@Rajkumar I've got some time to spend on your issue, here's what happens, there're two things: 1) The boundingInfo of you line mesh exactly fits the line, there's no "additional margin" so your mesh is rejected if the mouse pointer is too far. In another words, the engine doesn't make the linesMesh intersection because the ray corresponding to the mouse cursor is outside the boundingInfo of the lineMesh. That is why I've created a boundingBias property in the Geometry class: to "extend" the