Getting a non-interleaved native vertex buffer

Hi! I'm currently trying to pass a GL vbo from Unity into nvidia's OptiX raytracer without copying data. I'm currently running into a problem where OptiX accelerators expect the vertex buffers to arrive as packed float3 structures, but unity provides native vertex buffers with all the vertex attributes interleaved. is there some way to get a non-interleaved native vertex buffer from Unity? Thanks!