koobas.hobune.stream
Projectile Trajectory Precision
I wrote a script to calculate the trajectory of an arrow firing from the player. I have a gameobject, as a child inside the player, to indicate where the missile fires from. I get it's destination with Camera.main.ScreenToWorldPoint(Input.mousePosition).
Vector2 direction = Camera.main.ScreenToWorldPoint(Input.mousePosition);
utilities.SetTrajectoryPoints(trajectoryDotsCache.transform.position, direction, trajectoryDots.ToArray());
Then, I call a Trajectory Calculator and it takes the origin and destination positions and draws a sequence of green dots to draw the path from A to B.
public Vector2 SetTrajectoryPoints(Vector2 posStart, Vector2 direction, Transform[] trajectoryDots)
{
//Debug.Log(direction.y);
//float magX = (posStart - direction).magnitude * ((direction.x > 0) ? 1 : -1);
//float magY = magX * ((direction.y > 0) ? 1 : -1);
float finalX = direction.x;
float finalY = direction.y;
//Velocity(u) = Mathf. Sqrt((x * x) + (y * y));
float velocity = Mathf.Sqrt((finalX * finalX) + (finalY * finalY));
//Angle = Mathf.Atan2(y, x);
float angle = Mathf.Rad2Deg * (Mathf.Atan2(finalY, finalX));
float tTime = .1f;
Vector2 pos = Vector2.zero;
for(int i=0;i<10;i++)
{
float dx = velocity * tTime * Mathf.Cos(angle * Mathf.Deg2Rad);
float dy = velocity * tTime * Mathf.Sin(angle * Mathf.Deg2Rad) + (Physics2D.gravity.magnitude * tTime * tTime / 2f);
pos = new Vector2(posStart.x - dx, posStart.y - dy);
if (trajectoryDots != null)
{
Transform dot = trajectoryDots[i];
dot.position = pos;
dot.gameObject.SetActive(true);
dot.eulerAngles = new Vector3(0, 0, Mathf.Atan2(finalY - (Physics.gravity.magnitude) * tTime, finalX) * Mathf.Rad2Deg);
}
tTime += .1f;
//Debug.Log(pos);
}
return pos;
}
In the example below, note the green dots stretch off into the distance. What I want is for the calculated arch to reach where the red mark is located in the picture (this is an indication of where the mouse click happened). 
