b3d-tank

A tracked vehicle: a tank, a bulldozer, a tracked loader. Each track runs at its own speed, so it steers by running one faster than the other and turns on the spot with the stick to one side. It climbs what a car would slide back down, and stops dead when you let go. The handling is ground-vehicle; the b3d-car page has one to drive beside the cars.

Demo

import { b3d, b3dTank, inputFocus, playground } from 'tosijs-3d'

const tank = b3dTank({ x: -4, z: 10, player: true })
preview.append(
  b3d(
    { style: 'width: 100%; height: 100%', gamepad: 'left_stick,right_stick,left_trigger,right_trigger,right_bumper' },
    ...playground({ targets: 0 }),
    inputFocus(tank)
  )
)

.preview { height: 100%; }

W and S (on a gamepad the right trigger, and the left trigger or right bumper) drive forward and back, A and D (the left stick) steer; with nothing else held they pivot it where it stands. The arrow keys (the right stick) aim the turret: left and right traverse it, and pulling back raises the gun (pushing forward lowers it). Clicking the right stick swaps up and down to the camera, which then moves along its arc as a car's does (in a headset, in and out), and back. The camera follows the turret, leading it a little while it turns, and the turret holds its aim while the hull turns under it.

Its body

Given no url or library, it builds a plain one: a hull, a turret, and two tracks whose treads move with the belts. A model of your own needs its tracks as meshes with track in their names, one each side; the tank stands them on five points along their undersides, and its raised ends climb: it gets up a step about as high as its tracks. A node named turret turns on the hull, and one inside it named mantlet (or else gun, barrel or cannon) elevates (from -8° to 20°); put each one's origin on its pivot. Meshes named wheel turn with their side's track.

Tracks can be LINKS instead (meshes named track_link…), carried round by the model's own animation, one cycle moving each link onto the next one's place: the tank plays it by the distance the track has run over the ground, so the links grip at the pace of the ground, either way and turning on the spot. Its other track meshes (a solid belt drawn over the links) are then hidden; guards stay. Cross Country drives Tonio's tank, built this way.

Attributes

Those of b3d-car (url, library, meshName, scale, enterable, mass, maxSpeed, acceleration, braking, grip, headlights, sound), with a tank's defaults: 20 t, 12 m/s, 3 m/s². And: