How to use the phgeom ROOT demo
- The project
This is intended as a tutorial showing various tools we
may use in PHOBOS experiment control and interactive
event display, information about individual detectors,
tracking etc.
More details are in the phgeom
introduction .
- Set up
Unpack the download, which will make and fill a directory
/phgeom. You must have ROOT accessible from the
phgeom directory, with ROOTSYS defined as an environment
variable. All the .C and .html files in phgeom/ must be
present for full HELP function; you must define an
environment variable BROWSER containing the pathname of
your web browser e.g. C:\Netscape\program\Netscape.exe.
- Start
Execute phgeom.C from ROOT command line, or root
phgeom.c, etc. phgeom.C will in turn load the other .C
files including the moderately large phobos.C containing
a ROOT translation of the UGCDATA geometry.
- The red buttons
These draw the named silicon subsystems, adding to the
view (which may be cleared with the white
"Clear" button). These appear in a 3-dimension
view rotatable with a left mouse drag.
- 3D View
The pulldown menu "View" bottom item invokes an
OpenGL view. This may be rendered, enlarged, and
oriented at will but does not give object attributes on a
right mouse click (which we'll need). Try "t",
"w", "r" key effects as well as the
orienting keys; press escape or some other nonfunctioning
key to get a menu.
- The blue, green, aqua and purple buttons
The purple puts in the TOF scintillators, which makes the
other items small in a view. The other buttons show
surrounding supports etc. and may (esp. with the magnet)
make the computer response slow because of the large
number of lines.
- The little 3-color button
This cycles the screen through the initial dark green
(easy on eyes), black (dramatic) and white (best for
printing)
.
- The little red button to its right
This will produce an interesting effect in W95 if the
multimedia files are in the "usual" place.
Sorry, not in UNIX. Longer messages of this sort may be
useful during owl shifts.
.
- The little purple button
This toggle doubles the canvas scale, which puts the
rotator drag box partly outside the picture but gives 2x
magnification.
- The little green button
This toggle makes the x, y and z scale equal so the
object is in "natural" proportions instead of
filling the rotator box. It is not understood why the
objects are not centered in the W95 version, but are
centered in UNIX.
- The remaining buttons
"Clear" resets all phobos.C nodes to invisible
so the canvas is empty. "ROOT Help" looks for a
local /RootHtmlDoc/Welcome.html mirror of root.cern.ch
and if it does not find one, gets the ROOT help
information from Switzerland instead and displays it with
your browser. "Exit" exits ROOT. Finally, HELP
brings up another canvas with six more buttons, including
invoking this page.