# Minigolf

> A 3D browser replica of competition minigolf on the WMF concrete ("Beton") lane system - the
> system patented by Paul Bongni in 1950 - with all eighteen lanes in the standard's own fixed
> order, built at the standard's real dimensions, and with the source of every dimension shown
> lane by lane.

Runs entirely in the browser. No account, no model, no credits, no network calls.

## The system

- Concrete ("Beton") system, WMF Rulebook chapter 2.4 "System-specific rules concrete".
- Eighteen lanes, fixed in design AND in sequence: "the lanes must always be arranged in the same
  order, 1 to 18".
- Each lane 12.00 m long and 1.25 m wide, with a 2.50 m target circle and a 100 mm hole at its
  centre. Lane 7, the Weitschlag, is a long-drive fan about 25 m long.
- The tee marking is a 30 cm circle whose centre is 40 cm from the start of the lane, with an 8 cm
  centre mark.
- Mirror-image versions are permitted on lanes 4, 5, 9, 11, 12, 13, 14 and 16, and on no others.
- The lanes are officially NUMBERED, not named. The familiar names - Pyramiden, Salto, Rohr,
  Labyrinth, Vulkan, Winkel, Blitz - are the official names of the SEPARATE Miniaturgolf system's
  thirty-lane catalogue. Lane 7 "Weitschlag" is the one concrete lane with a name anyone uses.

## The rules implemented

- Every stroke counts one point. Not holed in six strokes: one further point, so seven, which is
  the highest possible score on a lane.
- The border line is passed when the ball's point of contact has passed it. If it has not been
  passed, the next stroke is from the tee.
- A ball that leaves the playing field after passing the border line is replaced where it left it.
- A ball at rest within 20 cm of a rail may be placed out to the repositioning line - on every
  system. 30 cm off an obstacle it has already passed, on concrete.
- A ball that rolls back over the border line towards the tee is stopped there.
- Holed when it has come to rest in the target so that it cannot leave under its own power.
- Lane 18 has no hole: it is completed when the ball climbs the slope and stays in the collecting
  box.

## The physics

- A struck ball starts sliding and reaches rolling at 5/7 of the speed it was struck, after
  12 v0^2 / (49 mu_k g).
- Rails scale the normal velocity by the ball's restitution - which is the square root of the
  sport's own bounce test, at most 85 cm from a 1 m drop - and take Coulomb friction off the
  tangential component, so a rebound is always shallower than a mirror.
- The hole is a real pit with a rim. Nothing in the engine knows a capture speed; a ball crossing
  too fast clips the far lip and rides out. The measured threshold agrees with the closed form
  V <= c*sqrt(2g/r) to within a few per cent, and that closed form reproduces the 1.626 m/s
  Holmes (Am. J. Phys. 59, 1991) reports for a 108 mm golf hole.

## Honest limits

- The obstacles' own dimensions are NOT published: chapter 2.4 defers to Paul Bongni's signed
  construction drawings, which are not public. Every obstacle size and position in this app is a
  reconstruction, and the app lists them per lane beside the sourced figures.
- The rail height and the hole depth are not stated in any rule document checked.
- No federation document publishes how fast a concrete lane runs, so the friction comes from
  measurements of a golf ball on a putting green.

## Files

- /               the game
- /CREDITS.txt    every source, and every reconstructed figure in full
- /LICENSE.txt    MIT for the code

Not affiliated with, endorsed by or connected to the World Minigolfsport Federation or any of its
member federations.