用Unity3d的maxtrix实现的WolrdToScreen

来源：互联网发布：2017年淘宝客市场规模编辑：程序博客网时间：2024/05/18 08:50

最近在使用Unity的转换矩阵的时候，遇到点问题，现在解决了，贴出来，大家有需要的可以拿走

using UnityEngine;

public class CameraTest : MonoBehaviour
{
void Start()
{
Vector3 p0 = new Vector3(0, 12.58f, 10);
Vector3 screenP = Camera.main.WorldToScreenPoint(p0);
Debug.Log(screenP);

Matrix4x4 mvp = Camera.main.projectionMatrix * Camera.main.worldToCameraMatrix;
Vector3 screenP1 = WorldToScreen(mvp, p0, Screen.width, Screen.height);
Debug.Log(screenP1);
}

Vector3 WorldToScreen(Matrix4x4 camMVP, Vector3 point, float renderWidth, float renderHeight)
{
Vector3 result;
result.x = camMVP.m00 * point.x + camMVP.m01 * point.y + camMVP.m02 * point.z + camMVP.m03;
result.y = camMVP.m10 * point.x + camMVP.m11 * point.y + camMVP.m12 * point.z + camMVP.m13;
result.z = camMVP.m20 * point.x + camMVP.m21 * point.y + camMVP.m22 * point.z + camMVP.m23;
float num = camMVP.m30 * point.x + camMVP.m31 * point.y + camMVP.m32 * point.z + camMVP.m33;
float oriNum = num;
num = 1f / num;
result.x *= num;
result.y *= num;
result.z = oriNum; // num contains the 1 / (distance to camera), ideal to linearly interpolate the depth in a rasterizer
point = result;

point.x = (point.x * 0.5f + 0.5f) * renderWidth;
point.y = (point.y * 0.5f + 0.5f) * renderHeight;

return point;
}

}

0 0