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sobeit

OpenGL very small variance value from Variance Shadow Mapping

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Sorry, it was a bug in my code. How can I delete the thread?

 

Hi, I'm trying to implement Variance Shadow Mapping, but get very small variance and Chebychev's upper bound, which results in sharp shadow edges. And I've turned on OpenGL texture linear filtering. Could anyone help out on this? Thanks.

 

#version 400


layout(location = 0) out vec2 moments;


void main()
{

      float depth = gl_FragCoord.z/*  * 0.5 + 0.5 */;


      float moment1 = depth;
      float moment2 = depth * depth;


      moments = vec2(moment1, moment2);
}
float chebyshevUpperBound(vec3 shadowPos)
{
vec2 moments = texture(shadowMap[0], shadowPos.xy).rg;


float bias = 0.000028;
if (shadowPos.z - bias <= moments[0])
return 1.0 ;


float variance = moments.y - (moments.x * moments.x);
variance = max(variance, 0.00002);


float d = v2fShadowPos.z - moments.x;
// this value is really small !!!!
float p_max = variance / (variance + d * d);


return p_max;
}
Edited by sobeit

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