54 |
|
extern double salbedo; /* global scattering albedo */ |
55 |
|
|
56 |
|
|
57 |
+ |
static double |
58 |
+ |
mylog(x) /* special log for extinction coefficients */ |
59 |
+ |
double x; |
60 |
+ |
{ |
61 |
+ |
if (x < 1e-40) |
62 |
+ |
return(-100.); |
63 |
+ |
if (x >= 1.) |
64 |
+ |
return(0.); |
65 |
+ |
return(log(x)); |
66 |
+ |
} |
67 |
+ |
|
68 |
+ |
|
69 |
|
m_dielectric(m, r) /* color a ray which hit a dielectric interface */ |
70 |
|
OBJREC *m; |
71 |
|
register RAY *r; |
97 |
|
dnorm[0] = -dnorm[0]; |
98 |
|
dnorm[1] = -dnorm[1]; |
99 |
|
dnorm[2] = -dnorm[2]; |
100 |
< |
setcolor(r->cext, -log(m->oargs.farg[0]*colval(r->pcol,RED)), |
101 |
< |
-log(m->oargs.farg[1]*colval(r->pcol,GRN)), |
102 |
< |
-log(m->oargs.farg[2]*colval(r->pcol,BLU))); |
100 |
> |
setcolor(r->cext, -mylog(m->oargs.farg[0]*colval(r->pcol,RED)), |
101 |
> |
-mylog(m->oargs.farg[1]*colval(r->pcol,GRN)), |
102 |
> |
-mylog(m->oargs.farg[2]*colval(r->pcol,BLU))); |
103 |
|
r->albedo = 0.; |
104 |
|
r->gecc = 0.; |
105 |
|
if (m->otype == MAT_INTERFACE) { |
106 |
|
setcolor(ctrans, |
107 |
< |
-log(m->oargs.farg[4]*colval(r->pcol,RED)), |
108 |
< |
-log(m->oargs.farg[5]*colval(r->pcol,GRN)), |
109 |
< |
-log(m->oargs.farg[6]*colval(r->pcol,BLU))); |
107 |
> |
-mylog(m->oargs.farg[4]*colval(r->pcol,RED)), |
108 |
> |
-mylog(m->oargs.farg[5]*colval(r->pcol,GRN)), |
109 |
> |
-mylog(m->oargs.farg[6]*colval(r->pcol,BLU))); |
110 |
|
talb = 0.; |
111 |
|
} else { |
112 |
|
copycolor(ctrans, cextinction); |
115 |
|
} else { /* outside */ |
116 |
|
nratio = 1.0 / nratio; |
117 |
|
|
118 |
< |
setcolor(ctrans, -log(m->oargs.farg[0]*colval(r->pcol,RED)), |
119 |
< |
-log(m->oargs.farg[1]*colval(r->pcol,GRN)), |
120 |
< |
-log(m->oargs.farg[2]*colval(r->pcol,BLU))); |
118 |
> |
setcolor(ctrans, -mylog(m->oargs.farg[0]*colval(r->pcol,RED)), |
119 |
> |
-mylog(m->oargs.farg[1]*colval(r->pcol,GRN)), |
120 |
> |
-mylog(m->oargs.farg[2]*colval(r->pcol,BLU))); |
121 |
|
talb = 0.; |
122 |
|
if (m->otype == MAT_INTERFACE) { |
123 |
|
setcolor(r->cext, |
124 |
< |
-log(m->oargs.farg[4]*colval(r->pcol,RED)), |
125 |
< |
-log(m->oargs.farg[5]*colval(r->pcol,GRN)), |
126 |
< |
-log(m->oargs.farg[6]*colval(r->pcol,BLU))); |
124 |
> |
-mylog(m->oargs.farg[4]*colval(r->pcol,RED)), |
125 |
> |
-mylog(m->oargs.farg[5]*colval(r->pcol,GRN)), |
126 |
> |
-mylog(m->oargs.farg[6]*colval(r->pcol,BLU))); |
127 |
|
r->albedo = 0.; |
128 |
|
r->gecc = 0.; |
129 |
|
} |