| 3 |
|
{ |
| 4 |
|
Initialization file for Radiance. |
| 5 |
|
|
| 6 |
– |
4/14/86 |
| 7 |
– |
} |
| 8 |
– |
|
| 9 |
– |
{ |
| 6 |
|
The following are predefined: |
| 7 |
|
|
| 8 |
|
Dx, Dy, Dz - ray direction |
| 66 |
|
bound(a,x,b) : if(a-x, a, if(x-b, b, x)); |
| 67 |
|
Acos(x) : acos(bound(-1,x,1)); |
| 68 |
|
Asin(x) : asin(bound(-1,x,1)); |
| 69 |
< |
Exp(x) : if(-x-60, 0, exp(x)); |
| 69 |
> |
Exp(x) : if(-x-100, 0, exp(x)); |
| 70 |
|
Sqrt(x) : if(x, sqrt(x), 0); |
| 71 |
|
|
| 72 |
|
{ Useful constants } |
| 91 |
|
|
| 92 |
|
noop(v) = v; |
| 93 |
|
clip(v) = bound(0,v,1); |
| 94 |
< |
noneg(v) = max(0,v); |
| 95 |
< |
red(r,g,b) = r; |
| 96 |
< |
green(r,g,b) = g; |
| 97 |
< |
blue(r,g,b) = b; |
| 94 |
> |
noneg(v) = if(v,v,0); |
| 95 |
> |
red(r,g,b) = if(r,r,0); |
| 96 |
> |
green(r,g,b) = if(g,g,0); |
| 97 |
> |
blue(r,g,b) = if(b,b,0); |
| 98 |
|
grey(r,g,b) = .3*r + .59*g + .11*b; |
| 99 |
|
clip_r(r,g,b) = bound(0,r,1); |
| 100 |
|
clip_g(r,g,b) = bound(0,g,1); |
| 130 |
|
turbulencec(x,y,z,s) = if( s-1.01, 0, |
| 131 |
|
sgn(noise3(x/s,y/s,z/s))*noise3c(x/s,y/s,z/s) + |
| 132 |
|
turbulencec(x,y,z,2*s) ); |
| 133 |
+ |
|
| 134 |
+ |
{ Normal distribution from uniform range (0,1) } |
| 135 |
+ |
|
| 136 |
+ |
un2`private(t) : t - (2.515517+t*(.802853+t*.010328))/ |
| 137 |
+ |
(1+t*(1.432788+t*(.189269+t*.001308))) ; |
| 138 |
+ |
un1`private(p) : un2`private(sqrt(-2*log(p))) ; |
| 139 |
+ |
|
| 140 |
+ |
unif2norm(p) : if( .5-p, un1`private(p), -un1`private(1-p) ) ; |
| 141 |
+ |
|
| 142 |
+ |
nrand(x) = unif2norm(rand(x)); |
| 143 |
+ |
|
| 144 |
+ |
{ Local (u,v) coordinates for planar surfaces } |
| 145 |
+ |
crosslen`private = Nx*Nx + Ny*Ny; |
| 146 |
+ |
{ U is distance from origin in XY-plane } |
| 147 |
+ |
U = if( crosslen`private - FTINY, |
| 148 |
+ |
(Py*Nx - Px*Ny)/crosslen`private, |
| 149 |
+ |
Px); |
| 150 |
+ |
{ V is defined so that N = U x V } |
| 151 |
+ |
V = if( crosslen`private - FTINY, |
| 152 |
+ |
Pz - Nz*(Px*Nx + Py*Ny)/crosslen`private, |
| 153 |
+ |
Py); |
