Real Time Physics Simulator (RTPS) was a semester long project that I worked on for one of my physics classes at Red Rocks Community College.

My original goal was to write a physics engine and leave it at that. Then I started talking with one of the other groups, and their project was to model tuned mass dampeners in buildings with K'NEX. Something went off in my brain and instantly I knew that these two projects were somehow complimentary to eachother. The focus then changed slightly and I decided to try and match the movements of their K'NEX skyscraper with my simulator. Although the simulations looked good, they were extremely diffucult to tune to the physical model. It was almost impossible to get the simulation to line up with the model for any significant duration of time, but the proof of concept was there.

Something that came up during development was the question of whether or not this program was actually a "real time" simulator, and to this day there are two conflicting opinions. I had the idea that because the simulator adjusts each new time step for the amout of time that the last step took, one second in the program would be one second of real time. The other opinion, was that of my uncle Chris Roeder, who has an MS in Computer Science and works for IBM. His srgument was that nothing in Java can ever be real time because of garbage collection. Once it starts, your program has to wait, and there really is no controlling when it starts because it has a mind of its own. Its too bad because I feel the name is so catchy.

One of the failures of this project was its ability to conserve energy. Somewhere there was a roundoff error or something similar (collision detection maybe?) that constantly adds energy to the system, making it unstable over long periods of time. Unfortunately I'm not entirely sure how to fix this problem.

In retrospect, another failure of this project was proper documentation. When I was writing code for this project, I didn't really think about using javadoc to my advantage, and now that I haven't touched the code in about a year re-learning all of the intricacies of it takes more time than necessary. One of my plans is to someday extend this to three dimensions after I've learned OpenGL, and re-write it in C++, and make RTPS into a true real time simulator.