fast-voxel-raycast

fast-voxel-raycast

Fast raycasting through voxels.

This is a fork of voxel-raycast,
using the faster, simpler algorithm described in
this paper
by Amanatides and Woo.

In general it functions equivalently to the parent library, except for
edge cases (e.g. when the raycast precisely touches the corner of a solid voxel),
in which case no particular behavior is defined.

$3

npm install fast-voxel-raycast

$3

``js
var raycast = require('fast-voxel-raycast')

raycast( getVoxel, start, direction, distance, hit_position, hit_normal )
`

* getVoxel - a function(x,y,z) that returns a truthy value for whether each voxel should block the raycast
* start - origin of the ray
* direction - direction of the ray
* distance - how far to check the ray before giving up
* hit_position - result array, gets populated with the point of impact
* hit_normal - gets populated with a normal vector pointing away from the voxel that was struck

Returns: whatever value was returned by the getVoxel function for the struck voxel,
or 0 if no voxel was struck.

$3

`js
var raycast = require('fast-voxel-raycast')

var getVoxel = function(x,y,z) {
// return a truthy value here for voxels that block the raycast
return (y<0) ? 1 : 0
}

var hit_position = []
var hit_normal = []

var result = raycast( getVoxel, [3,4,5], [1,-1,-1], 20, hit_position, hit_normal )

if (result != 0) {
console.log('hit:', result, hit_position, hit_normal)
} else {
console.log('no truthy voxel was struck')
}
``