Note on the Thickness parameter and Boolean operations
Some elements — such as boxes, ellipsoids, orbs, parallelepipeds and trapezoids — have an additional useful parameter inside EDGE (not present in GDML) called thickness. If a shape has a thickness defined (different from 0), then the export of this shape will be done using Boolean operations (a subtraction between the outer element and the inner element). It allows the user to gain time for this kind of operation.
This kind of shape can be very useful during the definition of radiation analysis. The user shall be aware that this thickness value is not a GDML parameter, which means that setting this parameter to a value different from zero will result, in the GDML file, to the corresponding Boolean operation. The little warning sign next to the name of this parameter is present to remind the user of this.
If an EDGE file containing a shape with a defined thickness (different from 0) has been saved and is then loaded again, EDGE will try to reload it correctly as the initial shape with thickness and not as the Boolean operation saved in the file.
