RVIZ rendering of overlapping objects

edit

RVIZ uses the Ogre rendering engine to display the 3D scene. It uses Z-buffering to correctly draw occluded objects, so every object is drawn whether it eventually ends up on the screen or not, so having two identical point clouds for example will take twice as longer to render since each point (a square billboard by default) is being rendered twice.

I've not seen any options to down sample point clouds in RVIZ during UI interactions as some viewers do. If you're working with really large point clouds and it's getting un-manageable then you could down sample them yourself and broadcast both the full and reduced clouds. This is a bit of a cludge but you could switch between them in RVIZ if the interface starts running too slow to use.