Page MenuHome
Create Task
Maniphest T48136

Transformation constraint inconsistent behavior (scale)
Closed, ArchivedPublic
Actions

Description

Blender Version
Possibly all versions?

Short description of error
While working on a project, I discovered an inconsistent behavior in the transformation constraint.

Because drivers have no way of referencing "self" value (as done in After Effects expressions, which is a needed feature, in my opinion) I found myself using the transformation constraint a lot to be able to manually alter a transformation parameter (location/rotation) beyond a driven value.

But that's the thing: I can have control of location and rotation, but not scale. As soon as the scale parameter is set, it's locked unlike location and rotation.

I'm not entirely sure if this would be more akin to a design flaw than a bug, but I thought I'd report just in case (couldn't find a discussion of this anywhere).

Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps

Event Timeline

KiJeon (0o00o0oo) created this task.Apr 13 2016, 11:52 AM
KiJeon (0o00o0oo) raised the priority of this task from to 90.
KiJeon (0o00o0oo) updated the task description. (Show Details)
KiJeon (0o00o0oo) added projects: BF Blender, Animation & Rigging.
KiJeon (0o00o0oo) edited a custom field.
KiJeon (0o00o0oo) added a subscriber: KiJeon (0o00o0oo).
Sergey Sharybin (sergey) lowered the priority of this task from 90 to 30.Apr 13 2016, 1:33 PM
Sergey Sharybin (sergey) added a subscriber: Sergey Sharybin (sergey).

That is really hard to tell if issue you're encountering is a bug or not. Please always attach .blend file which demonstrates the issue you've got.

Currently it's sounds more like a limitation of a constraint which is not really considered a bug.

KiJeon (0o00o0oo) added a comment.Apr 14 2016, 1:01 AM

I'll do you one better than a .blend. Show and tell:

I think that should clearly convey what behavior I was expecting vs. reality. As you can see, the location and rotation are still manually adjustable even when the transformation constraint is set, but scale isn't.
It seems to me the location/rotation function as relative numbers (which is great), but scale functions as absolute.

And I fear you're right about it being a limitation, but.. here's to hoping, haha.

Bastien Montagne (mont29) changed the task status from Unknown Status to Unknown Status.Apr 22 2016, 7:33 PM
Bastien Montagne (mont29) claimed this task.
Bastien Montagne (mont29) added a subscriber: Bastien Montagne (mont29).

Thanks for the report, but this is a known limitation (commented in code), which we cannot address currently because it would break many existing rigs, unfortunately…

KiJeon (0o00o0oo) added a comment.May 2 2017, 11:40 PM

I'm still bumping up against this problem. Are there plans to remedy this limitation in 2.8? Even if it breaks older rigs, I'd be glad to have this limitation removed going forward.

KiJeon (0o00o0oo) added a comment.Nov 20 2017, 8:56 PM

Running into this issue again. Could this be possibly be fixed with the new depsgraph or something?