Forward Avatar Intersect

// Forward sector avatar intersect // Ordinal Malaprop // 2006-09-22 // Should report the first avatar whose bounding box "sort of" // intersects the forward vector of the toucher, adjusted for eye level. // An assumption is made for simplicity that the box is actually a // cylinder; this won't make any real difference in practice. default { touch_start(integer n) { llSensor("", NULL_KEY, AGENT, 96.0, PI_BY_TWO); } sensor(integer n) { // Adjust position for eye level vector mypos = llGetPos() + <0.0, 0.0, 0.75>; // Current forward vector vector fwd = llRot2Fwd(llGetRot()); integer f = 0; key target = NULL_KEY; // key of identified target do { key id = llDetectedKey(f); // This returns a list; we assume the avatar has // a bounding box that is symmetrical about their axes // and calculate its size based on the maximum corner. // Diameter of the "cylinder" is based on width. list box_list = llGetBoundingBox(id); vector pos = llDetectedPos(f); vector box = llList2Vector(box_list, 1); // Nearest point along the forward axis to the target's // position vector nearest = fwd * (fwd * (pos - mypos)) + mypos; // Find the distances of this from target pos on the XY plane // and the Z axis float z_diff = llVecMag(<0.0, 0.0, nearest.z> - <0.0, 0.0, pos.z>); float xy_diff = llVecMag( - ); llOwnerSay("Checking " + llDetectedName(f) + " @ " + (string)pos + ", nearest pos " + (string)nearest + ", z_diff=" + (string)z_diff + ", xy_diff=" + (string)xy_diff + ", box=" + (string)box); if (xy_diff <= (box.y + box.x) / 2 && z_diff <= box.z) { // projection of forward vector within box target = id; llOwnerSay("Hit " + llDetectedName(0)); } } while (++f < n && target == NULL_KEY); if (target == NULL_KEY) { llOwnerSay("Missed"); } } no_sensor() { llOwnerSay("Nothing here, you fool"); } }