# Arc Between Vectors

Table of contents

# Draw an Arc Between Two Vectors

Given an origin O and two vectors OA and OB this snippet draws an arc between the two vectors with a given radius. The arc can be drawn in three types 0 (default) a solid line, 1 a dashed line, 2 filled between arc and vectors.

``````function showAngleSector(origin, vector1, vector2, radius, sectorType) {
radius = radius || 1;
sectorType = sectorType || 0;
var cross = BABYLON.Vector3.Cross(vector1, vector2);
var dot = BABYLON.Vector3.Dot(vector1, vector2);
var angle = Math.acos(dot / (vector1.length() * vector2.length()));
var points = [];
var minNb = 4;
var factor = 2;
var nbPoints = Math.floor(radius * angle * factor);
nbPoints = (nbPoints < minNb) ? minNb : nbPoints;

var firstPoint = ((BABYLON.Vector3.Normalize(vector1)).scale(radius));
var lastPoint = ((BABYLON.Vector3.Normalize(vector2)).scale(radius));
var matrix;
var ang = angle / nbPoints;
var rotated;
for (var i = 0; i < nbPoints; i++) {
matrix = BABYLON.Matrix.RotationAxis(cross, ang * i);
rotated = BABYLON.Vector3.TransformCoordinates(firstPoint, matrix);
points.push(rotated.add(origin));
}
points.push(lastPoint.add(origin));

var sector;
switch (sectorType) {
case 0:
sector = BABYLON.Mesh.CreateLines("sector", points, scene);
break;
case 1:
sector = BABYLON.Mesh.CreateDashedLines("sector", points, 3, 1, nbPoints , scene);
break;
case 2:
var pointO = [];
for (var j = 0; j < points.length; j++) {
pointO.push(origin);
}
sector = BABYLON.Mesh.CreateRibbon("sector", [points, pointO], null, null, 0, scene);
break;
default:
sector = BABYLON.Mesh.CreateLines("sector", points, scene);
break;
}
return sector;
}
``````