id

public int id { readonly get; set; }

You can use a non-zero value for id to uniquely identify the geometry used for ray tracing, no matter the location of the geometry data inside a vertex and index buffer. This can be used in scenarios where the geometry can be streamed in and out in different locations into a vertex and index buffer pool in GPU-driven rendering pipelines. If the value is 0 then Unity uses all the fields in RayTracingSubGeometryDesc to generate a geometry identifier.