How to use PointerEnter on 3D Object

I able to use PointerEnter function of event trigger on 2D object such as button,image, etc. When I moved the cursor to 2d object the event is worked. But, I try to do PointerEnter on 3D object that is my own model, but it not work . When I move the cursor to the 3d object then nothing happen.

I need your help.

Use OnMouseDown :smiley: