Talk:Back-face culling

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[edit] Change

I've changed the following:

In computer graphics, back-face culling determines whether a polygon of a graphical object, within the field of view of the camera, is visible

to:

In computer graphics, back-face culling determines whether a polygon of a graphical object, is visible, depending on the position of the camera.

because this technique depends on the position of the camera, not on its field of view. If the back-facing polygon is outside the field of view, this technique would still cull. It just depends on the pipeline if it only culls back-facing polygons inside the field of view. - Simeon87 15:28, 12 November 2006 (UTC)

[edit] Equation

The equation Ax+By+Cz+D < 0 seems odd here in an article about backface culling. To determine of a face is visible i think it is better to use the Dot product between the view vector and the surface normal. Ax+By+Cz+D < 0 is used in view frustrum culling where it is used to see if every vertice lies within the frusrum or not. Isen't it better to just check if (C - Pv) dot Tn <= 0, where C are the camera position, pV is a vertice on the triangle and Tn is the triangle normal. If <= 0 the triangle shows its backface. Ondninja 19:55, 24 June 2007 (UTC) this is a dot product. normal=(A,B,C) distance=D and view vector=(x,y,z) —Preceding unsigned comment added by 84.16.123.194 (talk) 11:29, 15 January 2008 (UTC)