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.
