Physics All the Things!

[almagnus1]

Soo... how difficult would it be to force physics to calculate all the things all the time?

What would be the proper approach to do this via code?

[FancyMouse]

Add up all the part counts of your current vessels on mission, and then try to build a ship with that part count and see how it launches?

[almagnus1]

Add up all the part counts of your current vessels on mission, and then try to build a ship with that part count and see how it launches?

But what about other ships in other orbits that would normally go into the planet's atmosphere?

As I understand the way the game engine works, it only applies physics to the currently active ship, and only if it's not currently under time warp.

So how difficult would it be to get physics to work on all the things (probes, other ships, etc) when it makes sense?

[Captain Sierra]

But what about other ships in other orbits that would normally go into the planet's atmosphere?

As I understand the way the game engine works, it only applies physics to the currently active ship, and only if it's not currently under time warp.

So how difficult would it be to get physics to work on all the things (probes, other ships, etc) when it makes sense?

It partly depends on what kind of physics you want to force-load. KSP calculates most physics on a per-part basis. There are a few exceptions to this (and more that are activated above a certain time warp value), with orbital pathing being one. Atmospheric drag, however, is not, to force-load that so craft which dip into the upper atmosphere experience orbital decay would apply the full physics impact of undergoing reentry with that vessel, plus whatever vessel you're currently flying.

Now, your request of "force physics to calculate all the things all the time" would induce so much computational load, the game would grind to an unplayable halt. Unity 5 will allow for multithreading of physics in multi-craft situations (which means bases and other constructions are only limited by the largest single-vessel by part count instead of the total part count within physics range), but there's still limits and what you're considering is breaking those limits.

TL;DR: the game doesnt calculate physics all the time for a reason.

If you still want to know more, there's a few mods out there which force vessels to stay loaded (via a part hook). I suggest you take a peek at their source if thats your fancy.

[sarbian]

The CPU usage is not even the real problem. Physic is done in single precision and anything beyond a certain range will loose a lot of precision

(This is the part where I am rusty but It should be OK)

If you want a precision of +/-0.005 meter (which is already not fantastic) with a float you want your numbers to be between -16384 and 16384. So beyond 16km your physic precision is getting worse and worse.

If your active a vessel physic near the mun when you are on kerbin that vessel physic would have a precision of +/- 2 meters.

[almagnus1]

Ok, so what are the exact implications of setting the physic range to MAX_DOUBLE?

@Captain Sierra:

Random question, but did you ever play any of the Outposts or Space Quests?