.
%%%

%%%ubuntu 11.04 64 bits rev 40010 Problem was reported on french forum blenderclan by a member trying to do a CG Cookie's tutorial. http://blenderclan.tuxfamily.org/html/modules/newbb/viewtopic.php?topic_id=32087 I searched about the status of this feature. But I did not find nothing except this thread on BlenderArtists where nobody seems to have this feature working. http://blenderartists.org/forum/showthread.php?194567-Topology-mirror-in-2.5-How-to-use I tried this feature in Bmesh. It is not perfect but it works. In the attached .blend move selected vertex, the opposite should move as it is when .blend is open in a Bmesh build. %%%

ronan ducluzeau commented

2011-09-07 14:57:54 +02:00

Changed status to: 'Open'

Sergey Sharybin commented

2011-09-07 15:04:51 +02:00

%%%As tooltip for topology mirror option says, it's supposed to work for cases mesh has got matching unique topology on both sides. It's more a TODO item than bug, closing.%%%

ronan ducluzeau commented

2011-09-07 19:57:10 +02:00

%%%If it is a todo, for after next release, it should be hidden in the UI.%%%

ronan ducluzeau commented

2011-09-07 19:59:37 +02:00

%%%When it is enabled, it make X-mirror inactive.%%%

Sergey Sharybin commented

2011-09-07 20:10:28 +02:00

%%%It's not a TODO in terms it's work-in-progress or unfinished tool, it's just tool with some restrictions on usage. It fails for simple cases like your file but it works fine for Big Buck Bunny and Sintel models (which are symmetrical and unique topology).%%%

ronan ducluzeau commented

2011-09-08 10:26:46 +02:00

%%%OK, it works with Big Buck Bunny but it does not with a simple subdivided cube.
So, I had to smooth the cube. delete on side, add a miror modifier, extrude faces to have to more that one arm and apply mirror modifier to get it working.

Sorry but my subdivided cube correspond to tooltip. It is a symmetrical and unique topology.
How can the user have an idea of restrictions on usage ?
What is the required level of complexity ?
Does it only work for model which have ears, arms and legs or does it work if I model a snake ?
Is there a minimal number of faces ?
Do you ignore these restrictions, too ?

Is it possible to grey out this option until conditions are good to use it ?

%%%

%%%OK, it works with Big Buck Bunny but it does not with a simple subdivided cube. So, I had to smooth the cube. delete on side, add a miror modifier, extrude faces to have to more that one arm and apply mirror modifier to get it working. Sorry but my subdivided cube correspond to tooltip. It is a symmetrical and unique topology. How can the user have an idea of restrictions on usage ? What is the required level of complexity ? Does it only work for model which have ears, arms and legs or does it work if I model a snake ? Is there a minimal number of faces ? Do you ignore these restrictions, too ? Is it possible to grey out this option until conditions are good to use it ? %%%

Campbell Barton commented

2011-09-15 08:12:42 +02:00

%%%This is not a TODO, it works as intended.

Topo mirror allows an asymmetrical character to be weight painted with mirror enabled, X-Mirror cant do this.

Topo mirror works in some cases but not all. for subdivided cubes it fails but for real projects with character models it often works quite well, whereas - for very very simple cases there is not enough unique topology to calculate a mirror.

Just as X mirror assumes exact X-Axis flipping and is otherwise not useful, Topo mirror assumes a continuous surface with unique-enough topology as to be able to calculate the mirror.

closing this report.
%%%

%%%This is not a TODO, it works as intended. Topo mirror allows an asymmetrical character to be weight painted with mirror enabled, X-Mirror cant do this. Topo mirror works in some cases but not all. for subdivided cubes it fails but for real projects with character models it often works quite well, whereas - for very very simple cases there is not enough unique topology to calculate a mirror. Just as X mirror assumes exact X-Axis flipping and is otherwise not useful, Topo mirror assumes a continuous surface with unique-enough topology as to be able to calculate the mirror. closing this report. %%%

Campbell Barton commented

2011-09-15 08:12:42 +02:00

Changed status from 'Open' to: 'Archived'

Campbell Barton closed this issue

2011-09-15 08:12:42 +02:00

ronan ducluzeau commented

2011-09-15 10:56:21 +02:00

%%%But what means "enough topology".
This is the reason of my questions.

I posted link to blenderartists to show that nobody understand the tooltip.
For the users, it is equal to : "Sometimes, it works. Sometimes it doesn't."

I add a X_topology_example.blend which is not a subvdivided cube.

It demonstrates that this feature can be working on some parts of the mesh and not on the others.
It can also works perfectly with few faces.
%%%

%%%But what means "enough topology". This is the reason of my questions. I posted link to blenderartists to show that nobody understand the tooltip. For the users, it is equal to : "Sometimes, it works. Sometimes it doesn't." I add a X_topology_example.blend which is not a subvdivided cube. It demonstrates that this feature can be working on some parts of the mesh and not on the others. It can also works perfectly with few faces. %%%

Vyacheslav Kobozev commented

2020-04-08 23:09:32 +02:00

Added subscriber: @Vyach

Vyacheslav Kobozev commented

2020-04-08 23:09:32 +02:00

@ideasman42 But why it shouldnt work with subdivided cube? What the problem with its topology? Why the part of character`s mesh can not be simple?
Is there a way to put vertices on the left and on the right part in the symmetrical list, so they will act like topology mirrored despite any deformations?

I mean situations like this. It is obvious what verteces moved.

Also, usually user work with mirror modifier before to make mesh geometry assymetric. So it can be used to set topology order for vertices.
Can it work with homeomorphism?
May be later, when blendshapes and keymeshes will implemented?

@ideasman42 But why it shouldn`t work with subdivided cube? What the problem with it`s topology? Why the part of character`s mesh can not be simple? Is there a way to put vertices on the left and on the right part in the symmetrical list, so they will act like topology mirrored despite any deformations? I mean situations like this. It is obvious what verteces moved. ![34300805.jpg](https://archive.blender.org/developer/F8457774/34300805.jpg) Also, usually user work with mirror modifier before to make mesh geometry assymetric. So it can be used to set topology order for vertices. Can it work with homeomorphism? May be later, when blendshapes and keymeshes will implemented?

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Topology mirror does not work #28543