RenderTexture.active

描述

当前活动的渲染纹理。

所有渲染都进入活动 RenderTexture。如果活动 RenderTexture 为 null，则所有内容都渲染到主窗口。

设置 RenderTexture.active 等同于调用 Graphics.SetRenderTarget。通常，在实现自定义图形效果时，您会更改或查询活动渲染纹理；如果您只需要让摄像机渲染到纹理，则使用 Camera.targetTexture。

当 RenderTexture 变得活跃时，如果它尚未创建，则会自动创建其硬件渲染上下文。

其他资源：Graphics.SetRenderTarget、GraphicsTexture.active。

using UnityEngine;
using System.Collections;

// Get the contents of a RenderTexture into a Texture2D
public class ExampleClass : MonoBehaviour
{
    static public Texture2D GetRTPixels(RenderTexture rt)
    {
        // Remember currently active render texture
        RenderTexture currentActiveRT = RenderTexture.active;

        // Set the supplied RenderTexture as the active one
        RenderTexture.active = rt;

        // Create a new Texture2D and read the RenderTexture image into it
        Texture2D tex = new Texture2D(rt.width, rt.height);
        tex.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
        tex.Apply();

        // Restore previously active render texture
        RenderTexture.active = currentActiveRT;
        return tex;
    }
}