I have added the CollisionSystem code to Lyridia and things are looking mostly ok.  I can create a BoxGeometry, translate it, rotate it, and add it to the collisionTargets array and the collision detection system works great.  There’s still no gravity and the collision sphere is too big, but it works.  I’m a little disappointed because I tried switching out the BoxGeometry with a SphereGeometry and the results were a little mixed.  The system seemed to mostly work but I was able to walk into the sphere in one place at least one time, and another time it actually crashed the browser.  So there is still some work to do on the collision system, but overall I’m still very pleased with it.  The next step is to add an invisible collision mesh to another object in the world, like the fence or the Penrith farmhouse, and make sure I can use the system there.