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root/radiance/ray/src/rt/rayinit.cal
Revision: 2.14
Committed: Tue Mar 11 19:29:05 2003 UTC (21 years ago) by greg
Branch: MAIN
CVS Tags: rad3R7P2, rad3R7P1, rad4R1, rad4R0, rad3R5, rad3R6, rad3R6P1, rad3R8, rad3R9
Changes since 2.13: +5 -1 lines
Log Message:
Changed alias handling to allow tracking, fixed freeobjects() and do_irrad bugs

File Contents

# Content
1 { RCSid $Id$ }
2 {
3 Initialization file for Radiance.
4
5 The following are predefined:
6
7 Dx, Dy, Dz - ray direction
8 Nx, Ny, Nz - surface normal
9 Px, Py, Pz - intersection point
10 T - distance from start
11 Ts - single ray (shadow) distance
12 Rdot - ray dot product
13 S - world scale
14 Tx, Ty, Tz - world origin
15 Ix, Iy, Iz - world i unit vector
16 Jx, Jy, Jz - world j unit vector
17 Kx, Ky, Kz - world k unit vector
18 arg(n) - real arguments, arg(0) is count
19
20 For mesh objects, the following are available:
21
22 Lu, Lv - local (u,v) coordinates
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 For prism1 and prism2 types, the following are available:
31
32 DxA, DyA, DzA - direction to target light source
33
34 Library functions:
35
36 if(a, b, c) - if a positive, return b, else c
37
38 select(N, a1, a2, ..) - return aN
39
40 sqrt(x) - square root function
41
42 sin(x), cos(x), tan(x),
43 asin(x), acos(x),
44 atan(x), atan2(y,x) - standard trig functions
45
46 floor(x), ceil(x) - g.l.b. & l.u.b.
47
48 exp(x), log(x), log10(x) - exponent and log functions
49
50 erf(z), erfc(z) - error functions
51
52 rand(x) - pseudo-random function (0 to 1)
53
54 hermite(p0,p1,r0,r1,t) - 1-dimensional hermite polynomial
55
56 noise3(x,y,z), noise3x(x,y,z),
57 noise3y(x,y,z), noise3z(x,y,z) - noise function with gradient (-1 to 1)
58
59 fnoise3(x,y,z) - fractal noise function (-1 to 1)
60 }
61
62 { Backward compatibility }
63 AC = arg(0);
64 A1 = arg(1); A2 = arg(2); A3 = arg(3); A4 = arg(4); A5 = arg(5);
65 A6 = arg(6); A7 = arg(7); A8 = arg(8); A9 = arg(9); A10 = arg(10);
66
67 noise3a(x,y,z) : noise3x(x,y,z);
68 noise3b(x,y,z) : noise3y(x,y,z);
69 noise3c(x,y,z) : noise3z(x,y,z);
70
71 { Forward compatibility (?) }
72 D(i) = select(i, Dx, Dy, Dz);
73 N(i) = select(i, Nx, Ny, Nz);
74 P(i) = select(i, Px, Py, Pz);
75 noise3d(i,x,y,z) : select(i, noise3x(x,y,z), noise3y(x,y,z), noise3z(x,y,z));
76
77 { More robust versions of library functions }
78 bound(a,x,b) : if(a-x, a, if(x-b, b, x));
79 Acos(x) : acos(bound(-1,x,1));
80 Asin(x) : asin(bound(-1,x,1));
81 Atan2(y,x) : if(x*x+y*y, atan2(y,x), 0);
82 Exp(x) : if(-x-100, 0, exp(x));
83 Sqrt(x) : if(x, sqrt(x), 0);
