Range/Density array in SPLINE fog !!!

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ram munjulur (ram++at++ivex3d.com)
Mon, 30 Sep 1996 10:34:18 -0400


Hello Performers :

      I am trying to get a Fog with varying density along the Range. I am trying to
go from a Zero visibility - 100% visisbility - Zero visibility - 40% - 80% and so on.
But when I plugin the values below, into the pfFogRamp() function, I see no "spikes" in
the fog density. OR atleast, how do I know that there are spikes in the fog ?

Of course, the man page on pfFog says
"These are given in
     ascending order in the arrays range and density. " But to get the my desired effect,
I am specifying a non-uniform order of Range & Density.

     In SPLINE fog implementation, do these Range/density arrays make sense?
   
      float fog_range[10] = { 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9};
      float fog_density[10] = { 1.0, 1.0, 0.0, 0.0, 1.0, 1.0 , 0.0, 0.0, 1.0, 1.0};

Is there a better way to get a variation in fog ?

Also for every draw, I keep getting a message

   "PF Warning: pfFog::setRamp() IrisGL-style ramp values: converting"

   I believe that the density values for OpenGL and IRIS GL are 1's complement of each other.
Does this conversion take place on the whole array before the array is used OR does the
conversion take place as each value in the array is used ?

Thanks in advance

Ram

ram++at++ivex3d.com
IVEX Corporation

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