Functionality to take Screenshots.
| CaptureScreenshot | PNG ファイルとして filename のパスでスクリーンショットを撮ります。 | 
| CaptureScreenshotAsTexture | Captures a screenshot of the game view into a Texture2D object. | 
| CaptureScreenshotIntoRenderTexture | Captures a screenshot of the game view into a RenderTexture object. |