More efficient physics

[Enigma503]

The units of physics in KSP are parts, i.e. they are considered to be rigid, indivisible bodies. The joints between them are flexible; they allow a craft to flex and break. This is a perfectly acceptable situation. However, as the number of parts increases, the calculations become unmanagable. The performance of Ubiozur's welding mod (http://kerbalspaceprogram.com/ubioweldingltd/), demonstrates that it is possible to simplify the calculations, while retaining gameplay (mostly). Is it not possible to dynamically 'weld' parts together or treat them as separate bodies, depending on the situation? Or even better, to treat the whole spacecraft as a single (wobbly) body, until a breakpoint becomes probable somewhere. It would be nice to be able to build mighty stuff in the mighty environment of KSP, with a less mighty PC. Of course, the introduction of larger parts in 0.23.5 will help with that, but large space stations or detailed motherships will remain a source of major lag. Any thoughts or news on this (old) issue?

[Kasuha]

The welding mod definitely helps with the physics simulation for large ships, but it's at a price of kind of cheating on physics of the ship. Welded parts are considered rigid bodies which affects how they transfer forces through the ship. Meaning a ship which would break under thrust will no longer break when its parts are welded, for instance.

Any optimizations to the physics simulation would be very welcome but I believe these need to come from the physics engine itself, not from KSP developers building on it.

Unity is, however, constantly in development and recently it is preparing upgrade of the PhysX simulator to newer version. If nothing else, this version is known for its substantially improved performance. So we may hope things will get better.

[vexx32]

This is less so more "efficient" physics as it is just taking shortcuts to make things easier, really. The welding mod can help, but it's really not a very elegant solution; it's primarily a brute-force solution.

[Nuke]

ultimately its a tradeoff between accurate physics and fast physics. the arm pack is supposed to bring in that new unity feature that lets us get away without so many struts. i figure half of my part counts are struts, and things that exist just so i have a place to attach a bunch of struts.