Drivers not updating in real time in the viewport when using world or local space for variable on Bones #37431

New Issue

Stanislas Paillereau · 2013-11-14T09:04:39+01:00

2013-11-14 09:04:39 +01:00

System Information
MacOSX

Blender Version
Broken: Blender 2.69

Short description
I hope, this bug doesn't already exist but didn't find something similar in the bug tracker.

Drivers seem to work only when the variable is set to the transform space on any transform channel of a BONE (seems to work well with objects like empty for example).
If the space is set to world or local, I experienced a lag in the viewport when manipulating the driver bone.

Exact steps for others to reproduce the error
1- create an armature (bone 1)
2- duplicate the bone (bone 2), and set a copy location constraint with local or world space.
3- duplicate bone1 once more (create bone3) and add a driver (average value) to one of its channel (x location for example). Set the variable to :

transform channel
ob/bone : Armature, bone2
type : X location
space : world (or local both give the same result)

Now move bone1 in x direction, bone2 and bone3 follow but when using ESC or right click, bone1 and bone2 go back to previous location but bone3 stay in place. Only another action will make it (bone3) goes back to the right location.

The behavior seems to be ok with objects other than bones though (same test with 3 empties worked).

drivers_bug.blend
Thank you,
Stan

**System Information** MacOSX **Blender Version** Broken: Blender 2.69 **Short description** I hope, this bug doesn't already exist but didn't find something similar in the bug tracker. Drivers seem to work only when the variable is set to the transform space on any transform channel of a BONE (seems to work well with objects like empty for example). If the space is set to world or local, I experienced a lag in the viewport when manipulating the driver bone. **Exact steps for others to reproduce the error** 1- create an armature (bone 1) 2- duplicate the bone (bone 2), and set a copy location constraint with local or world space. 3- duplicate bone1 once more (create bone3) and add a driver (average value) to one of its channel (x location for example). Set the variable to : - transform channel - ob/bone : Armature, bone2 - type : X location - space : world (or local both give the same result) Now move bone1 in x direction, bone2 and bone3 follow but when using ESC or right click, bone1 and bone2 go back to previous location but bone3 stay in place. Only another action will make it (bone3) goes back to the right location. The behavior seems to be ok with objects other than bones though (same test with 3 empties worked). [drivers_bug.blend](https://archive.blender.org/developer/F27085/drivers_bug.blend) Thank you, Stan

Stanislas Paillereau commented

2013-11-14 09:04:39 +01:00

Changed status to: 'Open'

Stanislas Paillereau commented

2013-11-14 09:04:39 +01:00

Added subscriber: @StanislasPaillereau

Joshua Leung commented

2013-11-14 13:48:04 +01:00

Changed status from 'Open' to: 'Duplicate'

Joshua Leung closed this issue

2013-11-14 13:48:04 +01:00

Joshua Leung commented

2013-11-14 13:52:45 +01:00

Added subscriber: @JoshuaLeung

Joshua Leung commented

2013-11-14 13:52:45 +01:00

This is a known limitation of the current dependency graph (depsgraph).

Currently, the depsgraph can only represent and schedule up relationships on datablock level. Drivers are actually evaluated on the object level, and all in one go before any other data on the object gets evaluated. As a result, for drivers which operate on bones within the same armature that they read values from, the drivers are only able to see the result of the previous time that the pose was evaluated. In other words, you'll find a bit of lag in the updates.

This can only be fixed when we have a new depsgraph in place. Work is underway to set this up, but for now it isn't quite ready for release yet.

This is a known limitation of the current dependency graph (depsgraph). Currently, the depsgraph can only represent and schedule up relationships on datablock level. Drivers are actually evaluated on the object level, and all in one go before any other data on the object gets evaluated. As a result, for drivers which operate on bones within the same armature that they read values from, the drivers are only able to see the result of the previous time that the pose was evaluated. In other words, you'll find a bit of lag in the updates. This can only be fixed when we have a new depsgraph in place. Work is underway to set this up, but for now it isn't quite ready for release yet.

Stanislas Paillereau commented

2013-11-14 20:05:26 +01:00

Thx algorith for the clarification.
I'll keep a patient eye on it!

Thx algorith for the clarification. I'll keep a patient eye on it!

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Drivers not updating in real time in the viewport when using world or local space for variable on Bones #37431