Insufficient transform precision? #96166

New Issue

Konstantins Visnevskis · 2022-03-04T14:43:15+01:00

2022-03-04 14:43:15 +01:00

System Information
Operating system: Windows-10-10.0.19043-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.39

Blender Version
Broken: version: 3.0.1, branch: master, commit date: 2022-01-25 17:19, hash: dc2d180181

Short description of error
In rigs, and to a lesser degree in geometry itself, there is percievable jiggle in moving objects that are further from world origin.

We are working on an animation feature film, which has lots of open nature scenes. That assumes moderately large object dimensions and distances (1-10 kilometers) in relation to life sized character close-ups. In shots that are not located in the center of the coordinate system there is a visible jiggle in bone locations and resulting geometry. Same jiggle can be seen in plain geometry objects that are further from origin, however in characters it becomes a problem already at a 100m from the world origin, probably due to many layers of transform/parent/constraint relationships multiplying the error.

Insufficient floathing point precision? #90125 might be of same nature but in rotation.
Edit: just to be clear this is about precision of transforms and calculated final world coordinates. Never encountered problems with precision of the stored geometry data.

Exact steps for others to reproduce the error
var.blend
Press play. Vertex motion gets quantized.

**System Information** Operating system: Windows-10-10.0.19043-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.39 **Blender Version** Broken: version: 3.0.1, branch: master, commit date: 2022-01-25 17:19, hash: `dc2d180181` **Short description of error** In rigs, and to a lesser degree in geometry itself, there is percievable jiggle in moving objects that are further from world origin. We are working on an animation feature film, which has lots of open nature scenes. That assumes moderately large object dimensions and distances (1-10 kilometers) in relation to life sized character close-ups. In shots that are not located in the center of the coordinate system there is a visible jiggle in bone locations and resulting geometry. Same jiggle can be seen in plain geometry objects that are further from origin, however in characters it becomes a problem already at a 100m from the world origin, probably due to many layers of transform/parent/constraint relationships multiplying the error. Insufficient floathing point precision? #90125 might be of same nature but in rotation. Edit: just to be clear this is about precision of transforms and calculated final world coordinates. Never encountered problems with precision of the stored geometry data. **Exact steps for others to reproduce the error** [var.blend](https://archive.blender.org/developer/F12897157/var.blend) Press play. Vertex motion gets quantized.

Konstantins Visnevskis commented

2022-03-04 14:43:15 +01:00

Added subscriber: @KonstantinsVisnevskis

Konstantins Visnevskis changed title from ~~Insufficient coordinate precission?~~ to Insufficient transform precision?

2022-03-04 14:44:07 +01:00

Germano Cavalcante commented

2022-03-04 20:22:23 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-03-04 20:22:23 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Germano Cavalcante commented

2022-03-04 20:22:23 +01:00

Looking at the file, this is more of a limitation in the render engines than in the transformation.
This can be confirmed by checking the result of the animation seen in Cycles (which is smoother although not perfect either).
To solve this, maybe Blender should work with projection matrices with double precision instead of single float precision.
But I don't think this is something that can be solved through a simple bug fix. It would be a relatively large project.

So I'm tagging the #eevee_viewport team to define if this is a Bug, Know Issue or another subtype.

Looking at the file, this is more of a limitation in the render engines than in the transformation. This can be confirmed by checking the result of the animation seen in `Cycles` (which is smoother although not perfect either). To solve this, maybe Blender should work with projection matrices with double precision instead of single float precision. But I don't think this is something that can be solved through a simple bug fix. It would be a relatively large project. So I'm tagging the #eevee_viewport team to define if this is a `Bug`, `Know Issue` or another subtype.

Konstantins Visnevskis commented

2022-03-05 02:48:45 +01:00

The file was a geometry example at 10km.
Here's an example of a 2cm eye on a rig at just 500m.
jiggle-test2.blend

The file was a geometry example at 10km. Here's an example of a 2cm eye on a rig at just 500m. [jiggle-test2.blend](https://archive.blender.org/developer/F12897866/jiggle-test2.blend)

Jacob Merrill commented

2022-03-05 18:39:42 +01:00

Added subscriber: @JacobMerrill-1

Jacob Merrill commented

2022-03-05 18:39:42 +01:00

https://www.researchgate.net/publication/331628217_Using_a_Floating_Origin_to_Improve_Fidelity_and_Performance_of_Large_Distributed_Virtual_Worlds

you can solve this with a floating origin*

"Traditional approaches to SJ fall into three classes: on-the-fly shifting of coordinates, subdivision of the world into local coordinate systems and piecewise shifting of world coordinates (WC)"

https://www.researchgate.net/publication/331628217_Using_a_Floating_Origin_to_Improve_Fidelity_and_Performance_of_Large_Distributed_Virtual_Worlds you can solve this with a floating origin* "Traditional approaches to SJ fall into three classes: on-the-fly shifting of coordinates, subdivision of the world into local coordinate systems and piecewise shifting of world coordinates (WC)"

Konstantins Visnevskis commented

2022-03-23 10:58:39 +01:00

For some reason I thought we do, but it turns out we don't have a workaround - if you parent something to an empty to move it back to the origin, the geometry wobble is still there. It seems that we'll have to just move all objects in the scene for each shot, without unified parenting offset, which means not being able to transfer object coordinates between shots.
It seems really strange people don't complain about this, because having life-scale shots in different places of a km size world is not something extraordinary.

For some reason I thought we do, but it turns out we don't have a workaround - if you parent something to an empty to move it back to the origin, the geometry wobble is still there. It seems that we'll have to just move all objects in the scene for each shot, without unified parenting offset, which means not being able to transfer object coordinates between shots. It seems really strange people don't complain about this, because having life-scale shots in different places of a km size world is not something extraordinary.

Philipp Oeser removed the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Insufficient transform precision? #96166