Import Geant4 11.2.0.beta source tree

examples/extended/visualization/standalone/README

@@ -6,34 +6,41 @@
                ------------------------------------------
 
 This example illustrates how one might use the Geant4 Visualization
-System as a "stand alone" graphics library and viewer.  It makes use
-of the "user action" feature of the Geant4 vis manager - for a fuller
-example of the use of this feature see
-examples/extended/visualization/userVisAction.
+System as a "standalone" graphics library and viewer, i.e, without
+the overhead of the run manager and all the actions and physics.
 
-1) Define a G4VUserVisAction that implements a Draw method.  An
-   example is provided - see StandaloneVisAction.hh/cc.
-   StandaloneVisAction::Draw illustrates:
-   a) a simple box;
-   b) a Boolean solid;
-   c) an alternative way of drawing a solid by obtaining the
-      polyhedral representation.
-   The last is included for interest, not as a recommendation.
+It makes use of the "user action" feature of the Geant4 vis manager - for
+a simple example see examples/extended/visualization/userVisAction.  You
+have to encapsulate your drawing in a vis action so that the vis manager
+can call it and re-call it as appropriate.
+
+1) Define a G4VUserVisAction that implements a Draw method.  Two
+   examples are provided:
+   - StandaloneVisAction:
+     - a simple box;
+     - a Boolean solid;
+     - an alternative way of drawing a solid by obtaining the
+       polyhedral representation (included for interest, not as a
+       recommendation).
+   - DrawGeometryVisAction:
+     - Shows how to visualise your geometry alone, i.e., without the
+       run manager and the physics stuff.
       
-2) In the main program, StandaloneVisAction must be instantiated and
-   its pointer registered with the visualization manager. You may
-   optionally specify an extent at this point to assist the viewers to
-   locate the objects.
+2) In the main program, the vis actions must be instantiated and
+   registered with the visualization manager. You may (optionally)
+   specify an extent to assist the viewers to locate the objects.
 
-3) To visualise, use the usual Geant4 vis commands to create a view
-   and scene, then add the vis action to the scene, optionally with an
-   extent - see standalone.mac.
+3) To visualise, you need: 
+   - /vis/scene/add/userAction
+
+4) Use the usual Geant4 vis commands to create a scene
+   and view (including the above command) - see standalone.mac.
 
 Note: The system needs an "extent" in order to point the virtual
-camera and adjust its field of view, etc.  This defines the "standard
+camera and adjust its field of view, etc. This defines the "standard
 view".  You may zoom, etc., from this standard view.  The extent may
 be specified as suggested above or by using /vis/scene/add/extent.
 
 
 John Allison
-27th November 2014
+30th December 2022