public void update() {
		// update the trail geom every 5 moves
		if (a.dropNum % p5.manager.dropSpacing == 0) {
			if (trail.size() < p5.manager.trailLength) {
				trail.add(new Vec3D(a.pos.x, a.pos.y, a.pos.z));
			} else {
				trail.remove(0);
			}
			a.dropNum = 0;
		}
		a.dropNum++;

	}