Search Issue Tracker
Fixed in 2022.1.X
Votes
3
Found in
2020.3
2020.3.20f1
2021.1
2021.2
2022.1
Issue ID
1375711
Regression
No
ArticulationBody.maxLinearVelocity doesn't limit velocity when forces are applied to the Articulation Body
How to reproduce:
1. Open the user's attached project
2. Open scene TestScene
3. Press the Play button and observe the Console
Expected result: the logged velocity of each Articulation Body is equal to the applied maximum velocity (1)
Actual result: each Articulation Body reaches the target position immediately before logging movement and the logged velocity is 0
Reproducible with: 2020.3.21f1, 2021.1.27f1, 2021.2.1f1, 2022.1.0a13
Could not test with: 2019.4.32f1 (The type or namespace name 'ArticulationBody' could not be found)
Notes: the Scene contains three test GameObjects, which apply either maxLinearVelocity, maxJointVelocity, or both
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
- ArgumentOutOfRangeException when manipulating the Project Settings search bar
- [Linux] Touch freezes in Player when any mouse button is clicked
- UnityEngine.Rendering.Volume.OnEnable() is called twice before OnDisable() creating multiple copies of the same volume when a volume is enabled right after Domain Reload when entering Play Mode
- Hinge Joint transforms are reset when toggling the "useMotor" property
- Motion Vector texture reports incorrect Mesh data when Mesh is coming from off-screen
Resolution Note (fix version 2022.1):
PhysX Actually limits the velocity, but it does so pre-solver, which means that after the physics simulation step, the velocity may exceed the maximum value.
You can see this in effect if you used smaller values (Body damping/friction 0, Drive damping 1, Drive TargetVelocity 10 and a maxVelocity value of 0.5). The body will increase in speed until reaching 0.5, then it will go to around 0.68 and stay there. PhysX clamps the velocity to 0.5, then the solver increases it afterwards to 0.68.
The intended use for this property is as a fail-safe for huge velocities (where the maxVelocity would be set to a really large value) to save from exploding simulations. To properly limit velocities it would be better to do so by limiting the forces that the Articulation Drive can apply using the Articulation Drive force limit property.
The Documentation will be updated to reflect this functionality.