This demo demonstartes manual vertex management, simple physics and collision detection.
CONTROLS:
LMB / W: Fly forward
RMB / S: Fly back
A: Move left
D: Move right
Mouse move: Look around
The gravity for each dot is calculated using Newton's gravity formula. It's position is then collected to display a line trail. This demonstrates usage of manual mesh creation and management of its vertices.
Source code: https://github.com/charlieamer/threejs-gravity