| 1 |
{ SCCSid "$SunId$ LBL" } |
| 2 |
|
| 3 |
{ |
| 4 |
Initialization file for Radiance. |
| 5 |
|
| 6 |
4/14/86 |
| 7 |
} |
| 8 |
|
| 9 |
{ |
| 10 |
The following are predefined: |
| 11 |
|
| 12 |
Dx, Dy, Dz - ray direction |
| 13 |
Nx, Ny, Nz - surface normal |
| 14 |
Px, Py, Pz - intersection point |
| 15 |
T - distance from start |
| 16 |
Rdot - ray dot product |
| 17 |
S - world scale |
| 18 |
Tx, Ty, Tz - world origin |
| 19 |
Ix, Iy, Iz - world i unit vector |
| 20 |
Jx, Jy, Jz - world j unit vector |
| 21 |
Kx, Ky, Kz - world k unit vector |
| 22 |
arg(n) - real arguments, arg(0) is count |
| 23 |
|
| 24 |
For brdf functions, the following are also available: |
| 25 |
|
| 26 |
NxP, NyP, NzP - perturbed surface normal |
| 27 |
RdotP - perturbed ray dot product |
| 28 |
CrP, CgP, CbP - perturbed material color |
| 29 |
|
| 30 |
Library functions: |
| 31 |
|
| 32 |
if(a, b, c) - if a positive, return b, else c |
| 33 |
|
| 34 |
select(N, a1, a2, ..) - return aN |
| 35 |
|
| 36 |
sqrt(x) - square root function |
| 37 |
|
| 38 |
sin(x), cos(x), tan(x), |
| 39 |
asin(x), acos(x), |
| 40 |
atan(x), atan2(y,x) - standard trig functions |
| 41 |
|
| 42 |
floor(x), ceil(x) - g.l.b. & l.u.b. |
| 43 |
|
| 44 |
exp(x), log(x), log10(x) - exponent and log functions |
| 45 |
|
| 46 |
erf(z), erfc(z) - error functions |
| 47 |
|
| 48 |
rand(x) - pseudo-random function (0 to 1) |
| 49 |
|
| 50 |
hermite(p0,p1,r0,r1,t) - 1-dimensional hermite polynomial |
| 51 |
|
| 52 |
noise3(x,y,z), noise3a(x,y,z), |
| 53 |
noise3b(x,y,z), noise3c(x,y,z) - noise function with gradient (-1 to 1) |
| 54 |
|
| 55 |
fnoise3(x,y,z) - fractal noise function (-1 to 1) |
| 56 |
} |
| 57 |
|
| 58 |
{ Backward compatibility } |
| 59 |
AC = arg(0); |
| 60 |
A1 = arg(1); A2 = arg(2); A3 = arg(3); A4 = arg(4); A5 = arg(5); |
| 61 |
A6 = arg(6); A7 = arg(7); A8 = arg(8); A9 = arg(9); A10 = arg(10); |
| 62 |
|
| 63 |
{ Forward compatibility (?) } |
| 64 |
D(i) = select(i, Dx, Dy, Dz); |
| 65 |
N(i) = select(i, Nx, Ny, Nz); |
| 66 |
P(i) = select(i, Px, Py, Pz); |
| 67 |
noise3d(i,x,y,z) = select(i, noise3a(x,y,z), noise3b(x,y,z), noise3c(x,y,z)); |
| 68 |
|
| 69 |
{ More robust versions of library functions } |
| 70 |
bound(a,x,b) : if(a-x, a, if(x-b, b, x)); |
| 71 |
Acos(x) : acos(bound(-1,x,1)); |
| 72 |
Asin(x) : asin(bound(-1,x,1)); |
