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09-17-2002, 11:03 AM
hi,
I am doing my masters in CAD/CAM. I am working on a project involving reconstruction of 3 dimensional drawings from 2 dimensional/orthographic views. The code is prepared using OpenGl.
The problem is to make a rectangle for sweep selection of the objects drawn on the screen using a mouse. Please guide me on the topic as i am not getting any information regarding the problem.
thank you
rajesh malik

Robbo
09-18-2002, 12:23 AM
Heres a quickie: assuming you already have code to rubber-band a rectangle selection area in the scene, you can generate a bounding box by back-projecting the corner points of the box into the scene - then you simply check to intersection or containment of any objects bounding sphere or box with the scene.

There are algos' for box-sphere and box-box intersection testing on the net - there are also tuts on how to `fire a ray' from the mouse pointer back into the scene to get position\vector information in 3D from your 2D mouse position coords.

Hope this helps http://www.opengl.org/discussion_boards/ubb/wink.gif