Using a provided 3D rendering, embed the rendering into a webpage.
The 3D graphics engine used should be WebGL and Open Source, not requiring any additional licensing.
The engine should load quickly, allowing the user to navigate left and right, up and down and zoom in and out based on the camera location.
The user must be able to pick a point (node) in the map which will then be saved. That same point must be easily accessed with one click for future.
A few engines to consider might be Irrlicht Engine, Minko or OGRE.