cal/cal/veil.cal

{
        Add veiling glare caused by bright sources to an image.
        Input is direction and illuminances of sources as may
        be determined with the Radiance program, findglare(1).

        N :             Number of glaring sources
        SDx(i) :        x component of normalized direction to source i
        SDy(i) :        y component of same
        SDz(i) :        z component of same
        I(i) :          illuminance (lux) due to i in source's direction
                                (multiply the luminance by the solid angle)

        An automated way to get this is to send the output of findglare
        into tabfunc, i.e.:

                findglare [options] | sed -e '1,/^BEGIN glare source$/d' \
                                -e '/^END glare source$/,$d' \
                        | rcalc -e '$1=recno;$2=$1;$3=$2;$4=$3;$5=$4*$5' \
                        | tabfunc SDx SDy SDz I > glrsrc.cal

        Then, simply define N with "N:I(0)" either with a -e option to
        pcomb or as an additional line in glrsrc.cal, i.e.:

                pcomb -f glrsrc.cal -e 'N:I(0)' -f veil.cal orig.pic > veil.pic
}

bound(a,x,b) : if(a-x, a, if(x-b, b, x));
Acos(x) : acos(bound(-1,x,1));

{ mul(t) : if(.5*PI/180-t, 9.2/.5^2, 9.2/(180/PI)^2/(t*t)); }

mul(t) : if(1.58724464*PI/180-t, 9.2/((if(t-.00291,t,.00291)*(180/PI))^3.44),
                9.2/((180/PI*t)*(1.5+180/PI*t)));

Dx1 = Dx(1); Dy1 = Dy(1); Dz1 = Dz(1);          { minor optimization }

angle(i) = Acos(SDx(i)*Dx1+SDy(i)*Dy1+SDz(i)*Dz1);

sum(i) = if(i-.5, mul(angle(i))*I(i)+sum(i-1), 0);

veil = le(1)/WE * sum(N);

ro = ri(1) + veil;
go = gi(1) + veil;
bo = bi(1) + veil;
Revision:	1.1
Committed:	Sat Feb 22 02:07:21 2003 UTC (21 years, 2 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R2, rad4R2P2, rad5R0, rad5R1, rad3R7P2, rad3R7P1, rad4R2, rad4R1, rad4R0, rad3R5, rad3R6, rad3R6P1, rad3R8, rad3R9, rad4R2P1
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	Content
1	{
2	Add veiling glare caused by bright sources to an image.
3	Input is direction and illuminances of sources as may
4	be determined with the Radiance program, findglare(1).
5
6	N : Number of glaring sources
7	SDx(i) : x component of normalized direction to source i
8	SDy(i) : y component of same
9	SDz(i) : z component of same
10	I(i) : illuminance (lux) due to i in source's direction
11	(multiply the luminance by the solid angle)
12
13	An automated way to get this is to send the output of findglare
14	into tabfunc, i.e.:
15
16	findglare [options] \| sed -e '1,/^BEGIN glare source$/d' \
17	-e '/^END glare source$/,$d' \
18	\| rcalc -e '$1=recno;$2=$1;$3=$2;$4=$3;$5=$4*$5' \
19	\| tabfunc SDx SDy SDz I > glrsrc.cal
20
21	Then, simply define N with "N:I(0)" either with a -e option to
22	pcomb or as an additional line in glrsrc.cal, i.e.:
23
24	pcomb -f glrsrc.cal -e 'N:I(0)' -f veil.cal orig.pic > veil.pic
25	}
26
27	bound(a,x,b) : if(a-x, a, if(x-b, b, x));
28	Acos(x) : acos(bound(-1,x,1));
29
30	{ mul(t) : if(.5PI/180-t, 9.2/.5^2, 9.2/(180/PI)^2/(tt)); }
31
32	mul(t) : if(1.58724464PI/180-t, 9.2/((if(t-.00291,t,.00291)(180/PI))^3.44),
33	9.2/((180/PIt)(1.5+180/PI*t)));
34
35	Dx1 = Dx(1); Dy1 = Dy(1); Dz1 = Dz(1); { minor optimization }
36
37	angle(i) = Acos(SDx(i)Dx1+SDy(i)Dy1+SDz(i)*Dz1);
38
39	sum(i) = if(i-.5, mul(angle(i))*I(i)+sum(i-1), 0);
40
41	veil = le(1)/WE * sum(N);
42
43	ro = ri(1) + veil;
44	go = gi(1) + veil;
45	bo = bi(1) + veil;