| output | Reference to the NativeArray to write the data into. The NativeArray or underlying memory cannot be Disposed until the request is complete. |
| src | The Texture resource to read the data from. |
| mipIndex | The index of the mipmap to fetch. |
| dstFormat | The target TextureFormat of the data. Conversion happens automatically if this format is different from the format stored on the GPU. |
| x | The starting x-coordinate, in pixels, of the Texture data to fetch. |
| width | The width, in pixels, of the Texture data to fetch. |
| y | The starting y-coordinate, in pixels, of the Texture data to fetch. |
| height | The height, in pixels, of the Texture data to fetch. |
| z | The starting z-coordinate, in pixels, of the Texture3D to fetch. For TextureCube, Texture2DArray, and TextureCubeArray, this is the index of the start layer. |
| depth | The depth, in pixels of the Texture3D to fetch. For TextureCube, Texture2DArray, and TextureCubeArray, this is the number of layers to retrieve. |
| callback | An optional delegate System.Action to call after Unity completes the request. When Unity calls the delegate, it passes the completed request as a parameter to the System.Action. |
AsyncGPUReadbackRequest Returns an AsyncGPUReadbackRequest that you can use to determine when the data is available. Otherwise, returns a request with an error.
Retrieves data asynchronously from a GPU Texture resource.
If the return value is a request with an error, calling AsyncGPUReadbackRequest.hasError returns true.
对于纹理数据，将根据源纹理的尺寸检查范围。如果图形 QualitySettings 设置得足够低而足以生成缩小尺寸的纹理，则必须请求缩小的尺寸。使用 QualitySettings.masterTextureLimit 通过向右移位的方式调整宽度和高度（以及 x、y，如果需要的话）。
For texture data, use SystemInfo.IsFormatSupported with FormatUsage.ReadPixels to query if the format is supported.
| output | Reference to the NativeArray to write the data into. The NativeArray or underlying memory cannot be Disposed until the request is complete. |
| src | The GraphicsBuffer to read the data from. |
| size | The size, in bytes, of the data to retrieve from the GraphicsBuffer. |
| offset | Offset in bytes in the GraphicsBuffer. |
| callback | An optional delegate System.Action to call after Unity completes the request. When Unity calls the delegate, it passes the completed request as a parameter to the System.Action. |
AsyncGPUReadbackRequest Returns an AsyncGPUReadbackRequest that you can use to determine when the data is available. Otherwise, returns a request with an error.
Retrieves data asynchronously from a GPU Graphics Buffer resource.
If the return value is a request with an error, calling AsyncGPUReadbackRequest.hasError returns true.
对于纹理数据，将根据源纹理的尺寸检查范围。如果图形 QualitySettings 设置得足够低而足以生成缩小尺寸的纹理，则必须请求缩小的尺寸。使用 QualitySettings.masterTextureLimit 通过向右移位的方式调整宽度和高度（以及 x、y，如果需要的话）。
For texture data, use SystemInfo.IsFormatSupported with FormatUsage.ReadPixels to query if the format is supported.