| 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(log(1/p/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 } |