| 73 |
Exp(x) : if(-x-60, 0, exp(x)); |
| 74 |
Sqrt(x) : if(x, sqrt(x), 0); |
| 75 |
|
| 76 |
{ Useful constants } |
| 77 |
PI : 3.14159265358979323846; |
| 78 |
DEGREE : PI/180; |
| 79 |
FTINY : 1e-7; |
| 80 |
|
| 81 |
{ Useful functions } |
| 82 |
and(a,b) : if( a, b, a ); |
| 83 |
or(a,b) : if( a, a, b ); |
| 84 |
not(a) : if( a, -1, 1 ); |
| 85 |
abs(x) : if( x, x, -x ); |
| 86 |
sgn(x) : if( x, 1, if(-x, -1, 0) ); |
| 87 |
sq(x) : x*x; |
| 88 |
max(a,b) : if( a-b, a, b ); |
| 89 |
min(a,b) : if( a-b, b, a ); |
| 90 |
inside(a,x,b) : and(x-a,b-x); |
| 91 |
frac(x) : x - floor(x); |
| 92 |
mod(n,d) : n - floor(n/d)*d; |
| 93 |
tri(n,d) : abs( d - mod(n-d,2*d) ); |
| 94 |
linterp(t,p0,p1) : (1-t)*p0 + t*p1; |
| 95 |
|
| 96 |
noop(v) = v; |
| 97 |
clip(v) = bound(0,v,1); |
| 98 |
noneg(v) = max(0,v); |
| 99 |
red(r,g,b) = r; |
| 100 |
green(r,g,b) = g; |
| 101 |
blue(r,g,b) = b; |
| 102 |
grey(r,g,b) = .3*r + .59*g + .11*b; |
| 103 |
clip_r(r,g,b) = bound(0,r,1); |
| 104 |
clip_g(r,g,b) = bound(0,g,1); |
| 105 |
clip_b(r,g,b) = bound(0,b,1); |
| 106 |
clipgrey(r,g,b) = bound(0,grey(r,g,b),1); |
| 107 |
|
| 108 |
dot(v1,v2) : v1(1)*v2(1) + v1(2)*v2(2) + v1(3)*v2(3); |
| 109 |
cross(i,v1,v2) : select(i, v1(2)*v2(3) - v1(3)*v2(2), |
| 110 |
v1(3)*v2(1) - v1(1)*v2(3), |
| 111 |
v1(1)*v2(2) - v1(2)*v2(1)); |
| 112 |
|
| 113 |
fade(near_val,far_val,dist) = far_val + |
| 114 |
if (16-dist, (near_val-far_val)/(1+dist*dist), 0); |
| 115 |
|
| 116 |
bezier(p1, p2, p3, p4, t) = p1 * (1+t*(-3+t*(3-t))) + |
| 117 |
p2 * 3*t*(1+t*(-2+t)) + |
| 118 |
p3 * 3*t*t*(1-t) + |
| 119 |
p4 * t*t*t ; |
| 120 |
|
| 121 |
bspline(pp, p0, p1, pn, t) = pp * (1/6+t*(-.5+t*(.5-1/6*t))) + |
| 122 |
p0 * (2/3+t*t*(-1+.5*t)) + |
| 123 |
p1 * (1/6+t*(.5+t*(.5-.5*t))) + |
| 124 |
pn * (1/6*t*t*t) ; |
| 125 |
|
| 126 |
turbulence(x,y,z,s) = if( s-1.01, 0, abs(noise3(x/s,y/s,z/s)*s) + |
| 127 |
turbulence(x,y,z,2*s) ); |
| 128 |
turbulencea(x,y,z,s) = if( s-1.01, 0, |
| 129 |
sgn(noise3(x/s,y/s,z/s))*noise3a(x/s,y/s,z/s) + |
| 130 |
turbulencea(x,y,z,2*s) ); |
| 131 |
turbulenceb(x,y,z,s) = if( s-1.01, 0, |
| 132 |
sgn(noise3(x/s,y/s,z/s))*noise3b(x/s,y/s,z/s) + |
| 133 |
turbulenceb(x,y,z,2*s) ); |
| 134 |
turbulencec(x,y,z,s) = if( s-1.01, 0, |
| 135 |
sgn(noise3(x/s,y/s,z/s))*noise3c(x/s,y/s,z/s) + |
| 136 |
turbulencec(x,y,z,2*s) ); |
