Precision issue with large distances #74624

New Issue

Peter Baintner · 2020-03-10T16:39:04+01:00

Peter Baintner commented

2020-03-10 16:39:04 +01:00

System Information
Operating system: Win 10
Graphics card: 1080ti{F8399226}

Blender Version
Broken: version: 2.83 (sub 11)
Worked: Never

Short description of error
Unwanted glitches with the use of transparent shader. See picture:

The object with the orange outline is a simple cube with applied scale.

Exact steps for others to reproduce the error

Open attached file
Go to the Rendered view
The camera should already be selected, change the X coordinate to even higher values in order to make the issue more evident.
transparent_shader_refraction.blend

**System Information** Operating system: Win 10 Graphics card: 1080ti{[F8399226](https://archive.blender.org/developer/F8399226/system-info.txt)} **Blender Version** Broken: version: 2.83 (sub 11) Worked: Never **Short description of error** Unwanted glitches with the use of transparent shader. See picture: ![image.png](https://archive.blender.org/developer/F8399223/image.png) The object with the orange outline is a simple cube with applied scale. **Exact steps for others to reproduce the error** - Open attached file - Go to the `Rendered` view The camera should already be selected, change the X coordinate to even higher values in order to make the issue more evident. [transparent_shader_refraction.blend](https://archive.blender.org/developer/F8430512/transparent_shader_refraction.blend)

Peter Baintner commented

2020-03-10 16:39:04 +01:00

Added subscriber: @PeterBaintner

blender-admin commented

2020-03-10 16:39:04 +01:00

#89322 was marked as duplicate of this issue

Peter Baintner commented

2020-03-10 18:56:52 +01:00

I guess the reason is, that the object is too far from origin (719.817 m, -1112.15 m, 222.678 m). So the z-precision of cycles is not enough at this point.

Peter Baintner commented

2020-03-10 18:57:26 +01:00

Changed status from 'Needs Triage' to: 'Archived'

Peter Baintner closed this issue

2020-03-10 18:57:26 +01:00

Peter Baintner commented

2020-03-10 20:35:28 +01:00

Unfortunately scaling this certain scene down does not resolve the issue. Also have a look at the black artefacts on the plane. Those are also coming from missing alpha precision.
Updated version here: https://www.dreisicht.net/share/searchwing/3d/blender/master/master_master_08_bugreport.blend

Unfortunately scaling this certain scene down does not resolve the issue. Also have a look at the black artefacts on the plane. Those are also coming from missing alpha precision. Updated version here: https://www.dreisicht.net/share/searchwing/3d/blender/master/master_master_08_bugreport.blend

Ray molenkamp commented

2020-03-10 20:37:31 +01:00

Changed status from 'Archived' to: 'Needs User Info'

Ray molenkamp reopened this issue

2020-03-10 20:37:31 +01:00

Ray molenkamp commented

2020-03-10 20:37:41 +01:00

Added subscriber: @LazyDodo

Ray molenkamp commented

2020-03-10 20:37:41 +01:00

reopened at request of user

Peter Baintner commented

2020-03-11 01:27:30 +01:00

https://blender.stackexchange.com/questions/128225/how-to-remove-unwanted-refraction-bent-straw-illusion-from-cycles-material

This is another explanation of the problem. Unfortunately without an reply.

https://blender.stackexchange.com/questions/128225/how-to-remove-unwanted-refraction-bent-straw-illusion-from-cycles-material This is another explanation of the problem. Unfortunately without an reply.

Ray molenkamp commented

2020-03-11 05:17:37 +01:00

Have not looked at your file, but the stackexchange post is a classic floating point precision issue.

As the integer part of the number gets bigger, you have less storage available to store the fractional part, it's not as much a bug in cycles as just the way computers deal with fractional numbers.

Have not looked at your file, but the stackexchange post is a [classic floating point precision issue. ](https://blog.demofox.org/2017/11/21/floating-point-precision/) As the integer part of the number gets bigger, you have less storage available to store the fractional part, it's not as much a bug in cycles as just the way computers deal with fractional numbers.

