TPCameraAngleSnap.cs

//TPCameraAngleSnap.cs
//Script By Thomas Rasor

using UnityEngine;
using System.Collections;

public class TPCameraAngleSnap : MonoBehaviour
{
    public Transform target;
    public float distance,height,speed,angleIncrement=45f;
    public bool smoothRotate;

    //Here we store private variable for each variable we want to smoothly transition
    //Variables have two versions, [c]urrent and [w]anted
    private Vector3 cPos,wPos;
    private float cDist,wDist,cYRot,wYRot;

    void Start ()
    {
        //Set the wanted distance to the distance from the inspector panel.
        wDist = distance;
    }//End Start

    void Update ()
    {
        //Here we just check for Inputs and wrap the new wanted y rotation values around 360 degrees
        if (Input.GetKeyDown(KeyCode.LeftArrow))
            wYRot = Mathf.Repeat(wYRot-angleIncrement,360f);
        if (Input.GetKeyDown(KeyCode.RightArrow))
            wYRot = Mathf.Repeat(wYRot+angleIncrement,360f);

        if (smoothRotate)
        {
            //Here's where we smooth the rotation and position values IF smoothRotate is true
            cYRot = Mathf.LerpAngle(cYRot,wYRot,Time.deltaTime*speed);
            cPos = Vector3.Lerp(cPos,wPos,Time.deltaTime*speed);
        }
        else
        {
            //Otherwise we just set the current rotation and position to the wanted rotation and position
            cYRot = wYRot;
            cPos = wPos;
        }

        //We always smooth the distance but you might not want to, if that is the case just do this as above
        cDist = Mathf.Lerp(cDist,wDist,Time.deltaTime*speed);

        //Here we calculate the new position using the formula used to get a point on the circumference of a
        //circle:
        //x = cos(angle * (PI/180)) + origin.x;
        //z = sin(angle * (PI/180)) + origin.z;
        wPos.x = (cDist * Mathf.Cos(cYRot * Mathf.PI / 180f)) + target.position.x;
        wPos.z = (cDist * Mathf.Sin(cYRot * Mathf.PI / 180f)) + target.position.z;
        //And then set the wanted y position to the height
        wPos.y = target.position.y + height;

        //Here we actually apply the calculations to the object's/camera's transform
        transform.position = cPos;
        //This just rotates the camera to look at target.position. We could do this other ways for more
        //custom rotation, but this works for this senario.
        transform.LookAt(target.position);
    }//End Update
}//End TPCameraAngleSnap