unity矩阵变换

用来可视化了解各种矩阵变换的代码。直接创建即可用。代码注释完整

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

#if UNITY_EDITOR

using UnityEditor;

#endif

public class CoordinateSystem : MonoBehaviour

{

public Transform RedPoint;

public Transform BluePoint;

public Camera ccamera;

public Transform transformCamera;

public Transform transformModel;

public Transform transformWorld;

public Color[] cameraSystemColor;

public Color[] worldSystemColor;

public Color[] modelSystemColor;

public void OnDrawGizmos()

{

//世界空间坐标系

DrawACoordinate(transformWorld, worldSystemColor);

//摄像机空间坐标系

DrawACoordinate(transformCamera,cameraSystemColor);

//模型空间坐标系

DrawACoordinate(transformModel, modelSystemColor);

}

private void DrawACoordinate(Transform inT,Color[] DrawColor)

{

Gizmos.color = DrawColor[0];

Gizmos.DrawLine(inT.position, inT.position + inT.forward);

Gizmos.color = DrawColor[1];

Gizmos.DrawLine(inT.position, inT.position + inT.up);

Gizmos.color = DrawColor[2];

Gizmos.DrawLine(inT.position, inT.position + inT.right);

}

public void CreateModelToWorldMatrix()

{

Matrix4x4 mMatrix = Matrix4x4.TRS(transformModel.position, transformModel.rotation, transformModel.lossyScale);

Debug.Log(transformModel.localToWorldMatrix.ToString() + "\n\n"+mMatrix.ToString());

//取模型空间的原点，转移到世界坐标系中

RedPoint.position = mMatrix *new Vector4(0, 0, 0, 1);

}

public void CreateWorldToCameraMatrix()

{

//将世界坐标的摄像机信息构建一个变换矩阵

//需要注意的是，Z方向的轴向是反的，这是因为

//camera space matches OpenGL convention: camera's forward is the negative Z axis.

//This is different from Unity's convention, where forward is the positive Z axis.

//OpenGL和unity在Z轴的正方定义是相反的

Matrix4x4 cMatrix = Matrix4x4.TRS(transformCamera.position,transformCamera.rotation,new Vector3(1,1,-1));

//计算这个摄像机的逆

cMatrix = Matrix4x4.Inverse(cMatrix);

Debug.Log(ccamera.worldToCameraMatrix.ToString() + "\n\n" + cMatrix.ToString());

Vector3 cameraPosition = cMatrix * new Vector4(RedPoint.position.x, RedPoint.position.y, RedPoint.position.z, 1.0f);

BluePoint.localPosition = new Vector3(cameraPosition.x, cameraPosition.y,cameraPosition.z*-1);

Debug.Log("红点在摄像机空间的坐标为" + BluePoint.localPosition.ToString());

}

public void CreateProjectionMatrix()

{

//Debug.Log(ccamera.projectionMatrix.ToString() + "\n\n"

Matrix4x4 pMatrix = Matrix4x4.Perspective(ccamera.fieldOfView, ccamera.aspect, ccamera.nearClipPlane, ccamera.farClipPlane);

Vector3 bl = BluePoint.localPosition;

Vector3 screenPosition = pMatrix * new Vector4(bl.x, bl.y, bl.z, 1.0f);

screenPosition.Normalize();

Vector2 v2ScreenPosition = new Vector2(screenPosition.x*0.5f+0.5f, screenPosition.y*0.5f+0.5f);

Debug.Log(ccamera.projectionMatrix + "\n\n" + pMatrix.ToString());

Debug.Log("红点在投影后的坐标为" + v2ScreenPosition.ToString());

Debug.Log(ccamera.WorldToViewportPoint(BluePoint.position));

}

}

#if UNITY_EDITOR

[CustomEditor(typeof(CoordinateSystem))]

public class CoordinateSystemEditor : Editor

{

public override void OnInspectorGUI()

{

DrawDefaultInspector();

CoordinateSystem myScript = (CoordinateSystem)target;

if (GUILayout.Button("重置"))

{

myScript.RedPoint.position = Vector3.zero;

myScript.BluePoint.localPosition = Vector3.zero;

}

if (GUILayout.Button("将一个顶点从本地坐标系转换到世界坐标系"))

{

myScript.CreateModelToWorldMatrix();

}

if (GUILayout.Button("将一个顶点从世界坐标系转换到视空间坐标系"))

{

myScript.CreateWorldToCameraMatrix();

}

if (GUILayout.Button("将一个视空间坐标系的内容投影到2D平面上"))

{

myScript.CreateProjectionMatrix();

}

}

}

#endif