Hi Egon,
Thanks for replying. ok i can use projectCenter3D2Dright to get the center of 3d object to 2d coords and attach the bitmap with square line. But how to get the width and height of the 3d object? i mean i want the hightlighting square line to scale if the 3d object going far or near, so the square line get bigger if the object going near and shrink if going far.
So looks like i need to get the corner top, left corner, right corner, and bottom of 3d object's vertex and using project3D2D to get the width and height?