Algodoo

UDG -- In a comment to me, you asked: "is there a function that can determine the distance at which a laser changes direction, such as a reflection or refraction, instead of the position of the object that reflected or refracted the laser?" Well, this scene doesn't do that. Because you set it up with only one laser beam (maxRays = 1), the laser cannot reflect off of one box and hit another box. A few parameters need to be changed to make that happen. Here is how you can do that.... In the laser, change maxRays to 2 or more. Then in the first box that the laser hits, change the "Refractive Index" to some high value (infinite has the highest reflection). After doing these things, you will then be able to bounce the laser beam off the first box, and into the second box, and the readout will show the distance to the second box!

I meant to find the point where the laser collides, not neccesarily bends. I'm great with simulated mechanics and math, but not with words, unless I think hard on what I want to say. I simply wanted to make an altimeter. (I hope that's its name!)

No problem. So, according to your recent description of what you wanted to do, it does look like you made that happen in this scene. But it is not called an "altimeter" because an altimeter is a device that measures height above the ground. For example, and airplane measures its altitude with an altimeter. What you have here in this scene is simply a distance measuring device.