On 2002.04.04 09:08 Keith Whitwell wrote: > On Thu, 4 Apr 2002 01:56:22 +0100 > José Fonseca <[EMAIL PROTECTED]> wrote: > > > ... > > > the further away is the vertex more its color is nearer to the fog > > background color. Since the colors are interpolated in the triangle > this > > gave the impression of fog. > > > > But the OpenGL spec says that the fog color is calculated on a _pixel_ > > basis and not on a _vertex_ basis. Indeed the result is different, > > especially in long polygons that span from the front way to the back. > > > Actually I think it gives you scope to do either.
Well the Opengl 1.3, sec 3.10 says: "Further, f need not be computed at each fragment, but may be computed at each vertex and interpolated as other data are.", but it also says "If enabled, fog blends a fog color with a rasterized fragment s post-texturing color using a blending factor f." Since it's applied after on the pipeline I'm not sure that the results will be the same, even without texturing.. > The issue with adding > fog into the vertex colors is what happens when texturing is turned on - > the vertex color may not even contribute to the color of the generated > fragments. I see, it depends of the texture environment... so unless there is a way around it we will have to fallback to software on these no matter what. > > Keith > José Fonseca _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
