Physics rigid bodies, Pendulum Instances

Questions
1

In learning physics engines, I cannot determine if there is a bug or it`s my question.

In official cases，it is very normal

new BABYLON.PhysicsAggregate(box, BABYLON.PhysicsShapeType.BOX, { mass: 1 }, scene);

:grinning:
I am trying to use my own understanding to implement this case study.
Firstly I implemented it on PG, the hpBodyId property reported an error
image

and then， I implement this function in a local environment,
I tried debugging and didn’t find the problem about the hpBodyId, It does indeed have value

image
image946×710 47.8 KB

But my experiment was also unsuccessful，the second parameter instanceIndex of setMotionType and setMassProperties did not fulfill its intended function

// this.mesh.physicsBody?.setMotionType(BABYLON.PhysicsMotionType.DYNAMIC, 0)
// this.mesh.physicsBody?.setMassProperties({ mass: 1 }, 0)

this.mesh.physicsBody?.setMotionType(BABYLON.PhysicsMotionType.DYNAMIC, 1)
this.mesh.physicsBody?.setMassProperties({ mass: 1 }, 1)
3

I think I see what’s going wrong.
1 box and 1 physics body are created and then instances are added 1 by 1.
But the physics is not updated to take these new instances.
I’d suggest to add the mesh and all its instances and then to create the physics body.

1 Like
4

In this case, the first instance is stationary, and the following instances can oscillate

first instance set

this.mesh.physicsBody?.setMotionType(BABYLON.PhysicsMotionType.STATIC, 0)
this.mesh.physicsBody?.setMassProperties({ mass: 0 }, 0)

other instance set

this.mesh.physicsBody?.setMotionType(BABYLON.PhysicsMotionType.DYNAMIC, 1)
this.mesh.physicsBody?.setMassProperties({ mass: 1 }, 1)

Implementing different instances of the same object exhibit different physical properties (setMassProperties and setMotionType)

5

you are right :kissing_heart:
At first, I didn’t understand. I tried as you told me, and there was no problem
there is a sequence of setting between objects and physical body

1 Like