Cant add Torque and Rotation to a rigidbody in the same frame?

Questions & Answers
1

Hi guys, could really do with some expert help here as I’m tearing my hair out with this! I cant find any other help articles which address this problem, so hopefully I’m overlooking something very simple.

Basically, I’m writing a top-down helicopter TPS (think Desert Strike). So far its going really well and I have a great model which flies around using proper physics and feels very real.

In each FixedUpdate I’m getting the 3 input axes (pitch, yaw, roll (the axes around x y z respectively)) and then calling my moveplayer method. This applies forces along x and z (y is constrained in the rigidbody settings) and applies a torque around y. So far it works beautifully.

Here’s where the problem starts: I want to tilt the helicopter in the direction of travel, but when I apply any sort of rotation command to x or z to pitch or roll (x or z) it works but the torque command stops working so the player can’t rotate left or right. Where am I going wrong?

Here’s the gist of my code:

	void FixedUpdate ()
	{
			// Get pitch input (-1 to 1)
			float pitch = Input.GetAxis ("Vertical");

			// Get yaw (turn) input (-1 to 1)
			float yaw = Input.GetAxis ("Horizontal");

			// Get roll input (-1 to 1) - Keys Q & A
			float roll = Input.GetAxis ("Roll");

			// Move player
			MovePlayer (pitch, yaw, roll); 
	}


	void MovePlayer (float pitch, float yaw, float roll)
	{
		// move helicopter in pitch direction
		playerRigidbody.AddForce (transform.forward * pitch * thrust);	

		// turn helicopter in yaw direction
		playerRigidbody.AddTorque(transform.up * yaw * 100);

		// move helicopter in roll direction
		playerRigidbody.AddForce (transform.right * roll * thrust);

		//Clamp helicopter speed
		playerRigidbody.velocity = Vector3.ClampMagnitude (playerRigidbody.velocity, maxSpeed);

		// tilt helicopter in pitch direction - enabling this line stops rotation working!
		transform.Rotate (transform.right, pitch*20);
}

I would be VERY grateful if anyone can help me. I’ve certainly had a lot of help from reading existing answers so far.

Cheers,
Dave

2

add all forces and torques together and apply them only once. they get overridden this way.

3

OK, I’ve sussed it myself! Here’s the solution for anyone interested. (There’s certainly nothing out there about this).

	// tilt helicopter 
	pitchRot = pitchInput * 10f; // pitchInput is vertical input axis
	rollRot = rollInput * 10f;  // rollInput is horizontal input axis
	transform.localEulerAngles = new Vector3(Mathf.Clamp (pitchRot, -20, 20), transform.localEulerAngles.y, Mathf.Clamp (-rollRot, -20, 20));

This allows addtorque to be applied around the Y axis.