How to Properly Disable Sensors in Jolt Physics?

[samaursa]

I'm trying to disable a sensor in Jolt Physics using the following approaches:

RigidBody->SetIsSensor(false); // where RigidBody is a JPH::Body*

and

PhysicsSystem->GetBodyInterface().DeactivateBody(RigidBodyID);

However, neither approach seems to prevent overlaps from occurring.

Here’s the behaviour I’d like to achieve:

1. When a sensor is disabled, it should no longer participate in overlaps with other sensors or rigid bodies.
2. If the sensor is disabled while already overlapping another sensor or rigid body, an "end-overlap" callback should be triggered.

I understand that I can use OnContactValidate combined with custom logic to handle the end-overlap callbacks and ignore any overlaps or end-overlaps reported by Jolt. However, this approach introduces additional overhead. Ideally, I want the sensor to be completely disabled to improve performance.

Is there a built-in way to achieve this behaviour in Jolt, or is my custom logic the only solution?

[jrouwe]

RigidBody->SetIsSensor(false)

This changes the sensor into a normal rigid body so all simulated objects start colliding as if it were a solid object.

PhysicsSystem->GetBodyInterface().DeactivateBody(RigidBodyID)

This makes the sensor go to sleep. For sensors this means it doesn't detect sleeping bodies anymore, but it will still detect active ones.

I understand that I can use OnContactValidate combined with custom logic to handle the end-overlap callbacks and ignore any overlaps or end-overlaps reported by Jolt

Correct.

Is there a built-in way to achieve this behaviour in Jolt, or is my custom logic the only solution?

There are 2 ways:

• Remove the sensor by calling BodyInterface::RemoveBody and re-add it later again with BodyInterface::AddBody.
• Change the collision layer using BodyInterface::SetObjectLayer to a layer that doesn't collide with anything (possibly also in a BroadPhaseLayer that doesn't collide with anything)

In both cases you should get an 'end-overlap' callback during the next PhysicsSystem::Update.