I was inspired by a video by Master of Shapes, where they converted a vive tracker into a virtual spray can that can digitally paint any surface. At the time, I was developing Paint-AR an augmented reality painting tool, and had many custom brushes already developed. Getting this to work in VR and simultaneously projected on a wall meant that I needed to match up 2 different coordinate systems, the world coordinates of the VR space, and the 2D Projector space. I also wanted to be able to align this on any wall with minimal setup. I developed a method that aligns the physical wall with the virtual wall, and adjusts the screen coordinates of the projector to get everything to line up perfectly. You can see some of the results below.