[Radiance-general] water - any news???

[Greg Ward]

Hi Rob,

If you type "make" in the unpacked directory, the enclosed Makefile  
(attached with minor tweaks) will run the following commands:

oconv -f pool_surface.rad catchpool.rad > catchscene.oct
vwrays -pj .6 -vf pool_par.vf -x 500 -y 500 -ff \
| rtcontrib -w -ffc -c -fo -n 1 \
                 -f pool_coords.cal -o %s_caustics.pic \
                 -b floor_bin -bn 7500 -x 50 -y 150 -m floor \
                 -b s_wall_bin -bn 1500 -x 50 -y 30 -m s_wall \
                 -b n_wall_bin -bn 1500 -x 50 -y 30 -m n_wall \
                 -b e_wall_bin -bn 4500 -x 150 -y 30 -m e_wall \
                 -b w_wall_bin -bn 4500 -x 150 -y 30 -m w_wall \
                 catchscene.oct
rm catchscene.oct
rad -o x11 poolscene.rif
	oconv sky.rad glowpool.rad pool_surface.rad > poolscene.oct
         rvu -vp -20 20 20 -vd 20 -20 -20 -vh 30 -vv 20 -ps 16 -pt . 
16 -dp 64 -ar 38 -ds 0 -dt .2 -dc .25 -dr 0 -sj 0 -st .5 -aa .3 -ad  
256 -as 0 -av 17 17 17 -lr 6 -lw .01 -R poolscene.rif -o x11 -pe .03  
poolscene.oct

This will produce 5 Radiance pictures, one for each wall.  Since the  
defaults for rtcontrib set -ab 1, it will also consider some mutual  
interactions from the sunlight cast along the given parallel view  
(pool_par.vf).  It does not include sky illuminance, which is  
probably a minor component, anyway.  Adding that in would require a  
more sophisticated bombarding sampler than vwrays, or a mixfunc  
rather than a glow surface on the remodeling end.

The other cool thing the new rtcontrib -c option facilitates is  
optical system modeling, as in custom-designed luminaires.  It would  
be interesting to compare to more specialized (& sophisticated)  
commercial ray-tracing systems.

-Greg

P.S.  You need to download the latest HEAD of src/util/rtcontrib.c  
and recompile for this to work.

> From: "Shakespeare, Robert A." <shakespe at indiana.edu>
> Date: November 17, 2007 6:52:23 AM PST
>
> How do you generate the floor_caustics.pic from the files you  
> uploaded? This is most interesting!
>
> -Rob Shakespeare
---------------------
#
# A swimming pool with caustics on the bottom
#

NPROCS = 1

CAUSTICS = floor_caustics.pic s_wall_caustics.pic n_wall_caustics.pic \
         e_wall_caustics.pic w_wall_caustics.pic

OBJF =

SCENEF = pool_surface.rad

view:   glowpool.rad sky.rad $(SCENEF) $(OBJF) $(CAUSTICS)
         rad -o x11 poolscene.rif

pics:   glowpool.rad sky.rad $(SCENEF) $(OBJF) $(CAUSTICS)
         rad -N $(NPROCS) poolscene.rif

$(CAUSTICS):    catchpool.rad $(SCENEF) $(OBJF) pool_par.vf
         oconv -f $(SCENEF) catchpool.rad > catchscene.oct
         vwrays -pj .6 -vf pool_par.vf -x 500 -y 500 -ff \
                 | rtcontrib -w -ffc -c -fo -n $(NPROCS) \
                         -f pool_coords.cal -o %s_caustics.pic \
                         -b floor_bin -bn 7500 -x 50 -y 150 -m floor \
                         -b s_wall_bin -bn 1500 -x 50 -y 30 -m s_wall \
                         -b n_wall_bin -bn 1500 -x 50 -y 30 -m n_wall \
                         -b e_wall_bin -bn 4500 -x 150 -y 30 -m e_wall \
                         -b w_wall_bin -bn 4500 -x 150 -y 30 -m w_wall \
                         catchscene.oct
         rm catchscene.oct