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Figure 11: Volume of glyphs

This requires an actual DT-MRI dataset, which is available online. The following commmand creates a smaller, cropped, volume that will be visualized:

unu resample -i ../gk2-rcc-mask.nhdr \
   -s = x0.75 x0.75 x0.75 -k cubic:1,0 \
 | unu crop -min 0 56 0 0 -max M M M M -o half-small.nrrd

Then "tend glyph" is used to make the rendering. You may want to decrease the image sizes (down from 1700x1700) as this ray-tracer is not currently multi-threaded.

setenv FR "-7 4 -1"
setenv UP "0 3 -10"

echo "1 1 1 1 3 -5.5 -7" \
 | emap -i - -amb 0 0 0 -fr $FR -up $UP -rh -o tmp0.nrrd
unu 2op ^ tmp0.nrrd 1.8 \
 | unu 2op - 1 - \
 | unu 2op x - 3.14159 \
 | unu 1op cos \
 | unu 2op + - 1 \
 | unu 2op / - 2 -o tmp1.nrrd
unu 3op lerp 0.7 tmp0.nrrd tmp1.nrrd -o emap.nrrd

alias GLYPH tend glyph -rt -a ca1 -atr 0.5 -ctr 0.999 \
   -fr $FR -up $UP -rh -or -ur -0.20 0.39 -vr -0.30 0.29 \
   -am 1.0 -ga fa -sat 0.0 -emap emap.nrrd -gam 1.0 -bg 0 0 0 \
   -is 1700 1700 -ns 4 -o -

tend evalclamp -i half-small.nrrd -min 0.05 \
 | GLYPH -g sph -gsc 0.006 -o - \
 | unu slice -a 0 -p 0 \
 | unu gamma -g 0.92 \
 | unu quantize -b 8 -min 0 -max 1 -o half-sph.png

tend evalclamp -i half-small.nrrd -min 0.05 \
 | GLYPH -g sqd -gsc 0.0051 -o - \
 | unu slice -a 0 -p 0 \
 | unu gamma -g 0.92 \
 | unu quantize -b 8 -min 0 -max 1 -o half-sqd.png

rm -f emap.nrrd

unu resample -i half-sph.png -s 300 300 -o _half-sph.png
unu resample -i half-sqd.png -s 300 300 -o _half-sqd.png
unu resample -i half-sph.png -s 100 100 -o __half-sph.png
unu resample -i half-sqd.png -s 100 100 -o __half-sqd.png