Mirrored linked objects flip in Edit mode vs Object mode #68097

New Issue

Jeremy Gallagher · 2019-08-02T02:56:08+02:00

Jeremy Gallagher commented

2019-08-02 02:56:08 +02:00

System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.60

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f5449
Worked: (optional)

Short description of error
When I Link Object data for multiple objects and apply a mirror modifier and link that modifier, while in object mode the model looks exactly how I'd like. However, when I rotate one of the linked & mirrored objects and go into edit mode, the objects flip sides and appear to be out of place.

Exact steps for others to reproduce the error
I follow these steps in Object mode:

I remove the backside planks
select all 4 of the front planks
ctrl+l and link object data.
I then select the top plank, and add a mirror modifier on the Y axis and it properly mirrors to the back side of the chest after I use the 'dropper' to choose the rim.
I then hit ctrl+l to link the modifiers, and all planks appear on the backside (screenshot 1)
I select the bottom plank (screenshot 2)

I hit tab to enter Edit mode

Before:

After rotating a plank and then switching into Edit mode:

As you can see, for some reason while in Edit mode, the other 3 mirrored planks appear on the wrong side of the chest, but they appear in the correct place while in object mode. I reached out to the CG Cookie community to see if anyone else has experienced this, and they are able to recreate the issue in Blender 2.80 but cannot reproduce in Blender 2.79 which leads me to believe it's a 2.80 issue.

tresurechest.blend

**System Information** Operating system: Windows-10-10.0.18362 64 Bits Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.60 **Blender Version** Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: `f6cb5f5449` Worked: (optional) **Short description of error** When I Link Object data for multiple objects and apply a mirror modifier and link that modifier, while in object mode the model looks exactly how I'd like. However, when I rotate one of the linked & mirrored objects and go into edit mode, the objects flip sides and appear to be out of place. **Exact steps for others to reproduce the error** I follow these steps in Object mode: - I remove the backside planks - select all 4 of the front planks - ctrl+l and link object data. - I then select the top plank, and add a mirror modifier on the Y axis and it properly mirrors to the back side of the chest after I use the 'dropper' to choose the rim. - I then hit ctrl+l to link the modifiers, and all planks appear on the backside (screenshot 1) - I select the bottom plank (screenshot 2) # I hit tab to enter Edit mode Before: ![image.png](https://archive.blender.org/developer/F7642922/image.png) After rotating a plank and then switching into Edit mode: ![image.png](https://archive.blender.org/developer/F7642924/image.png) As you can see, for some reason while in Edit mode, the other 3 mirrored planks appear on the wrong side of the chest, but they appear in the correct place while in object mode. I reached out to the CG Cookie community to see if anyone else has experienced this, and they are able to recreate the issue in Blender 2.80 but cannot reproduce in Blender 2.79 which leads me to believe it's a 2.80 issue. [tresurechest.blend](https://archive.blender.org/developer/F7642919/tresurechest.blend)

Jeremy Gallagher commented

2019-08-02 02:56:08 +02:00

Added subscriber: @jeremyhgs

Bastien Montagne commented

2019-08-02 10:56:37 +02:00

Added subscriber: @mont29

Bastien Montagne self-assigned this 2019-08-02 10:56:37 +02:00

Bastien Montagne commented

2019-08-02 10:56:37 +02:00

Confirmed, not sure what's happenning here, looks like in Edit mode the active object's transform is used for all modifiers evaluations...

Bastien Montagne removed their assignment 2019-08-02 11:27:07 +02:00

Clément Foucault was assigned by Bastien Montagne

2019-08-02 11:27:07 +02:00

Bastien Montagne commented

2019-08-02 11:27:07 +02:00

Added subscribers: @fclem, @Jeroen-Bakker

Bastien Montagne commented

2019-08-02 11:27:07 +02:00

Not sure what's happening here, generated coordinates from the modifier itself are 100% valid and identical in both Object and Edit mode.

@fclem, @Jeroen-Bakker could it be some kind of optimization in Edit mode draw code, that would e.g. assume that when two objects share the same mesh, then they also share the same evaluated geometry?

Not sure what's happening here, generated coordinates from the modifier itself are 100% valid and identical in both Object and Edit mode. @fclem, @Jeroen-Bakker could it be some kind of optimization in Edit mode draw code, that would e.g. assume that when two objects share the same mesh, then they also share the same evaluated geometry?

Clément Foucault was unassigned by Dalai Felinto

2019-12-23 16:33:26 +01:00

Clément Foucault commented

2020-01-27 18:35:18 +01:00

In edit mode, the edit mesh is used to extract the data used for GPU rendering, and in this particular situation the me->edit_mesh is shared. I don't know how to proceed as every objects that use the same mesh data are tagged as in edit mode and will use the same edit mesh.

This does fix the issue but then the edits are not visible on instances untill you go out of edit mode.

@@ -1069,17 +1070,13 @@ void DRW_mesh_batch_cache_create_requested(
   /* Sanity check. */
   if ((me->edit_mesh != NULL) && (ob->mode & OB_MODE_EDIT)) {
     BLI_assert(me->edit_mesh->mesh_eval_final != NULL);
   }
 
-  const bool is_editmode =
-      (me->edit_mesh != NULL) &&
-      (/* Simple case, the object is in edit-mode with an edit-mesh. */
-       (ob->mode & OB_MODE_EDIT) ||
-       /* This is needed so linked duplicates show updates while the user edits the mesh.
-        * While this is not essential, it's useful to see the edit-mode changes everywhere. */
-       (me->edit_mesh->mesh_eval_final != NULL));
+  const bool is_editmode = (me->edit_mesh != NULL) &&
+                           (/* Simple case, the object is in edit-mode with an edit-mesh. */
+                            (ob->mode & OB_MODE_EDIT));
 
   DRWBatchFlag batch_requested = cache->batch_requested;
   cache->batch_requested = 0;
 
   if (batch_requested & MBC_SURFACE_WEIGHTS) {

In edit mode, the edit mesh is used to extract the data used for GPU rendering, and in this particular situation the `me->edit_mesh` is shared. I don't know how to proceed as every objects that use the same mesh data are tagged as in edit mode and will use the same edit mesh. This does fix the issue but then the edits are not visible on instances untill you go out of edit mode. ``` @@ -1069,17 +1070,13 @@ void DRW_mesh_batch_cache_create_requested( /* Sanity check. */ if ((me->edit_mesh != NULL) && (ob->mode & OB_MODE_EDIT)) { BLI_assert(me->edit_mesh->mesh_eval_final != NULL); } - const bool is_editmode = - (me->edit_mesh != NULL) && - (/* Simple case, the object is in edit-mode with an edit-mesh. */ - (ob->mode & OB_MODE_EDIT) || - /* This is needed so linked duplicates show updates while the user edits the mesh. - * While this is not essential, it's useful to see the edit-mode changes everywhere. */ - (me->edit_mesh->mesh_eval_final != NULL)); + const bool is_editmode = (me->edit_mesh != NULL) && + (/* Simple case, the object is in edit-mode with an edit-mesh. */ + (ob->mode & OB_MODE_EDIT)); DRWBatchFlag batch_requested = cache->batch_requested; cache->batch_requested = 0; if (batch_requested & MBC_SURFACE_WEIGHTS) { ```

Jeroen Bakker commented

2020-05-18 11:31:03 +02:00

Closed as duplicate of #72733

Jeroen Bakker closed this issue

2020-05-18 11:31:03 +02:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Mirrored linked objects flip in Edit mode vs Object mode #68097

I hit tab to enter Edit mode