Drawing Lights is a 3D drawing tool built in Unity WebGL. 

Here's the online link of Drawing Lights:  https://drawing-lights.herokuapp.com/

The online version needs 2 minutes to be loaded.

Here is the source for it - https://github.com/yining1023/drawing-lights.

People can move the cursor to move the camera, click mouse to draw a colorful light in a random Z position. Also people can click Arrow Key to move camera( Up and Down for Z axis, Left and Right for X and Y axis ), "C" to collapse, and "X" to delete all. Every sphere is a white sphere with different color light. There are stretched cubes connecting every two spheres. The cubes are lights themselves, and they can also reflect the different color light from spheres.