Search Issue Tracker
Won't Fix
Votes
0
Found in
2017.4.0f1
2018.4.0f1
2019.1.0f2
2019.2.0a1
2019.3.0a1
2020.1.0a1
Issue ID
1188463
Regression
No
Setting Transform.position of a child GameObject to its own Transform.position sets it imprecisely
How to reproduce:
1. Open user-submitted project (ObjectDrifting.zip)
2. Open the 'ObjectDrift' scene
3. Enter Play Mode
4. Select the Parent/Drifting Object in the Hierarchy window
Expected result: the transform position of the child object does not change
Actual result: the transform position of the child object slowly changes
Reproducible with: 2017.4.32f1, 2018.4.10f1, 2019.2.8f1, 2019.3.0b5, 2020.1.0a7
Notes:
Does not affect GameObjects without a parent GameObject
Add comment
All about bugs
View bugs we have successfully reproduced, and vote for the bugs you want to see fixed most urgently.
Latest issues
- Crash on Umbra::QueryExt::queryStaticShadowCasters when opening a specific project
- Crash on GfxDeviceD3D12Base::DrawBuffersCommon when opening a specific project
- Shader variants are recompiled while Building when the Platform is switched and changed back after the first Build
- Crash on memcpy when importing lightmaps after GI bake
- NullReferenceException is thrown when creating the TextMeshPro component and entering the Play Mode without importing TMP Essentials
Resolution Note:
This is a result of floating point precision errors when calculating the global position of a child object.
When setting or retrieving the global position it has to be calculated from the local position as it is not stored.
The assignment here causes a call to get position and set position of the transform, each of which has a small level of inaccuracy. The rotation of the parent amplifies the issue.
We suggest setting the local position of child object with transform.localPosition where possible. Global positioning of child objects will always require more calculation overhead therefore potential floating point imprecision.