触摸旋转和缩放3D模型

using UnityEngine;
using System.Collections;

public class SmoothController : MonoBehaviour
{
public Transform Target = null;
public Camera MainCamera = null;

private float XAngle = 0f;
private float YAngle = 0f;
private float XSpeed = 250f;
private float YSpeed = 120f;

private float Distance = 50f;
private float DisSpeed = 10f;
private float MinDistance = 0f;
private float MaxDistance = 50f;

private Vector2 Vec2Pos1 = Vector2.zero;
private Vector2 Vec2Pos2 = Vector2.zero;

void Start()
{
MainCamera = Camera.main;
}

void OnGUI()
{
if (GUI.Button(new Rect(0f, 0f, 100f, 50f), "ReSet"))
{
Distance = 50f;
Target.transform.rotation = Quaternion.identity;
}
}

void Update()
{
if (Input.touchCount == 1)
{
if (Input.GetTouch(0).phase == TouchPhase.Moved)
{
XAngle += Input.GetAxis("Mouse X") * XSpeed * 0.02f;
YAngle -= Input.GetAxis("Mouse Y") * YSpeed * 0.02f;
}
}

if (Input.touchCount > 1)
{
if (Input.GetTouch(1).phase == TouchPhase.Began)
{
Vec2Pos1 = Input.GetTouch(0).position;
Vec2Pos2 = Input.GetTouch(1).position;
}
else if (Input.GetTouch(0).phase == TouchPhase.Moved || Input.GetTouch(1).phase == TouchPhase.Moved)
{
var tempPosition1 = Input.GetTouch(0).position;
var tempPosition2 = Input.GetTouch(1).position;

float deltaDis = DeltaDistance(Vec2Pos1, Vec2Pos2, tempPosition1, tempPosition2);
// 如果在扩大
if (deltaDis < 0f)
Distance += deltaDis * DisSpeed;
else
Distance += deltaDis * DisSpeed;

// 记录旧的位置
Vec2Pos1 = tempPosition1;
Vec2Pos2 = tempPosition2;
}
}

}

void LateUpdate()
{
// 旋转的更新
ClampXY();
Target.transform.Rotate(-YAngle, -XAngle, 0f, Space.World);
XAngle = 0f;
YAngle = 0f;

// 摄像机位置的更新
ClampDistance();
Vector3 cameraPos = MainCamera.transform.position;
cameraPos.z = -Distance;
MainCamera.transform.position = cameraPos;
}

bool IsEnlarge(Vector2 oP1, Vector2 oP2, Vector2 nP1, Vector2 nP2)
{
float leng1 = Mathf.Sqrt((oP1.x - oP2.x) * (oP1.x - oP2.x) + (oP1.y - oP2.y) * (oP1.y - oP2.y));
float leng2 = Mathf.Sqrt((nP1.x - nP2.x) * (nP1.x - nP2.x) + (nP1.y - nP2.y) * (nP1.y - nP2.y));
if (leng1 < leng2)
return true;
else
return false;
}

float DeltaDistance(Vector2 oP1, Vector2 oP2, Vector2 nP1, Vector2 nP2)
{
float leng1 = Mathf.Sqrt((oP1.x - oP2.x) * (oP1.x - oP2.x) + (oP1.y - oP2.y) * (oP1.y - oP2.y));
float leng2 = Mathf.Sqrt((nP1.x - nP2.x) * (nP1.x - nP2.x) + (nP1.y - nP2.y) * (nP1.y - nP2.y));
return leng1 - leng2;
}

void ClampXY()
{
if (XAngle < -360)
XAngle += 360;
if (XAngle > 360)
XAngle -= 360;
if (YAngle < -360)
YAngle += 360;
if (YAngle > 360)
YAngle -= 360;
}

void ClampDistance()
{
Distance = Mathf.Clamp(Distance, MinDistance, MaxDistance);
}

}