glCullFace( GL_BACK ); Does this funtion what it says?

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Started by Daywalker313 April 21, 2001 12:23 PM

5 comments, last by Daywalker313 22 years, 12 months ago

122

Author

April 21, 2001 12:23 PM

I found this functions in gl.h; glCullFace( GL_BACK ); glEnable( GL_CULL_FACE ); Do these funtions really what they mean (culling backfaces)? Do they speed up displaying TRIANGLE STRIPS etc.?

Prosper/LOADED

100

April 21, 2001 12:41 PM

Quote from the MSDN :

"
The glCullFace function specifies whether front- or back-facing facets are culled (as specified by mode) when facet culling is enabled. You enable and disable facet culling using glEnable and glDisable with the argument GL_CULL_FACE. Facets include triangles, quadrilaterals, polygons, and rectangles.
"

Daywalker313

122

Author

April 21, 2001 12:48 PM

Yes, but do these funtions speed up displaying, can I see a difference in speed?

Prosper/LOADED

100

April 21, 2001 01:29 PM

I''m not an OpenGL expert but I don''t think these functions involve any speed increase. It''s just a way to call OpenGL what order you use when you give it vertices.

/*Vince*/

122

April 21, 2001 04:02 PM

With back faces culling enabled, only one half (on average) of the faces of a standard scene will be displayed, so if your application is limited by the fill rate of your 3D card you should get a noticeable fps increase.