84
85 { Useful constants }
86 PI : 3.14159265358979323846;
87 DEGREE : PI/180;
88 FTINY : 1e-7;
89
90 { Useful functions }
91 and(a,b) : if( a, b, a );
92 or(a,b) : if( a, a, b );
93 not(a) : if( a, -1, 1 );
94 xor(a,b) : if( a, not(b), b );
95 abs(x) : if( x, x, -x );
96 sgn(x) : if( x, 1, if(-x, -1, 0) );
97 sq(x) : x*x;
98 max(a,b) : if( a-b, a, b );
99 min(a,b) : if( a-b, b, a );
100 inside(a,x,b) : and(x-a,b-x);
101 frac(x) : x - floor(x);
102 mod(n,d) : n - floor(n/d)*d;
103 tri(n,d) : abs( d - mod(n-d,2*d) );
104 linterp(t,p0,p1) : (1-t)*p0 + t*p1;
105
106 noop(v) : v;
107 clip(v) : bound(0,v,1);
108 noneg(v) : if(v,v,0);
109 red(r,g,b) : if(r,r,0);
110 green(r,g,b) : if(g,g,0);
111 blue(r,g,b) : if(b,b,0);
112 grey(r,g,b) : noneg(.265074126*r + .670114631*g + .064811243*b);
113 clip_r(r,g,b) : bound(0,r,1);
114 clip_g(r,g,b) : bound(0,g,1);
115 clip_b(r,g,b) : bound(0,b,1);
116 clipgrey(r,g,b) : min(grey(r,g,b),1);
117
118 dot(v1,v2) : v1(1)*v2(1) + v1(2)*v2(2) + v1(3)*v2(3);
119 cross(i,v1,v2) : select(i, v1(2)*v2(3) - v1(3)*v2(2),
120 v1(3)*v2(1) - v1(1)*v2(3),
121 v1(1)*v2(2) - v1(2)*v2(1));
122
123 fade(near_val,far_val,dist) : far_val +
124 if (16-dist, (near_val-far_val)/(1+dist*dist), 0);
125
126 bezier(p1, p2, p3, p4, t) : p1 * (1+t*(-3+t*(3-t))) +
127 p2 * 3*t*(1+t*(-2+t)) +
128 p3 * 3*t*t*(1-t) +
129 p4 * t*t*t ;
130
131 bspline(pp, p0, p1, pn, t) : pp * (1/6+t*(-.5+t*(.5-1/6*t))) +
132 p0 * (2/3+t*t*(-1+.5*t)) +
133 p1 * (1/6+t*(.5+t*(.5-.5*t))) +
134 pn * (1/6*t*t*t) ;
135
136 turbulence(x,y,z,s) : if( s-1.01, 0, abs(noise3(x/s,y/s,z/s)*s) +
137 turbulence(x,y,z,2*s) );
138 turbulencex(x,y,z,s) : if( s-1.01, 0,
139 sgn(noise3(x/s,y/s,z/s))*noise3x(x/s,y/s,z/s) +
140 turbulencex(x,y,z,2*s) );
141 turbulencey(x,y,z,s) : if( s-1.01, 0,
142 sgn(noise3(x/s,y/s,z/s))*noise3y(x/s,y/s,z/s) +
143 turbulencey(x,y,z,2*s) );
144 turbulencez(x,y,z,s) : if( s-1.01, 0,
145 sgn(noise3(x/s,y/s,z/s))*noise3z(x/s,y/s,z/s) +
146 turbulencez(x,y,z,2*s) );
147
148 { Normal distribution from uniform range (0,1) }
149
150 un2`P(t) : t - (2.515517+t*(.802853+t*.010328))/
151 (1+t*(1.432788+t*(.189269+t*.001308))) ;
152 un1`P(p) : un2`P(sqrt(-2*log(p))) ;
153
154 unif2norm(p) : if( .5-p, -un1`P(p), un1`P(1-p) ) ;
155
156 nrand(x) = unif2norm(rand(x));
157
158 { Local (u,v) coordinates for planar surfaces }
159 crosslen`P = Nx*Nx + Ny*Ny;
160 { U is distance from projected Z-axis }
161 U = if( crosslen`P - FTINY,
162 (Py*Nx - Px*Ny)/crosslen`P,
163 Px);
164 { V is defined so that N = U x V }
165 V = if( crosslen`P - FTINY,
166 Pz - Nz*(Px*Nx + Py*Ny)/crosslen`P,
167 Py);