Depending on the original data, you may find raycasting to produce faster results. You will need a hierarchy or a quick look up method, otherwise it will be really slow. For instance, a point cloud with a octree hierarchy could be faster than mesa and rasterization if the point cloud is too massive.
Still though, you may need to research to assess correctly. Sometimes a few tweaks in rendering can make everything really fast. For instance, VTK has a lot of of linear processing in the actors. So if you amount of actors is high (thousands) some updates may be slower per frame if you instead join all the data in a single actor. Or at least, that was my experience in the past.