[Unity] Save RenderTexture to image file

SaveRenderTextureToFile.cs

using UnityEngine;
using UnityEditor;

public class SaveRenderTextureToFile {
    [MenuItem("Assets/Save RenderTexture to file")]
    public static void SaveRTToFile()
    {
        RenderTexture rt = Selection.activeObject as RenderTexture;

        RenderTexture.active = rt;
        Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false);
        tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
        RenderTexture.active = null;

        byte[] bytes;
        bytes = tex.EncodeToPNG();
        
        string path = AssetDatabase.GetAssetPath(rt) + ".png";
        System.IO.File.WriteAllBytes(path, bytes);
        AssetDatabase.ImportAsset(path);
        Debug.Log("Saved to " + path);
    }

    [MenuItem("Assets/Save RenderTexture to file", true)]
    public static bool SaveRTToFileValidation()
    {
        return Selection.activeObject is RenderTexture;
    }
}

SaveScreenshotToFile.cs

using UnityEngine;
using UnityEditor;

public class SaveScreenshotToFile {
    [MenuItem("Custom/Render Camera to file")]
    public static void RenderCameraToFile()
    {
        Camera camera = Selection.activeGameObject.GetComponent<Camera>();
        
        RenderTexture rt = new RenderTexture(2560, 1440, 24, RenderTextureFormat.ARGB32, RenderTextureReadWrite.sRGB);
        RenderTexture oldRT = camera.targetTexture;
        camera.targetTexture = rt;
        camera.Render();
        camera.targetTexture = oldRT;
        
        RenderTexture.active = rt;
        Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false);
        tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
        RenderTexture.active = null;
        
        byte[] bytes = tex.EncodeToPNG();
        string path = "Assets/screenshot.png";
        System.IO.File.WriteAllBytes(path, bytes);
        AssetDatabase.ImportAsset(path);
        Debug.Log("Saved to " + path);
    }
    
    [MenuItem("Custom/Render Camera to file", true)]
    public static bool RenderCameraToFileValidation()
    {
        return Selection.activeGameObject != null && Selection.activeGameObject.GetComponent<Camera>() != null;
    }
}

Works like a charm. Thanks a lot!

Thanks. It helps me a lot.

Thank you!!

Thank you!! Here's a remix that takes a shot directly from the camera

static void SaveRenderTexture(RenderTexture rt, string path)
{
	RenderTexture.active = rt;
	Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false);
	tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
	RenderTexture.active = null;
	var bytes = tex.EncodeToPNG();
	System.IO.File.WriteAllBytes(path, bytes);
	AssetDatabase.ImportAsset(path);
	Debug.Log($"Saved texture: {rt.width}x{rt.height} - " + path);
}
[MenuItem("Assets/Take Screenshot", true)]
public static bool TakeScreenshotValidation() =>
	Selection.activeGameObject && Selection.activeGameObject.GetComponent<Camera>();
[MenuItem("Assets/Take Screenshot")]
public static void TakeScreenshot()
{
	var camera = Selection.activeGameObject.GetComponent<Camera>();
	var prev = camera.targetTexture;
	var rt = new RenderTexture(Screen.width, Screen.height, 16);
	camera.targetTexture = rt;
	camera.Render();
	SaveRenderTexture(rt, "Assets/screenshot.png");
	camera.targetTexture = prev;
	Object.DestroyImmediate(rt);
}

Since this gist seems useful to so many people, I added a variant which generates a screenshot from a camera, and works correctly with linear color space. This became necessary when we switched to using linear color space, since there was no way to create an sRGB render texture through the UI, and colors were coming out all weird in the screenshot otherwise (because most normal image files are expected to be in sRGB, not linear).

Also, in case you were wondering, simply changing Texture2D constructor parameter linear to true does not work, because ReadPixels does not perform the linear to sRGB conversion in this case, only actually rendering with a shader does.

Thanks @mrchantey for reminding me I have this ;)

Thank you for publishing this. Very helpful!

Remember to call Object.Destroy(tex) after you are done with the texture or it'll leak. See this example from unity docs

This is very helpful, thanks. But is there a way to retain the alpha information that the RT has?
EDIT: Turns out it was a simple as changing the texture format to TextureFormat.RGBA32

Thanks, helped a lot!

Would like to suggest making this gist a general png saver

https://gist.github.com/Thaina/44730376d4ef58bb52496d851634a531

if your having issues with SRGB to Linear color space( image is very dark compared), i found this change works

using UnityEngine;
using UnityEditor;

public class SaveRenderTextureToFile
{
[MenuItem("Assets/Save RenderTexture to file")]
public static void SaveRTToFile()
{
RenderTexture rt = Selection.activeObject as RenderTexture;
RenderTexture rtNew = new RenderTexture(rt.width, rt.height, 8, RenderTextureFormat.ARGB32);
Graphics.Blit(rt, rtNew);

    RenderTexture.active = rtNew;
    Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGBA32, false);
    tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
    RenderTexture.active = null;

    byte[] bytes;
    bytes = tex.EncodeToPNG();

    string path = AssetDatabase.GetAssetPath(rt) + ".png";
    System.IO.File.WriteAllBytes(path, bytes);
    AssetDatabase.ImportAsset(path);
    Debug.Log("Saved to " + path);
}

[MenuItem("Assets/Save RenderTexture to file", true)]
public static bool SaveRTToFileValidation()
{
    return Selection.activeObject is RenderTexture;
}

}

To add an alpha support just change Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false); to Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGBA32, false);