CharacterVirtual controller is flying upwards very fast

[Mahmoud1205]

This is a video of what happens, the character flies immediately after the physics system is enabled (by adding PhysicsSystem::Update and CharacterVirtual::Update to the game loop). https://github.com/user-attachments/assets/f323c240-525c-4017-825a-06e803c25faa
The camera is locked to the CharacterVirtual.

I know that the physics simulation is working correctly because there is a bouncy sphere that is simulating correctly.

Relevant code below

// in the game loop
mPhysicsSystem.Update(inDeltaTime, 1, &mTempAllocator, &mJobSystem);

CharacterVirtual::ExtendedUpdateSettings update_settings;
update_settings.mStickToFloorStepDown = -mCharacterVirtual->GetUp() * update_settings.mStickToFloorStepDown.Length();
update_settings.mWalkStairsStepUp = mCharacterVirtual->GetUp() * update_settings.mWalkStairsStepUp.Length();
mCharacterVirtual->ExtendedUpdate(inDeltaTime,
		         	 -mCharacterVirtual->GetUp() * mPhysicsSystem.GetGravity().Length(),
				  update_settings,
				  mPhysicsSystem.GetDefaultBroadPhaseLayerFilter(Layers::MOVING),
				  mPhysicsSystem.GetDefaultLayerFilter(Layers::MOVING),
				  {},
				  {},
				  mTempAllocator
);

// ran every frame
glm::vec3 movementDirection;

if (glfwGetKey(inWindow, GLFW_KEY_W) == GLFW_PRESS)
	movementDirection = cameraSpeed * mCamera.mFront;
if (glfwGetKey(inWindow, GLFW_KEY_S) == GLFW_PRESS)
	movementDirection = cameraSpeed * mCamera.mFront;
if (glfwGetKey(inWindow, GLFW_KEY_A) == GLFW_PRESS)
	movementDirection = glm::normalize(glm::cross(mCamera.mFront, mCamera.mUp)) * cameraSpeed;
if (glfwGetKey(inWindow, GLFW_KEY_D) == GLFW_PRESS)
	movementDirection = glm::normalize(glm::cross(mCamera.mFront, mCamera.mUp)) * cameraSpeed;

mPhysics.HandleCharacterInput(types::GlmToJph(movementDirection), false, mDeltaTime);
mCamera.mPosition = types::JphToGlm(mPhysics.mCharacterVirtual.GetPtr()->GetPosition());

void Physics::HandleCharacterInput(JPH::Vec3 inMovementDirection, bool inJump, f32 inDeltaTime) {
	bool player_controls_horizontal_velocity = mControlMovementDuringJump || mCharacterVirtual->IsSupported();
	if (player_controls_horizontal_velocity) {
		// Smooth the player input
		mDesiredVelocity = mEnableCharacterInertia ? 0.25f * inMovementDirection * mCharacterSpeed + 0.75f * mDesiredVelocity : inMovementDirection * mCharacterSpeed;

		// True if the player intended to move
		mAllowSliding = !inMovementDirection.IsNearZero();
	} else {
		// While in air we allow sliding
		mAllowSliding = true;
	}

	// Update the character rotation and its up vector to match the up vector set by the user settings
	Quat character_up_rotation = Quat::sEulerAngles(Vec3(mUpRotationX, 0, mUpRotationZ));
	mCharacterVirtual->SetUp(character_up_rotation.RotateAxisY());
	mCharacterVirtual->SetRotation(character_up_rotation);

	// A cheaper way to update the character's ground velocity,
	// the platforms that the character is standing on may have changed velocity
	mCharacterVirtual->UpdateGroundVelocity();

	// Determine new basic velocity
	Vec3 current_vertical_velocity = mCharacterVirtual->GetLinearVelocity().Dot(mCharacterVirtual->GetUp()) * mCharacterVirtual->GetUp();
	Vec3 ground_velocity = mCharacterVirtual->GetGroundVelocity();
	Vec3 new_velocity;
	bool moving_towards_ground = (current_vertical_velocity.GetY() - ground_velocity.GetY()) < 0.1f;
	if (mCharacterVirtual->GetGroundState() == CharacterVirtual::EGroundState::OnGround	// If on ground
		&& (mEnableCharacterInertia ?
		moving_towards_ground													// Inertia enabled: And not moving away from ground
		: !mCharacterVirtual->IsSlopeTooSteep(mCharacterVirtual->GetGroundNormal())))			// Inertia disabled: And not on a slope that is too steep
	{
		// Assume velocity of ground when on ground
		new_velocity = ground_velocity;

		// Jump
		if (inJump && moving_towards_ground)
			new_velocity += mJumpSpeed * mCharacterVirtual->GetUp();
	} else
		new_velocity = current_vertical_velocity;

	// Gravity
	new_velocity += (character_up_rotation * mPhysicsSystem.GetGravity()) * inDeltaTime;

	if (player_controls_horizontal_velocity) {
		// Player input
		new_velocity += character_up_rotation * mDesiredVelocity;
	} else {
		// Preserve horizontal velocity
		Vec3 current_horizontal_velocity = mCharacterVirtual->GetLinearVelocity() - current_vertical_velocity;
		new_velocity += current_horizontal_velocity;
	}

	// Update character velocity
	mCharacterVirtual->SetLinearVelocity(new_velocity);

	// TODO: Stance switch
	/*if (inSwitchStance) {
		bool is_standing = mCharacterVirtual->GetShape() == mStandingShape;
		const Shape* shape = is_standing ? mCrouchingShape : mStandingShape;
		if (mCharacterVirtual->SetShape(shape, 1.5f * mPhysicsSystem->GetPhysicsSettings().mPenetrationSlop, mPhysicsSystem->GetDefaultBroadPhaseLayerFilter(Layers::MOVING), mPhysicsSystem->GetDefaultLayerFilter(Layers::MOVING), { }, { }, *mTempAllocator)) {
			const Shape* inner_shape = is_standing ? mInnerCrouchingShape : mInnerStandingShape;
			mCharacterVirtual->SetInnerBodyShape(inner_shape);
		}
	}*/
}

In the above code snippet, when I log new_velocity this happens

// ran once after jolt physics is initialized
Ref<CharacterVirtualSettings> settings = new CharacterVirtualSettings();
settings->mMaxSlopeAngle = DegreesToRadians(45.0f);
settings->mMaxStrength = 100.0f;
settings->mShape = new CapsuleShape(1.8f, 1.0f);
settings->mBackFaceMode = EBackFaceMode::CollideWithBackFaces;
settings->mCharacterPadding = 0.02f;
settings->mPenetrationRecoverySpeed = 1.0f;
settings->mPredictiveContactDistance = 0.1f;	 // 1.0f is the radius of the capsule's standing shape
settings->mSupportingVolume = Plane(Vec3::sAxisY(), 1.0f); // Accept contacts that touch the lower sphere of the capsule
settings->mEnhancedInternalEdgeRemoval = false;
mCharacterVirtual = new CharacterVirtual(settings, JPH::RVec3(0.0f, 10.0f, 30.0f), JPH::Quat::sIdentity(), 0, &mPhysicsSystem);
mCharacterVirtual->SetListener(&mCharacterContactListener);

I am confused about why this happens because my code looks identical to the CharacterVirtual sample.

[Mahmoud1205]

I fixed it, it was an issue on how I was handling input.