ReleaseNotes.md

# v01-07-01

* 2018-05-17 Frank Gaede
   - fix bug in input handling, for details see discussion [#387](https://github.com/AIDASoft/DD4hep/issues/387)
     - exclude leptons with zero lifetime from Geant4

# v01-07

* 2018-03-26 Javier Cervantes Villanueva ([PR#343](https://github.com/AIDASoft/DD4hep/pull/343))
  - Fix bug in calculating eta, introduced in #138 
    - use `magFromXYZ` instead of `radiusFromXYZ` to calculate pseudorapidity

* 2018-03-19 Frank Gaede ([PR#338](https://github.com/AIDASoft/DD4hep/pull/338))
  - Include fixes from Chris Burr for the alignments calculator.
   - Add a small study for the LHCb upgrade defining reasonable detector element conditions for the Velo pixel detector using the DDCond derived condition mechanism.
   - To be done: somehow get an example for this mechanism, which works outside Gaudi.

* 2018-03-23 Markus Frank ([PR#340](https://github.com/AIDASoft/DD4hep/pull/340))
  - Improvement for DDDB - case study to implement real-world detector elements.

* 2018-03-28 Frank Gaede ([PR#345](https://github.com/AIDASoft/DD4hep/pull/345))
  - Remove `DDSurfaces` folder as it was merged in `DDRec`

* 2018-03-28 Frank Gaede ([PR#341](https://github.com/AIDASoft/DD4hep/pull/341))
  - Remove top level `DDSegmentation` folder as it is not needed anymore

# v01-06

* 2018-01-31 Ete Remi ([PR#297](https://github.com/aidasoft/dd4hep/pull/297))
  - Geant4Output2LCIO
     - Switch run header writing order at beginning of run instead of end of run

* 2018-03-15 Marko Petric ([PR#335](https://github.com/aidasoft/dd4hep/pull/335))
  - Deduce CLHEP location from `CLHEP_INCLUDE_DIR` ( Fixes #314 )
  - Add `gSystem.Load('libglapi')` to `testDDPython.py` which failed due to TLS issues on local machine
  - Add Geant4 10.4 to test suite

* 2018-03-14 Markus Frank ([PR#336](https://github.com/aidasoft/dd4hep/pull/336))
  - New shape definitions for CMS
    Generic Polyhedra, ExtrudedPolygon, CutTube, TruncatedTube, PseudoTrap.
  - DDDB: allow to configure the match for the entity resolver.

* 2018-03-13 Daniel Jeans ([PR#333](https://github.com/aidasoft/dd4hep/pull/333))
  - changed utility name from graphicalMaterialScan -> graphicalScan
  - add visualisation of electric and magnetic fields (switched by parameter)
  - change order of x/y/z range parameters for ease of use
  - added parameter for name of output root file

* 2018-03-12 Markus Frank ([PR#334](https://github.com/aidasoft/dd4hep/pull/334))
  - `step_length_max` not propagated to Geant4 for `G4UserLimit` instances.
   - All limits can now be set separately for each particle type (or for all as a catchall situation if the particle type is '*'.
   - Fixes #327

* 2017-11-29 Markus Frank ([PR#271](https://github.com/aidasoft/dd4hep/pull/271))
  - Add `LHeD` example (contribution from Peter Kostka)
  - Fix to support `python3` in `DDG4`
  - Fix issue in Volumes.h for backwards compatibility with gcc version < 5
  - Fix type definition of `XmlChar` to also support Xerces-C 3.2.0
  - Fix `AClick` initialization files in `DDG4` (remove dependency on `libDDSegmentation`)

* 2017-11-29 Marko Petric ([PR#270](https://github.com/aidasoft/dd4hep/pull/270))
  - Fields: Remove pessimizing move and shadow warnings

* 2018-02-06 Ete Remi ([PR#301](https://github.com/aidasoft/dd4hep/pull/301))
  - Geant4Output2LCIO plugin
     - Added run number and event number offset properties. Enable steering of run and event counters from outside
     - Added 3 event parameters properties for int, float and string event parameters

* 2018-02-05 Markus Frank ([PR#304](https://github.com/aidasoft/dd4hep/pull/304))
  - Restructure the files a bit to simplify the use of the `XML` and `JSON` parsers and the spirit utilities in other projects.

