Limits

Limits

What it does not do, or does only roughly. Nothing here is hidden from the other pages.

Left to the game

• Water. A craft over water is never armed: what a splash does is worked out by the game from the same crash tolerance, and this mod leaves it alone. A wreck sliding off the land into the sea is handed back to the game at the shore, and the game's rules for splashing down apply from there.
• Kerbals on foot, flags, asteroids and comets are left as the game has them.
• A craft that is not moving fast near anything is the game's: only a craft that could hit something faster than its weakest part can take, within about two seconds, is watched.

Roughly

• The craft is pushed as one rigid body in a blow and in the slide. A real airframe bends and buckles; here what bends is the torn skin as it is drawn, and what the game's own joints let bend (they are softened as a part is hurt).
• A torn part is drawn, not rebuilt for the physics: its collider is the convex hull of what is left of its skin (so a torn tank lies and slides as a lump with its underside gone, not as the tube it was, and a hollow shell is solid to the ground), and its mass goes down with its skin; its strength in later blows is worked out from what was done to it before, not from its new shape.
• A torn tank's inside is its wall's (since 0.3.0): the ring frames and ribs are painted on the inside of the wall, with no depth of their own, and there are no domed bulkheads at a tank's ends or between its two propellants. Seen in the game on 2026-10-18: an FL-T400 blown open on the pad, looked at from 3 m in Photo Studio.
• Every part of a kind tears along the same lines: the panels are cut once for each kind of part, so two FL-T800s hurt the same way look alike (they are seldom hurt the same way).
• A torn part stops moving its own pieces: what the game moves inside a part (an engine's gimbal, a panel that unfolds) stays as it was when the part was first torn.
• Engines are not cut: an engine's bell, its pump and its mounting each come away whole (dented when crushed or ground). Dragged along the ground an engine is worn as a whole and loses them one after another (see How it works); it is never torn into panels as a tank is, and what is left of it at rest is whole meshes, a mounting ring with a pump on it, say.
• On paving an engine is held back harder than plain friction would hold it. Steel dragged over concrete is held back by half its weight or so, at most by about its whole weight where it gouges: a loose engine doing 65 m/s would go on for two to four hundred metres, and until 0.2.2 it did (240 to 330 m along the runway, most of it rolling and bounding, unmarked). What was asked for is a wreck that does not glide. So besides friction (seven to twelve tenths of its weight) the mod gives an engine what it calls catching, which grows with speed and is by far the greater part when it is fast (some 3 g in all at 67 m/s), and wears it to pieces by the work of both. That is a rule made by eye, not a measurement. "How far a wreck slides" divides all of it: at 3 an engine goes about as far as friction alone would let it.
• A wreck does not bound, and does not roll (since 0.2.2): what strikes is taken to give way, and a wreck that rolls is held back as one that slides. A real wreck does bounce a little, and a wheel torn off a real aeroplane rolls a long way; here a part that is round (a pod, an engine on its mounting ring) no longer does either once it is part of a wreck.
• Pieces collide as the convex hulls round them (a box round a small one): a curved panel lies on the ground as its hull does, not in its hollow, and pieces do not break further when they hit. Bits (shreds, rivets, foil, clods, slabs of turf) do not collide with anything but the ground beneath where they were thrown from, taken as flat.
• A part whose meshes cannot be read (some mods' parts are packed so), or that is hurt before its skin has been cut into panels (a craft that hits within a fraction of a second of coming within reach), breaks up the old way: whole, into a few pieces of its skin, when hurt past whole.
• The ground is not changed: the game rebuilds its terrain as the view moves, so a scar or a crater is a mesh laid on the ground. A mesh cannot be drawn below the ground's own surface, so a scar's floor is drawn at the ground's level, its depth only in its shading and its low lips, and a wreck sits down into the ground by as much as it has dug in. Seen from low down a scar reads as a torn brown band, not a trench. Far off, where the game draws the ground more coarsely, a mark may sink into it or stand a little proud of it.
• A scar is a picture laid on the ground, a few centimetres proud of it: a mesh a point every 0.4 m along and thirteen across, its lips no more than nine centimetres high, its edge cut out of the picture into clods and crumbs. (Until 0.2.2: a point every 0.8 m, lips up to 0.3 m, and from four metres they were broad smooth facets, "like folded sheeting".) Its floor has no depth of its own. The crumbs beyond its lips are flat, and at a distance they are too small for the picture's coarser copies and are not drawn. Where a wreck split, two scars cross at slightly different heights. A turn of the picture is as long as the scar is wide twice over: along a long straight scar the same lumps come round again.
• Friction and ploughing do not know the ground beyond paving and soil: grass, sand, rock and snow are all soil, and the Mun is soil too. At the space centre the grass along the runway (its shoulders and the lawn beyond) is told from the tarmac and is soil since 0.2.2; the grounds round its buildings are all still paving, grass or not (looked at by the hangar: what a craft touches there is a collider that is not drawn, and the mod cannot read what is drawn over it). Other launch sites: whatever the game tags as a runway or a pad is paving, the rest soil.
• No sound of its own: the explosions are the game's (or Volumetric Explosions'), and a slide is silent.

