Child bone frozen when both Auto IK and X-Axis mirror are used #75810

New Issue

marc · 2020-04-17T04:59:11+02:00

marc commented

2020-04-17 04:59:11 +02:00

System Information
Operating system: Windows-10-10.0.17763-SP0 64 Bits
Graphics card: AMD Radeon HD 8370D ATI Technologies Inc. 4.5.13399 Core Profile Context 15.200.1062.1004

Blender Version
Broken: version: 2.83 (sub 13), branch: master, commit date: 2020-04-08 21:23, hash: 1239cab11f
(Broken in both version 2.83 alpha and 2.83 beta)

Worked: 2.82

Short description of error

When both X-axis mirror and Auto ik are activated in Pose mode, grabbing or rotating a bone with a mirror opposite bone (armL and armR for example) then Disabling X-Axis Mirror causes the child of the opposite bone to no longer move when using the grab tool (G).
After that the only way to get Auto IK to behave properly on the frozen bone is to re-enable X-Axis mirror then grab any bone that has no child on opposite side.

Exact steps for others to reproduce the error

From default startup:
1 - Create armature with a bone that has both: a child bone and a mirrored bone. For example, a spine with two arms (the parents) with forearms (the childs).
2 - Enable both 'X-Axis Mirror' and 'Auto IK'.
3 - Select a parent mirrored bone, the upper arm in this case, grab it, then move it somewhere or release it, doesn't matter.
4 - Disable X-Axis Mirror, keep Auto IK activated.
4 - The child bone of the mirrored bone, the forearm in this case, is now "frozen". Grabbing it with Auto IK enabled changes it's transform location property values but the bone does not move. It can still be rotated. Disabling Auto IK allows it to be moved again until Auto IK is re-enabled.

The only way to unfreeze that bone is to enable both Auto IK and X-Axis Mirror yet again then select a bone that has no child (otherwise you'll freeze another bone), grab it, release it, the disable X-Axis Mirror. The bone can now be grabbed and moved with Auto IK enabled as expected.

From .blend file:
1 - Grab either forearm.L or hand.L and move it. (Already in Pose mode and Auto IK is enabled)
2 - In 2.83 alpha and beta It/they won't move. They can be moved in 2.82.

( The file includes a rigify rig but the bug has nothing to do with rigify, i've tested with a stock armature )

blenbug3.blend

**System Information** Operating system: Windows-10-10.0.17763-SP0 64 Bits Graphics card: AMD Radeon HD 8370D ATI Technologies Inc. 4.5.13399 Core Profile Context 15.200.1062.1004 **Blender Version** Broken: version: 2.83 (sub 13), branch: master, commit date: 2020-04-08 21:23, hash: `1239cab11f` (Broken in both version 2.83 alpha and 2.83 beta) Worked: 2.82 **Short description of error** When both **X-axis mirror** and **Auto ik** are activated in **Pose mode**, grabbing or rotating a bone **with a mirror opposite bone** (armL and armR for example) then **Disabling X-Axis Mirror** causes **the child of the opposite bone to no longer move when using the grab tool (G).** After that the only way to get Auto IK to behave properly on the frozen bone is to re-enable X-Axis mirror then grab any bone that has no child on opposite side. **Exact steps for others to reproduce the error** **From default startup:** 1 - Create armature with a bone that has both: a child bone and a mirrored bone. For example, a spine with two arms (the parents) with forearms (the childs). 2 - Enable both 'X-Axis Mirror' and 'Auto IK'. 3 - Select a parent mirrored bone, the upper arm in this case, grab it, then move it somewhere or release it, doesn't matter. 4 - Disable X-Axis Mirror, keep Auto IK activated. 4 - The child bone of the mirrored bone, the forearm in this case, is now "frozen". Grabbing it with Auto IK enabled changes it's transform location property values but the bone does not move. It can still be rotated. Disabling Auto IK allows it to be moved again until Auto IK is re-enabled. The only way to unfreeze that bone is to enable both Auto IK and X-Axis Mirror yet again then select a bone that has no child (otherwise you'll freeze another bone), grab it, release it, the disable X-Axis Mirror. The bone can now be grabbed and moved with Auto IK enabled as expected. **From .blend file:** 1 - Grab either forearm.L or hand.L and move it. (Already in Pose mode and Auto IK is enabled) 2 - In 2.83 alpha and beta It/they won't move. They can be moved in 2.82. ( The file includes a rigify rig but the bug has nothing to do with rigify, i've tested with a stock armature ) [blenbug3.blend](https://archive.blender.org/developer/F8477932/blenbug3.blend)

marc commented

2020-04-17 04:59:11 +02:00

Added subscriber: @marcdred

Brecht Van Lommel commented

2020-04-17 14:29:33 +02:00

Added subscriber: @ZedDB

Philipp Oeser commented

2020-04-17 15:38:52 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-04-17 15:38:52 +02:00

Caused by a6a9a12e8f

Caused by a6a9a12e8f

Philipp Oeser commented

2020-04-17 15:54:55 +02:00

Added subscribers: @dr.sybren, @mano-wii

Philipp Oeser commented

2020-04-17 15:54:55 +02:00

This comment was removed by @lichtwerk

*This comment was removed by @lichtwerk*

Philipp Oeser commented

2020-04-17 16:44:52 +02:00

Clearing BONE_TRANSFORM_MIRROR in count_set_pose_transflags will reenable Auto IK (but break autokey), will need to have a look later with fresh eyes...
[that flag has a history in this regard, see b8ca806b77 as well]

Clearing `BONE_TRANSFORM_MIRROR` in `count_set_pose_transflags` will reenable Auto IK (but break autokey), will need to have a look later with fresh eyes... [that flag has a history in this regard, see b8ca806b77 as well]

Philipp Oeser self-assigned this 2020-04-17 17:59:20 +02:00

Philipp Oeser commented

2020-04-17 17:59:20 +02:00

Think I got it, will post during/after the weekend...