Peter Baintner commented

2020-03-11 09:32:58 +01:00

Yes I am aware of precision errors. Just too bad scaling doesn't help. So the only workaround would be to leave the camera in the origin and move everything else?

But still - 700m fur such an error is very unexpected in my opinion.

Yes I am aware of precision errors. Just too bad scaling doesn't help. So the only workaround would be to leave the camera in the origin and move everything else? But still - 700m fur such an error is very unexpected in my opinion.

Ankit Meel changed title from ~~Transparent shader glitch~~ to Precision issue with large distances

2020-03-26 09:57:39 +01:00

Ankit Meel commented

2020-03-26 09:57:39 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Germano Cavalcante commented

2020-03-27 15:08:04 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-03-27 15:08:04 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Germano Cavalcante commented

2020-03-27 15:08:04 +01:00

The scenario described is too time consuming for us to track down, we require the bug reporter to narrow down the problem.

Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly.

The scenario described is too time consuming for us to track down, we require the bug reporter to narrow down the problem. Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly.

Peter Baintner commented

2020-03-27 15:20:53 +01:00

Here is a very much simplified version: transparent_shader_refraction.blend
Steps to produce this file: create a cylinder, and a cube. Cube gets transparent shader, Move all the objects including the camera 800m from the origin, and you get unwanted refraction.

Here is a very much simplified version: [transparent_shader_refraction.blend](https://archive.blender.org/developer/F8430477/transparent_shader_refraction.blend) Steps to produce this file: create a cylinder, and a cube. Cube gets transparent shader, Move all the objects including the camera 800m from the origin, and you get unwanted refraction.

Germano Cavalcante commented

2020-03-27 15:50:22 +01:00

Changed status from 'Needs User Info' to: 'Confirmed'

Germano Cavalcante commented

2020-03-27 15:53:09 +01:00

Added subscriber: @brecht

Germano Cavalcante commented

2020-03-27 15:53:09 +01:00

I believe this is a known limitation due to float precision.
@brecht, what do you think?

I believe this is a known limitation due to float precision. @brecht, what do you think?

Vlad Kuzmin commented

2020-04-14 10:36:40 +02:00

Added subscriber: @ssh4

Vlad Kuzmin commented

2020-04-14 10:36:40 +02:00

Have same issue in Eevee, and had some reports from 3D scannig studios about limited ability of Blender working with Geo referenced data.
Definitely Blender lack of float precision.

Is there are any idea how hard can be increase Blender precision for better support of real world or georeferenced data?

Have same issue in Eevee, and had some reports from 3D scannig studios about limited ability of Blender working with Geo referenced data. Definitely Blender lack of float precision. Is there are any idea how hard can be increase Blender precision for better support of real world or georeferenced data?

Evan Wilson commented

2021-06-21 13:28:59 +02:00

Added subscriber: @zickkie

Arthur Shapiro commented

2021-06-21 13:44:43 +02:00

Have that problem with IK chains. And "large distance" itself is a quite relative term. Because IK starts to inexplicably jiggle being moved (depends on rig) at, for example, just 100 meters from zero location.IK_bug_when_far_away.blend
In the atached file you can just rotate Root bone and you'll see IK bones jiggling.

Have that problem with IK chains. And "large distance" itself is a quite relative term. Because IK starts to inexplicably jiggle being moved (depends on rig) at, for example, just 100 meters from zero location.[IK_bug_when_far_away.blend](https://archive.blender.org/developer/F10186209/IK_bug_when_far_away.blend) In the atached file you can just rotate Root bone and you'll see IK bones jiggling.

Thomas Dinges commented

2022-11-24 16:51:01 +01:00

Added subscriber: @ThomasDinges

Thomas Dinges commented

2022-11-24 16:51:01 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Thomas Dinges closed this issue

2022-11-24 16:51:01 +01:00

Thomas Dinges self-assigned this 2022-11-24 16:51:01 +01:00

Thomas Dinges commented

2022-11-24 16:51:01 +01:00

Cannot confirm this report anymore, with Blender 3.4.

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Precision issue with large distances #74624