I have a physically-simulated object with gravity disabled being propelled very quickly along the X axis. When the object’s X-coordinate hits roughly 262,000, it disappears completely. This doesn’t happen if the object does not have physics enabled.
Is there a way around this, or have I hit a limitation of the physics engine?
First answer: There’s no way to prevent an object at X > 262144 from being destroyed completely. It’s a limitation of the physics engine - the world maximum size is a cube 524288 units on each axis, centered at the origin.
Second answer: However, what might work is to prevent the object from reaching 262144. There’s a function (whose name I cannot find right now) for recentering the entire world at a given coordinate. Obviously if you’re trying to simulate a space larger than 524288 units, this won’t be of use, but if the important parts of the world are relatively near each other, just moving the entire world around it might work.
Finally, if you’re trying to make Kerbal Space Program, you’ll have to do some more elegant things with implicit frames of reference. Floating-point values lose accuracy quickly as you travel away from the origin, so you’ll have to do some nasty numeric dances in order to deal with that.