Simulating beer pong physics in Unity

This is fun! The trajectory is just a bunch of mathfz and a line renderer. Check out this post for more information on that which details how to calculate the trajectory. Line renderers are definitely your best bet for visualization. Even on mobile, 5-10 line renderers would be no problem. The alternative would be to hard-code the visualization with a (code-created) mesh or directly rendering to the screen, both of which are not fun.

As for physics, I bet you can use Unity's PhysX out of the box. You'll have to play with the initial force to apply but the direction should be about the direction the camera is facing. All you have to do is multiply by some factor to get it working well.

float X = 10; PongBall.rigidbody.AddForce(Camera.main.transform.forward * X, ForceMode.VelocityChange); 

So I started writing some code for you. Then when I tested it, it didn't have the desired result. Here is the code so far. If anyone know what is wrong with it, do tell :-)

/// <summary> /// Adds the velocity to simulate throwing a ball /// </summary> /// <param name="angle">The angle of the throw along the z axis</param> /// <param name="direction">The degrees of the throw to the left or right</param> /// <param name="power">The power of the throw</param> private void ThrowBall(float angle, float direction, float power) { angle = Mathf.Max(Mathf.Min(0, angle), 90); //Make sure angle is between 0 and 90 direction = Mathf.Max(Mathf.Min(-45, direction), 45); //Make sure direction is between -45 and 45 power = Mathf.Max(1, power); //Make sure there is a power of at least 1 angle *= Mathf.Deg2Rad; //Convert angle to radians float xForce = Mathf.Cos(angle) * Mathf.Sin(direction); //Get the force to apply to the x axis to throw the ball to the left or right float yForce = Mathf.Sin(angle); //Get the force to apply to the y axis based on the angle float zForce = Mathf.Cos(angle) * Mathf.Cos(direction); //Get the force to apply to the z axis based on the angle Vector3 force = new Vector3(xForce, yForce, zForce).normalized; //Get the force in a Vector3 and normalize it so that the angle does not affect the power GetComponent<Rigidbody>().AddForce(force * power); //Get the Rigidbody Component and apply the force to it based on the angle and power } 

It works if throwing in a straight line, but when adding a left/right directional force, it raises faster than it moves forward. I am very interested in finding an answer to this. I am going to keep looking, and I will update the code as I find out more information.

As for the trail, I would just add particles behind it.