How is culling done

Hi Everybody,

I am using FlightGear 0.9.4 Simulation Software.

We are reading a data file which is in binary format(*.btg) and adding every object
in scene graph(Tree structure).
Now our scene graph contains all the objects which will be used further for culling
and rendering
Object contained in the scene graph are: modal branch, aircraft branch , terrain branch
and different lightening.

We are using frustum culling technique . In constuctor we are setting the frustum values
Ortho=false;
nnear=SG_one
ffar=1000000.0f
hfv=SG_45
vfov=SG_45

I have lot of doubts………

1. How are we setting the frustums six plane and where (are we placing in the scene
   graph)
2. How are we selecting part of the objects from scene graph and placing it in frustum
   Which is being used for further culling and rendering.
3. A concept called extend sphere over sphere is used. I didn’t get the concept.

If any one knows about culling and rendering plz explain me in detail .

Plz explain me the concept of Bounding Box also

Hemalatha

I’d suggest you go to the beginners’ forum or better to a general graphics forum. Or you could just read some of the thousands of articles (google, gamedev.net) on the subject…