Kept short

• Pieces and bits are not kept: they go when the flight is left, saved or loaded, and pieces in high time warp and when they are more than 2.4 km from the craft being flown. The marks on the ground and the torn parts still there are kept in the save since 0.3.0 (see How it works); a torn part of a craft that is not near when the game saves keeps what the last save said of it. Tried through the development build's own keep and lay-again (2026-10-19); a quicksave and quickload with the released mod, not yet.
• At most so many pieces ("Pieces at most", 150 as installed): in a very big crash the oldest go early. At most 900 bits, 24 scars and 16 craters at once.
• The fire on a burning wreck is puffs of flame and smoke laid into the air where it burns, not one of the explosions mod's riding flames (those cost a patch of air each): up close its flame is a cloud of burning puffs rather than a steady flame. What switching them on costs was measured again on 2026-10-10, with Volumetric Explosions 0.6.0's new flames: the same crash, twice each way, ran at 28 and 33 frames a second in its first two seconds with them against 41 and 45 without, and at 29 to 39 against 42 to 66 in the eight seconds after. They stay off.
• Smoke from pieces is laid only where there is a patch of air already (an explosion's cloud, a wreck's trail): a piece flung far from any fire trails nothing (see How it works).

Other mods

• While a craft is armed, its parts' crash tolerance is a very large number. A mod that shows crash tolerance (Kerbal Engineer, say) shows that while it lasts; a mod that reads it to decide something (a mod of its own for crashes, or for buoyancy) gets that number too. Mods that change crash tolerances themselves will have their change kept and given back, as long as they do not change it while the craft is armed.
• A torn part's own renderers are hidden while this mod draws it, and its own colliders switched off while its box stands in for them: a mod that changes a part's look or colliders in flight will not see its change on a torn part.
• Mods that destroy parts their own way (BDArmory's weapons, say) are not affected: this mod only decides what blows from running into things do.

Cabins (since 0.5.0)

• A cabin's strength is a rule, not a measurement: no more than a capsule's crash tolerance (14 m/s, the Mk1 pod's) for any part with seats, whatever the game gives it, and its crew are killed once it is crushed in by a quarter of its length, has less than three fifths of its shell left, or its own propellant has gone up in it. A real crew's chances in a crash turn on far more (their seats, their straps, where the cabin gives way); here they live or die with their cabin as a whole.
• The crew die only as the game kills them: with their part. A cabin broken open goes to pieces, all of it; there is no cabin left lying torn open with its crew dead inside, nor kerbals thrown out of a wreck.
• See-through pieces are not torn: what a part draws with a see-through material (the Mk1 Cockpit's flag, glass on other mods' cockpits) is left drawn as it is while the part is torn, until the part goes (the stock pods and cockpits' windows are painted on their skin and are torn with it: looked at in the game, 2026-10-25).
• A part with seats is a cabin however little it is built for crew (the external command seat, a passenger cabin): it is given a capsule's strength at most, which leaves those whose tolerance is below it (the seat's 6 m/s) as they were.

Where it has been run

On a Mac (Apple M5 Pro, KSP 1.12.5 under Rosetta, OpenGL), and on Windows 11 (KSP 1.12.5, Direct3D 11) on 2026-10-10 (0.1, before 0.2.0's tearing and trails): Kerbal X crashed by the pad with Volumetric Explosions, its parts dented and broken by this mod (its lines in the game's log), the wreck sliding 26 m, the fire and smoke drawn as a volume; then (0.2.0) into the assembly building (see What was tested). It is plain C# with no shader of its own. It has not been run on Linux.