# My First Volume - 2/5¶

## Geometry¶

We want the paddle shifted 30 cm in z relative to the target (0,0,0):

$detector{"pos"} = "0*cm 0*cm 30*cm";$detector{"rotation"}    = "0*deg 0*deg 0*deg";


The type of geant4 solid is “box”. Since we want to study two versions of it, a short and a long one, its dimensions depend on the variation name. Notice how units are specified:

$detector{"type"} = "Box"; if($configuration{"variation"} eq "short")
{
$detector{"dimensions"} = "2*cm 2*cm 4*cm"; } if($configuration{"variation"} eq "long")
{
$detector{"dimensions"} = "2*cm 2*cm 10*cm"; }  The material of this paddle is a predefined geant4 material: $detector{"material"}    = "G4_GLASS_LEAD";


The color entry is a 6 digit hexadecimal number that represents Red, Green and Blue weights from 0 to 255 each in the form: RRGGBB. Let’s make it blue/greenish:

$detector{"color"} = "339999";  Finally, the volume is set to “visible” (0 would be “invisible”) and the style to “solid” (0 would be “wireframe”): $detector{"visible"}     = 1;
\$detector{"style"}       = 1;


Easy right? target.pl looks even easier, since we can omit position (defaulted at (0, 0, 0), rotation and visibility (defaulted at 1).