PointCloudLibrary/pcl ? reverse-engineered prompt

Build me a C++ library for working with 2D and 3D point clouds, something I can use for robotics or computer vision projects.

I want the core pieces to cover loading and saving common point cloud formats, filtering noisy data, finding features, segmenting objects, matching and registering clouds, basic geometry tools, and simple visualization so I can inspect results. It should also include a few small example programs and tests so I can see how the pieces fit together.

Make it clean to build on Linux, Windows, and Mac, with straightforward documentation and a couple of tutorials that show common tasks like reading a cloud, cleaning it up, and aligning two scans. If you need to look up current docs or best practices online, go ahead.