CommandBuffer.SetViewMatrix

参数

描述

添加用于设置视图矩阵的命令。

视图矩阵是从世界空间变换为摄像机空间的矩阵。

在设置视图和投影矩阵时，使用 SetViewProjectionMatrices 会更加高效。

注意：Unity 中的摄像机空间遵守 OpenGL 约定，因此负 z 轴是摄像机前方。这 与通常的 Unity 约定不同，在 Unity 中，摄像机前方为正 z 轴。如果 手动创建视图矩阵（例如使用 Matrix4x4.LookAt 的逆矩阵），则需要 沿 z 轴将它缩放 -1，以获取正确的视图矩阵。

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);
    }
}

另请参阅：SetProjectionMatrix、SetViewProjectionMatrices、Camera.worldToCameraMatrix、Matrix4x4.LookAt。