* @return intersection data parcel
*/
public IsectData3D intersectAtPoint(float x, float z) {
float xx = x / scale.x + width * 0.5f;
float zz = z / scale.y + depth * 0.5f;
IsectData3D isec = new IsectData3D();
if (xx >= 0 && xx < width && zz >= 0 && zz < depth) {
int x2 = (int) MathUtils.min(xx + 1, width - 1);
int z2 = (int) MathUtils.min(zz + 1, depth - 1);
Vec3D a = getVertexAtCell((int) xx, (int) zz);
Vec3D b = getVertexAtCell(x2, (int) zz);