IntPtr Pointer to an underlying graphics API Texture resource.
Retrieve a native (underlying graphics API) pointer to the Texture resource.
Use this function to retrieve a pointer/handle corresponding to a particular Texture
as it is represented on the native graphics API level.
This can be used to enable Texture manipulation from native code plugins.
注意：使用 Unity API 修改纹理对象的像素数据时，会更改基础图形 API 原生指针。调用 GetNativeTexturePtr 可获取新的原生指针。
For specific platforms, Unity has the following specifications:
On Direct3D-like devices, Unity returns a pointer to the base Texture type (ID3D11Resource on D3D11, ID3D12Resource on D3D12).
On OpenGL-like devices, the GL Texture "name" is returned; cast the pointer to an integer type to get it.
On Metal, Unity returns an id<MTLTexture> pointer.
On Vulkan, Unity returns an VkImage pointer.
On platforms that do not support native code plug-ins, this function always returns NULL.
Note that calling this function when using multi-threaded rendering will synchronize with the rendering
thread (a slow operation), so best practice is to set up needed Texture pointers only at initialization
time.
另请参阅：原生代码插件、Texture2D.CreateExternalTexture、Cubemap.CreateExternalTexture、RenderTexture.GetNativeDepthBufferPtr。