將 RenderTexture 轉換為 Texture2D

Question

我需要將一個 RenderTexture 對象保存到一個 .png 文件中，然后該文件將用作環繞 3D 對象的紋理。 我的問題是現在我無法使用 EncodeToPNG() 保存 RenderTexture 對象，因為 RenderTexture 不包含該方法。 如何將 RenderTexture 對象轉換為 Texture2D 對象？ 謝謝！

// Saves texture as PNG file.
using UnityEngine;
using System.Collections;
using System.IO;

public class SaveTexture : MonoBehaviour {

    public RenderTexture tex;

    // Save Texture as PNG
    void SaveTexturePNG()
    {
        // Encode texture into PNG
        byte[] bytes = tex.EncodeToPNG();
        Object.Destroy(tex);

        // For testing purposes, also write to a file in the project folder
        File.WriteAllBytes(Application.dataPath + "/../SavedScreen.png", bytes);
    }
}

Answer 1

創建新Texture2D ，使用RenderTexture.ReadPixels讀取來自像素RenderTexture到新Texture2D 。 最后，調用Texture2D.Apply(); 應用更改后的像素。

Texture2D toTexture2D(RenderTexture rTex)
{
    Texture2D tex = new Texture2D(512, 512, TextureFormat.RGB24, false);
    // ReadPixels looks at the active RenderTexture.
    RenderTexture.active = rTex;
    tex.ReadPixels(new Rect(0, 0, rTex.width, rTex.height), 0, 0);
    tex.Apply();
    return tex;
}

用法：

public RenderTexture tex;
Texture2D myTexture = toTexture2D(tex);

---

您可以將其設為擴展方法（恢復之前的活動 RenderTexture 以避免出現意外）：

public static class ExtensionMethod
{
    public static Texture2D toTexture2D(this RenderTexture rTex)
    {
        Texture2D tex = new Texture2D(rTex.width, rTex.height, TextureFormat.RGB24, false);
        var old_rt = RenderTexture.active;
        RenderTexture.active = rTex;

        tex.ReadPixels(new Rect(0, 0, rTex.width, rTex.height), 0, 0);
        tex.Apply();

        RenderTexture.active = old_rt;
        return tex;
    }
}

用法：

public RenderTexture tex;
Texture2D myTexture = tex.toTexture2D();