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Geometry node: Using "Object Info" node create random rotation as we don't have any normal tangent information
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Description

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 452.06

Blender Version
Broken: version: 2.92.0 Beta, branch: master, commit date: 2021-01-26 22:19, hash: rB7d24aa8aa8ca

Short description of error
Scattering objects by using an Object Info node is incompatible with animation if the scattering is using the normal ATTR.
Random rotation occurring with X and Y axis (normal tangent), this behavior is not occurring if we don't use the Object info node for scattering.

This is a really simple/common case, I hope this limitation/issue will be fixed

Gif:

Working :


Causing Issues:

Exact steps for others to reproduce the error
-Scatter from an empty object, and use a sphere as the object of an object info node
-rotation of the sphere will cause random rotation (see example files)

weird orientation.blend2 MBDownload

Event Timeline

NoobiePoopsie (helloidonthaveanyideaformyusername) created this task.Jan 27 2021, 7:06 PM
NoobiePoopsie (helloidonthaveanyideaformyusername) added a project: Geometry Nodes.
NoobiePoopsie (helloidonthaveanyideaformyusername) added a comment.Jan 27 2021, 7:13 PM

Close up

NoobiePoopsie (helloidonthaveanyideaformyusername) renamed this task from Geometry node: Using "Object Info" node create random rotation to Geometry node: Using "Object Info" node create random rotation as we don't have any normal tangent information.Jan 27 2021, 7:59 PM
NoobiePoopsie (helloidonthaveanyideaformyusername) updated the task description. (Show Details)
NoobiePoopsie (helloidonthaveanyideaformyusername) added a comment.EditedJan 28 2021, 1:08 PM

It may be how the object info node is evaluating the transforms.
Maybe a third mode hybrid to Original/relative would do the job? the problem is that the Relative mode is applying the transforms, how about transfer them?

Once the transforms are transferred back to the generated scatter, the problem is fixed. so how about doing that automatically to avoid the confusion?

Philipp Oeser (lichtwerk) changed the task status from Needs Triage to Needs Information from Developers.Feb 26 2021, 5:46 PM
Philipp Oeser (lichtwerk) added subscribers: Jacques Lucke (JacquesLucke), Sebastian Parborg (zeddb), Philipp Oeser (lichtwerk).

I think you've found the solution yourself.
Dont really think this is a bug.

Question remains if there is a simpler way to do this?
I would close this, but let @Sebastian Parborg (zeddb) or @Jacques Lucke (JacquesLucke) comment first.

Hans Goudey (HooglyBoogly) closed this task as Archived.Apr 30 2021, 9:15 PM
Hans Goudey (HooglyBoogly) added a subscriber: Hans Goudey (HooglyBoogly).

Yeah, I don't think this is a bug either. Looking closer at the example, there is a similar "pole" in the box rotation on the backside of the "working" sphere when you rotate it in edit mode, and the sphere from the object info node is basically doing the same thing. There's just no way around converting to local space.

The real solution here is to use some sort of tangent information for the other axis of the rotation. But that's not a bug, just like @Philipp Oeser (lichtwerk) says.

Thanks for the report though, and the clear example file.