分别改动Cube每一个面的贴图UV（Unity3D开发之十八）

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原文地址: http://blog.csdn.net/cocos2der/article/details/46611169

今天项目中须要改动一个Cube中每一个面的贴图UV。也就是贴图中有多个矩形贴图。须要程序从贴图中读取一部分赋值给Cube每一个面。

这里已经有人实现了。

CustomUVS.cs

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
public class CustomUVS : MonoBehaviour {
public Vector2 topPoint;
public Vector2 bottomPoint;
public Vector2 leftPoint;
public Vector2 rightPoint;
public Vector2 frontPoint;
public Vector2 backPoint;

private Mesh m_mesh;
public enum CubeFaceType
{
Top,
Bottom,
Left,
Right,
Front,
Back
};

// Use this for initialization
void Start () {
MeshFilter meshFilter = GetComponent<MeshFilter>();
if (meshFilter == null) {
Debug.LogError("Script needs MeshFilter component");
return;
}

#if UNITY_EDITOR
Mesh meshCopy = Mesh.Instantiate(meshFilter.sharedMesh) as Mesh;    // Make a deep copy
meshCopy.name = "Cube";
m_mesh = meshFilter.mesh = meshCopy;                                // Assign the copy to the meshes
#else
m_mesh = meshFilter.mesh;
#endif
if (m_mesh == null || m_mesh.uv.Length != 24) {
Debug.LogError("Script needs to be attached to built-in cube");
return;
}

UpdateMeshUVS();
}

// Update is called once per frame
void Update ()
{
#if UNITY_EDITOR
UpdateMeshUVS();
#endif
}

void UpdateMeshUVS()
{
Vector2[] uvs = m_mesh.uv;
// Front
SetFaceTexture(CubeFaceType.Front, uvs);
// Top
SetFaceTexture(CubeFaceType.Top, uvs);
// Back
SetFaceTexture(CubeFaceType.Back, uvs);
// Bottom
SetFaceTexture(CubeFaceType.Bottom, uvs);
// Left
SetFaceTexture(CubeFaceType.Left, uvs);
// Right
SetFaceTexture(CubeFaceType.Right, uvs);
m_mesh.uv = uvs;
}

Vector2[] GetUVS(float originX, float originY)
{
Vector2[] uvs = new Vector2[4];
uvs[0] = new Vector2(originX / 3.0f, originY / 3.0f);
uvs[1] = new Vector2((originX + 1) / 3.0f, originY / 3.0f);
uvs[2] = new Vector2(originX / 3.0f, (originY + 1) / 3.0f);
uvs[3] = new Vector2((originX + 1) / 3.0f, (originY + 1) / 3.0f);
return uvs;
}

void SetFaceTexture(CubeFaceType faceType, Vector2[] uvs)
{
if (faceType == CubeFaceType.Front) {
Vector2[] newUVS = GetUVS(frontPoint.x, frontPoint.y);
uvs[0]  = newUVS[0];
uvs[1]  = newUVS[1];
uvs[2]  = newUVS[2];
uvs[3]  = newUVS[3];
}else if (faceType == CubeFaceType.Back) {
Vector2[] newUVS = GetUVS(backPoint.x, backPoint.y);
uvs[10] = newUVS[0];
uvs[11] = newUVS[1];
uvs[6]  = newUVS[2];
uvs[7]  = newUVS[3];
}else if (faceType == CubeFaceType.Top) {
Vector2[] newUVS = GetUVS(topPoint.x, topPoint.y);
uvs[8] = newUVS[0];
uvs[9] = newUVS[1];
uvs[4]  = newUVS[2];
uvs[5]  = newUVS[3];
}else if (faceType == CubeFaceType.Bottom) {
Vector2[] newUVS = GetUVS(bottomPoint.x, bottomPoint.y);
uvs[12] = newUVS[0];
uvs[14] = newUVS[1];
uvs[15]  = newUVS[2];
uvs[13]  = newUVS[3];
}else if (faceType == CubeFaceType.Left) {
Vector2[] newUVS = GetUVS(leftPoint.x, leftPoint.y);
uvs[16] = newUVS[0];
uvs[18] = newUVS[1];
uvs[19]  = newUVS[2];
uvs[17]  = newUVS[3];
}else if (faceType == CubeFaceType.Right) {
Vector2[] newUVS = GetUVS(rightPoint.x, rightPoint.y);
uvs[20] = newUVS[0];
uvs[22] = newUVS[1];
uvs[23]  = newUVS[2];
uvs[21]  = newUVS[3];
}
}
}

使用的贴图



给一个Cube加入改图片材质。

并加入CustomUVS.cs脚本。改动须要截取的区域原点



注意：因为图片是3x3的。所以截取区域中按3等分截取。

实际效果