Describe the bug. Describe what is happening when the bug occurs. Describe what you would normally expect to occur.
HingeConstraint with ActuatorType set to Motor will spin in random and erratic motions when connected to a PrismaticConstraint in a simple configuration. I would expect the HingeConstraint to apply a consistent rotational velocity to the free part that it is attached to.
How often does the bug happen (Everytime/sometimes/rarely)? What are the steps that reproduce the bug? Please list them in very high detail. Provide simple example places that exhibit the bug and provide description of what you believe should be the behavior.
Frequency: Everytime
Steps to reproduce (starting from Studio):
- Create three parts that will be referred to as “A”, “B”, and “C”. Set all parts to CanCollide false. EDIT: Set part B size to [2,0.5,0.5] and part C size to [1,10,10].
- Anchor part A and add an attachment whose Orientation is set to [0, 0, 90]
- Position part B 5 studs below part A and add an attachment whose Orientation is set to [0,0, 90]
- Add a PrismaticConstraint with LimitsEnabled=true, LowerLimit=-5, UpperLimit=0. Set Attachment0 to the attachment created in step 2 and Attachment1 to the attachment created in step 3.
- Add a second attachment to part B with default properties.
- Position part C in the same location as part B and add an attachment with default properties.
- Add a HingeConstraint with AngularVelocity=0.5, MotorMaxTorque=1e5. Set Attachment0 to the attachment created in step 5 and Attachment1 to the attachment created in step 6.
- Press play
Actual Behaviour: Part C bobbles back and forth randomly. GIF below.
Expected Behaviour: Part C rotates at a constant speed.
Where does the bug happen (www, gametest, etc) Is it level-specific? Is it game specific? Please post a link to the place that exhibits the issue.
Not specific to any level/game. Happens on www.roblox.com.
Link to place that exhibits the issue: https://www.roblox.com/games/4538462277/Hinge-and-Prismatic-Bad-Interaction
Would a screenshot or video help describe it to someone? If so, post one.
Anything else that you would want to know about the bug if it were your job to find and fix it.
- Part B does not rotate while part C rotates, therefore PrismaticConstraint is applying itself correctly
- Anchoring part B in the steps to reproduce will cause the HingeConstraint to rotate part C correctly.