9 |
|
Nx, Ny, Nz - surface normal |
10 |
|
Px, Py, Pz - intersection point |
11 |
|
T - distance from start |
12 |
+ |
Ts - single ray (shadow) distance |
13 |
|
Rdot - ray dot product |
14 |
|
S - world scale |
15 |
|
Tx, Ty, Tz - world origin |
67 |
|
bound(a,x,b) : if(a-x, a, if(x-b, b, x)); |
68 |
|
Acos(x) : acos(bound(-1,x,1)); |
69 |
|
Asin(x) : asin(bound(-1,x,1)); |
70 |
< |
Exp(x) : if(-x-60, 0, exp(x)); |
70 |
> |
Exp(x) : if(-x-100, 0, exp(x)); |
71 |
|
Sqrt(x) : if(x, sqrt(x), 0); |
72 |
|
|
73 |
|
{ Useful constants } |
92 |
|
|
93 |
|
noop(v) = v; |
94 |
|
clip(v) = bound(0,v,1); |
95 |
< |
noneg(v) = max(0,v); |
96 |
< |
red(r,g,b) = r; |
97 |
< |
green(r,g,b) = g; |
98 |
< |
blue(r,g,b) = b; |
99 |
< |
grey(r,g,b) = .3*r + .59*g + .11*b; |
95 |
> |
noneg(v) = if(v,v,0); |
96 |
> |
red(r,g,b) = if(r,r,0); |
97 |
> |
green(r,g,b) = if(g,g,0); |
98 |
> |
blue(r,g,b) = if(b,b,0); |
99 |
> |
grey(r,g,b) = noneg(.263*r + .655*g + .082*b); |
100 |
|
clip_r(r,g,b) = bound(0,r,1); |
101 |
|
clip_g(r,g,b) = bound(0,g,1); |
102 |
|
clip_b(r,g,b) = bound(0,b,1); |
131 |
|
turbulencec(x,y,z,s) = if( s-1.01, 0, |
132 |
|
sgn(noise3(x/s,y/s,z/s))*noise3c(x/s,y/s,z/s) + |
133 |
|
turbulencec(x,y,z,2*s) ); |
134 |
+ |
|
135 |
+ |
{ Normal distribution from uniform range (0,1) } |
136 |
+ |
|
137 |
+ |
un2`private(t) : t - (2.515517+t*(.802853+t*.010328))/ |
138 |
+ |
(1+t*(1.432788+t*(.189269+t*.001308))) ; |
139 |
+ |
un1`private(p) : un2`private(sqrt(-2*log(p))) ; |
140 |
+ |
|
141 |
+ |
unif2norm(p) : if( .5-p, un1`private(p), -un1`private(1-p) ) ; |
142 |
+ |
|
143 |
+ |
nrand(x) = unif2norm(rand(x)); |
144 |
|
|
145 |
|
{ Local (u,v) coordinates for planar surfaces } |
146 |
|
crosslen`private = Nx*Nx + Ny*Ny; |