团结：将球朝桌扇的前进方向移动

Question

I am creating a VR application in which I have a tablefan and a ball with rigidbodies and colliders attached to them. I want the ball to fly in a semicircle when it collides with the fan. I have done this by writing the following 2 lines in my code:

Vector3 dir = Quaternion.AngleAxis(30, Vector3.forward) * Vector3.right;
rigidbody.AddForce(dir*hoverForce, ForceMode.Impulse);

This works fine but the ball flies just in one direction. Could someone please help me understand how to find where is the fan facing and make the ball fly in the forward direction to the fan's rotation?

If I use forward direction on fan's transform in Addforce, then the ball flies in a straight direction instead of at an angle.

Answer 1

Vector3 dir = Quaternion.AngleAxis(30, Vector3.forward) * Vector3.right;

the direction is constant vector here thats why its fly always in same direction. you have to include transform directions in this calculation to calculate the direction according to the transform

may be

Vector3 dir = Quaternion.AngleAxis(30, Vector3.forward) * rigidbody.transform.right;

Answer 2

In order to launch the ball exactly in the direction that the fan is pointing, you need to overwrite any current velocity that the ball has. For that, you can just assign to the ball's Rigidbody.velocity . Otherwise, the ball will still maintain any left-right velocity, and it can launch at a bit of an angle

You can get the direction the fan is facing with fan.transform.forward , and if you want to immediately send the ball flying in that exact direction, then you can just set the velocity directly using that direction times however fast you'd like it to go:

Rigidbody ballRB;     // given
GameObject fan;       // given
float fanLaunchSpeed; // given
ballRB.velocity =     fanLaunchSpeed * fan.transform.forward;

If you want to also add some degrees of elevation, then you can multiply that direction by Quaternion.AngleAxis(angle, fan.transform.right) :

Rigidbody ballRB;     // given
GameObject fan;       // given
float fanLaunchSpeed; // given
float angle;          // given, measured in degrees
Vector3 launchDirection = Quaternion.AngleAxis(angle, fan.transform.right) 
                          * fan.transform.forward;
ballRB.velocity = fanLaunchSpeed * launchDirection;