View source for SICK Laser Scanner

[[Category: JavaScript]]
[[Category: Simulation]]
Author: (Jeff Craighead)

Thanks to StarManta for help with the Quaternion math.

==Description==
This script simulates the SICK LMS laser scanner by doing a bunch of raycasts around a single point.  There are two functions each behaves slightly differently.  See the comments in the code. 

==Usage==
Attach this to an empty object, which becomes the scanner. You'll need some sort of query function to retrieve the range data for use in other parts of the game/simulation.

==JavaScript==

<syntaxhighlight lang="javascript">
var arcAngle = 180.0;
var numLines = 181;
var maxDist = 8.0;
var scansPerSec = 3;
private var ranges : float[];
private var timer = 0.0;

function LateUpdate(){
	DoScan2();
}

//Centers scan of arcAngle degrees with numLines rays around "forward". Centering accounts for the "missing" last ray by arcAngle/(2*numLines) degrees.
//Start and end lines are not exactly on 0 and n degrees but offset by arcAngle/(2*numLines) degrees.
function DoScan1(){
	if(timer>1.0/scansPerSec){
		ranges = new float[numLines];
		for (l=0;l<numLines;l++) {
			var shootVec : Vector3 = transform.rotation * Quaternion.AngleAxis(-1*arcAngle/2+(l*arcAngle/numLines)+arcAngle/(2*numLines), Vector3.up) * Vector3.forward;
			var hit : RaycastHit;
				Debug.DrawRay(transform.position,shootVec,Color.red);
			if (Physics.Raycast(transform.position, shootVec, hit, maxDist)) {
				Debug.DrawLine(transform.position, hit.point, Color.red);
				ranges[l]=hit.distance;
			}
			else ranges[l]=maxDist;
		}
		timer=0;
	}
	else timer+=Time.deltaTime;
}

//Centers scan of arcAngle degrees with numLines rays around "forward". Centering accounts for the "missing" last ray by adding the last "extra" ray.
//Start and end lines are exactly on 0 and n degrees but there are numLines+1 rays.
function DoScan2(){
	nLines=numLines+1;
	if(timer>1.0/scansPerSec){
		ranges = new float[nLines];
		for (l=0;l<nLines;l++) {
			var shootVec : Vector3 = transform.rotation * Quaternion.AngleAxis(-1*arcAngle/2+(l*arcAngle/numLines), Vector3.up) * Vector3.forward;
			var hit : RaycastHit;
				Debug.DrawRay(transform.position,shootVec,Color.blue);
			if (Physics.Raycast(transform.position, shootVec, hit, maxDist)) {
				Debug.DrawLine(transform.position, hit.point, Color.blue);
				ranges[l]=hit.distance;
			}
			else ranges[l]=maxDist;
		}
		timer=0;
	}
	else timer+=Time.deltaTime;
}
</syntaxhighlight>