CommandBuffer.SetViewMatrix

参数

描述

添加一个命令来设置视图矩阵。

视图矩阵是从世界空间转换到相机空间的矩阵。

当设置视图和投影矩阵时，使用SetViewProjectionMatrices 更有效率。

注意：Unity 中的相机空间与 OpenGL 约定一致，因此负 z 轴是相机的朝向。这与 Unity 的常规约定不同，在常规约定中，相机的朝向是正 z 轴。如果您手动创建视图矩阵（例如，使用 Matrix4x4.LookAt 的逆矩阵），则需要将其沿 z 轴缩放 -1 以获得正确的视图矩阵。

using UnityEngine;
using UnityEngine.Rendering;

// Attach this script to a Camera and pick a mesh to render.
// When you enter Play mode, a command buffer renders a green mesh at
// origin position.
[RequireComponent(typeof(Camera))]
public class ExampleScript : MonoBehaviour
{
    public Mesh mesh;

    void Start()
    {
        var material = new Material(Shader.Find("Hidden/Internal-Colored"));
        material.SetColor("_Color", Color.green);

        var tr = transform;
        var camera = GetComponent<Camera>();

        // Code below does the same as what camera.worldToCameraMatrix would do. Doing
        // it "manually" here to illustrate how a view matrix is constructed.
        //
        // Matrix that looks from camera's position, along the forward axis.
        var lookMatrix = Matrix4x4.LookAt(tr.position, tr.position + tr.forward, tr.up);
        // Matrix that mirrors along Z axis, to match the camera space convention.
        var scaleMatrix = Matrix4x4.TRS(Vector3.zero, Quaternion.identity, new Vector3(1, 1, -1));
        // Final view matrix is inverse of the LookAt matrix, and then mirrored along Z.
        var viewMatrix = scaleMatrix * lookMatrix.inverse;

        var buffer = new CommandBuffer();
        buffer.SetViewMatrix(viewMatrix);
        buffer.SetProjectionMatrix(camera.projectionMatrix);
        buffer.DrawMesh(mesh, Matrix4x4.identity, material);

        camera.AddCommandBuffer(CameraEvent.BeforeSkybox, buffer);
    }
}

其他资源：SetProjectionMatrix，SetViewProjectionMatrices，Camera.worldToCameraMatrix，Matrix4x4.LookAt。