C/C++ library for point cloud & mesh manipulation ?

[Vin]

Hi,

I'm looking for open source or commercial C/C++ libraries with some or
all of the following point-cloud/mesh manipulation capabilities:

- resampling point clouds

- registering two point cloud images

- segmenting point clouds or meshes based on bounding coordinates

- creating triangular meshes from point clouds (possibly with varying
mesh densities)

Any suggestions are welcome.

Thanks !