using UnityEngine;

public class SaveRenderTexture : MonoBehaviour {
    public RenderTexture texture;

    [ContextMenu("Save")]
    private void Save() {
        var currentActiveRT = RenderTexture.active;
        RenderTexture.active = texture;

        var screen = new Texture2D(this.texture.width, this.texture.height, TextureFormat.ARGB32, false);

        screen.ReadPixels(new Rect(0, 0, this.texture.width, this.texture.height), 0, 0);
        var bytes = screen.EncodeToPNG();

        System.IO.File.WriteAllBytes(Application.dataPath + "/Temp/screen.png", bytes);

        RenderTexture.active = currentActiveRT;
    }
}