As described on the polygon point generator page, the following script generates a point within a polygon by using an encompassing minimal circle to generate the points and then applying a select-reject algorithm to those generated points.
/////////////////////////////////////////////////////////////////////////// // Copyright (C) 2013 Wizardry and Steamworks - License: GNU GPLv3 // /////////////////////////////////////////////////////////////////////////// list wasDualQuicksort(list a, list b) { if(llGetListLength(a) <= 1) return a+b; float pivot_a = llList2Float(a, 0); a = llDeleteSubList(a, 0, 0); vector pivot_b = llList2Vector(b, 0); b = llDeleteSubList(b, 0, 0); list less = []; list less_b = []; list more = []; list more_b = []; do { if(llList2Float(a, 0) > pivot_a) { less += llList2List(a, 0, 0); less_b += llList2List(b, 0, 0); jump continue; } more += llList2List(a, 0, 0); more_b += llList2List(b, 0, 0); @continue; a = llDeleteSubList(a, 0, 0); b = llDeleteSubList(b, 0, 0); } while(llGetListLength(a)); return wasDualQuicksort(less, less_b) + [ pivot_a ] + [ pivot_b ] + wasDualQuicksort(more, more_b); } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2014 Wizardry and Steamworks - License: GNU GPLv3 // /////////////////////////////////////////////////////////////////////////// // determines whether the segment AB intersects the segment CD integer wasSegmentIntersect(vector A, vector B, vector C, vector D) { vector s1 = <B.x - A.x, B.y - A.y, B.z - A.z>; vector s2 = <D.x - C.x, D.y - C.y, D.y - C.z>; float d = (s1.x * s2.y -s2.x * s1.y); if(d == 0) return FALSE; float s = (s1.x * (A.y - C.y) - s1.y * (A.x - C.x)) / d; float t = (s2.x * (A.y - C.y) - s2.y * (A.x - C.x)) / d; // intersection at <A.x + (t * s1.x), A.y + (t * s1.y), A.z + (t * s1.z)>; return (integer)(s >= 0 && s <= 1 && t >= 0 && t <= 1 && A.z + t*(B.z - A.z) == C.z + s*(D.z - C.z)); } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2013 Wizardry and Steamworks - License: GNU GPLv3 // // www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html // /////////////////////////////////////////////////////////////////////////// integer wasPointInPolygon(vector p, list polygon) { integer inside = FALSE; integer i = 0; integer nvert = llGetListLength(polygon); integer j = nvert-1; do { vector pi = llList2Vector(polygon, i); vector pj = llList2Vector(polygon, j); if ((pi.y > p.y) != (pj.y > p.y)) if(p.x < (pj.x - pi.x) * (p.y - pi.y) / (pj.y - pi.y) + pi.x) inside = !inside; j = i++; } while(i<nvert); return inside; } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2013 Wizardry and Steamworks - License: GNU GPLv3 // // www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html // /////////////////////////////////////////////////////////////////////////// list wasPointToPolygon(list polygon, vector point) { integer i = llGetListLength(polygon)-1; list l = []; do { l = llListInsertList(l, (list)llVecDist(point, llList2Vector(polygon, i)), 0); } while(--i>-1); l = wasDualQuicksort(l, polygon); return [llList2Float(l, 0), llList2Vector(l, 1)]; } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2013 Wizardry and Steamworks - License: GNU GPLv3 // // www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html // /////////////////////////////////////////////////////////////////////////// vector wasPolygonCentroid(list polygon, vector start, float tollerance, integer power) { // calculate the distance to the point farthest away from the start. list wpf = wasPointToPolygon(polygon, start); float dist = llList2Float(wpf, 0); vector next = llList2Vector(wpf, 1); // now calculate the next jump point next = start + ((dist/power)/dist) * (next-start); // if it falls withing the tollerance range, return it; if(llVecMag(start-next) < tollerance) return next; return wasPolygonCentroid(polygon, next, tollerance, power*power); } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2011 Wizardry and Steamworks - License: GNU GPLv3 // /////////////////////////////////////////////////////////////////////////// vector wasCirclePoint(float radius) { float x = llPow(-1, 1 + (integer) llFrand(2)) * llFrand(radius*2); float y = llPow(-1, 1 + (integer) llFrand(2)) * llFrand(radius*2); if(llPow(x,2) + llPow(y,2) <= llPow(radius,2)) return <x, y, 0>; return wasCirclePoint(radius); } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2011 Wizardry and Steamworks - License: GNU GPLv3 // /////////////////////////////////////////////////////////////////////////// vector wasPolygonPoint(list polygon) { vector c = wasPolygonCentroid(polygon, llList2Vector(polygon, 0), 0.05, 2); float r = llList2Float(wasPointToPolygon(polygon, c), 0); vector d; do { d = c + wasCirclePoint(r); } while(wasPointInPolygon(d, polygon) == FALSE); return d; } /////////////////////////////////////////////////////////////////////////// // Copyright (C) 2015 Wizardry and Steamworks - License: GNU GPLv3 // /////////////////////////////////////////////////////////////////////////// // determines whether the path between the current positon m and the // computed next position d will intersect any two sides of the polygon vector wasPolygonPath(vector m, list polygon) { integer c = llGetListLength(polygon) - 1; vector d = wasPolygonPoint(polygon); integer i = 0; do { vector s = llList2Vector(polygon, c); vector p = llList2Vector(polygon, c-1); // project in plane if(wasSegmentIntersect( <m.x, m.y, 0>, <d.x, d.y, 0>, <s.x, s.y, 0>, <p.x, p.y, 0>)) ++i; } while(--c > 0); if(i > 1) return wasPolygonPath(m, polygon); return d; } integer _targetID = 0; moveTo(vector position) { llTargetRemove(_targetID); _targetID = llTarget(position, .1); llLookAt(position, .6, .6); llMoveToTarget(position, 1); } /////////////////////////////////////////////////////////////////////////// // these points represent the coordinates of the points that define the // // contour (permimeter) of the polgyon // /////////////////////////////////////////////////////////////////////////// list polygonPoints = [ <163.349121, 171.559189, 3400.894287>, <165.56424, 170.422821, 3400.894287>, <164.364594, 169.194382, 3400.894287>, <165.171875, 167.453903, 3400.894287>, <162.345123, 167.61731, 3400.894287> ]; default { state_entry() { llVolumeDetect(TRUE); // first move to any point within the polygon moveTo(wasPolygonPoint(polygonPoints)); } at_target(integer tnum, vector targetpos, vector ourpos) { if(tnum != _targetID) return; // now perform additional ray-cast moveTo(wasPolygonPath(llGetPos(), polygonPoints)); } }