Yes, you can do those in fabricjs. Since fabricjs is a vector based system, its cpu intensive computations slow down operations. The best is to work on bitmaps directly. That way it will be faster. Maybe owayo is working directly on texture (using bitmaps) instead of vector based system like fabricjs.
Or you can mix both, use bitmaps where it is possible, and from time to time map these bitmaps to corresponding vector ones. But if you don’t have much time, fabric.js would be a nice start for this.