Ray Tracing op GPU en CPU - EDM - UHasselt

struct outputs {
float4 h P o s i t i o n : POSITION ;
float4 fresnelTerm : COLOR0;
float4 r e f r a c t V e c : TEXCOORD0;
float4 r e f l e c t V e c : TEXCOORD1;
} ;
// f r e s n e l approximation
fixed f a s t f r e s n e l ( float3 I , float3 N, float3 f r e s n e l V a l u e s ) {
fixed power = f r e s n e l V a l u e s . x ;
fixed s c a l e = f r e s n e l V a l u e s . y ;
fixed b i a s = f r e s n e l V a l u e s . z ;
return b i a s + pow ( 1 . 0 − dot ( I , N) , power ) ∗ s c a l e ;
}
outputs main (
inputs IN ,
uniform float4x4 ModelViewProj ,
uniform float4x4 ModelView ,
uniform float4x4 ModelViewIT ,
uniform float theta ) {
outputs OUT;
OUT. h P o s i t i o n = mul ( ModelViewProj , IN . P o s i t i o n ) ;
// convert p o s i t i o n and normal i n t o a p p r o p r i a t e spaces
float3 eyeToVert = mul ( ModelView , IN . P o s i t i o n ) . xyz ;
eyeToVert = normalize ( eyeToVert ) ;
float3 normal = mul ( ModelViewIT , IN . Normal ) . xyz ;
normal = normalize ( normal ) ;
OUT. r e f r a c t V e c . xyz = r e f r a c t ( eyeToVert , normal , theta ) ;
OUT. r e f r a c t V e c .w = 1 ;
OUT. r e f l e c t V e c . xyz = r e f l e c t ( eyeToVert , normal ) ;
OUT. r e f l e c t V e c .w = 1 ;
// c a l c u l a t e the f r e s n e l r e f l e c t i o n
OUT. fresnelTerm = f a s t f r e s n e l (−eyeToVert , normal ,
float3 ( 5 . 0 , 1 . 0 , 0 . 0 ) ) ;
return OUT;
}
Codefragment 4.2: Cg vertex shader voor refractie
float4 main ( in float3 r e f r a c t V e c : TEXCOORD0,
in float3 r e f l e c t V e c : TEXCOORD1,
in float3 fresnelTerm : COLOR0,
uniform samplerCUBE environmentMaps [ 2 ] ,
uniform float e n a b l e R e f r a c t i o n ,
uniform float e n a b l e F r e s n e l ) : COLOR {
float3 r e f r a c t C o l o r = texCUBE( environmentMaps [ 0 ] ,
r e f r a c t V e c ) . rgb ;
float3 r e f l e c t C o l o r = texCUBE( environmentMaps [ 1 ] ,
r e f l e c t V e c ) . rgb ;
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