* 2018-02-28 Frank Gaede ([PR#323](https://github.com/aidasoft/dd4hep/pull/323))
  - make Geant4InputHandling.cpp compatible w/ gcc49 
       - avoid stringstream move operation
       - fixes #320

* 2018-01-24 Markus Frank ([PR#292](https://github.com/aidasoft/dd4hep/pull/292))
  -  Fix bug in Alignment test:
     - A long standing bug was fixed for the test `t_AlignDet_Telescope_align_new`.
     - It was assumed that the `DetElements` were ordered in memory, which is **not** true (probably due to memory randomization).
     - Moved to path dependent ordering. Test now OK.
     - Closes #282 
  
  -  Removed a Bunch of `rootcling` warnings
     - Apparently `rootcling` now expects a class with the name of the dictionary header file.
     - To satify this some dummy anonymous classes were added.
     - Closes #290

* 2018-01-26 Marko Petric ([PR#296](https://github.com/aidasoft/dd4hep/pull/296))
  -  Check dynamic cast if it was successful

* 2018-01-22 Markus Frank ([PR#289](https://github.com/aidasoft/dd4hep/pull/289))
  - Add possibility to parse `XML` from string
    - Please see  #288 for details.
    - The main interface was not changed. Rather a view to the Detector class supports this functionality.
     - The existing view `dd4hep::DetectorLoad` was enhanced to allow the required functionality:
     ```cpp
      Detector detector = ....;
      /// So here is the actual test: We parse the raw XML string
      DetectorLoad loader(detector);
      loader.processXMLString(buffer,0);
     ```
     - An example was added (`ClientTests/src/XML_InMemory.cpp`, which illustrates the usage).
  
  - Improve DDCond manual
    - Improve that the DDCond manual reflects the source code.
    - The possible plugins provided are not all described. This shall be future work.
  
  - Enable the GDML reader plugin
    - Closes #275

* 2018-03-01 Markus Frank ([PR#325](https://github.com/aidasoft/dd4hep/pull/325))
  - Add dictionaries to `DDRec`. 
    - Consequently add the python interface to access the exported classes.

* 2018-03-01 Ete Remi ([PR#321](https://github.com/aidasoft/dd4hep/pull/321))
  - Geant4InputAction and Geant4EventReader : 
      - Register input action pointer to event reader, enabling the event reader to access the Geant4 context
  - Added new class LCIOEventParameters to handle LCIO input event parameters
  - LCIOFileReader : 
      - Add extension with LCIO input event parameters to Geant4event
  - Geant4Output2LCIO : 
      - Get LCIO event parameters from event extension (if any) and write them to LCIO output event

* 2018-03-01 David Blyth ([PR#317](https://github.com/aidasoft/dd4hep/pull/317))
  - DDCore: added CartesianStrip segmentations

* 2018-03-02 Frank Gaede ([PR#328](https://github.com/aidasoft/dd4hep/pull/328))
  - finalize the python bindings for DDRec:
      - implement StructExtension(DetElement&) and toString() 
      - add DetectorData classes to python 
      - add example `dumpDetectorData.py`
      - closes #306 
  - remove deprecated methods and classes in DDRec
      - resolves #326

* 2018-03-06 Andre Sailer ([PR#331](https://github.com/aidasoft/dd4hep/pull/331))
  - Geant4InputHandling: reject stable particles without lifetime (e.g., initial state electrons), fixes #330

* 2018-03-07 Markus Frank ([PR#329](https://github.com/aidasoft/dd4hep/pull/329))
  - Fixes #324
  - Call `TGeoMixture::ComputeDerivedQuantities()` for ROOT >= 6.12.0 (Resolves #281)
  - Start to address issue: https://github.com/AIDASoft/DD4hep/issues/327

* 2018-03-07 Daniel Jeans ([PR#322](https://github.com/aidasoft/dd4hep/pull/322))
  - correct coded expressions for quadrupole, sextupole and octopole fields.
  - correct expression for octopole field in documentation

* 2018-03-09 Ercan Pilicer ([PR#319](https://github.com/aidasoft/dd4hep/pull/319))
  - Remove unnecessary `import exceptions` from python

* 2017-11-30 Markus Frank ([PR#272](https://github.com/aidasoft/dd4hep/pull/272))
  ### DDG4 enhancements
  - Enable framework support in DDG4. The `Geant4Context` is the main thread specific accessor to the `dd4hep`, `DDG4` and the user framework.
      - The access to the `dd4hep` objects is via the `Geant4Context::detectorDescription()` call,
      - the access to `DDG4` as a whole is supported via `Geant4Context::kernel()` and
      - the access to the user gframework using a specialized implementation of:
      `template <typename T> T& userFramework()  const;`
   
      A user defined implementations must be specialized somewhere in a compilation unit of the user framework, not in a header file. The framework object could host e.g. references for histogramming, logging, data access etc.
    
      This way any experiment/user related data processing framework can exhibit it's essential tools to `DDG4` actions.
    
      A possible specialized implementations would look like the following:
    ```cpp
      struct Gaudi  {
        IMessageSvc*   msg;
        IHistogramSvc* histos;
        ....
      };
      template<> Gaudi& Geant4Context::userFramework<Gaudi>()  const  {
        UserFramework& fw = m_kernel->userFramework();
        if ( fw.first && &typeid(T) == fw.second ) return *(T*)fw.first;
        throw std::runtime_error("No user specified framework context present!");
      }
    ```  
      To access the user framework then use the following call:
      ```cpp
      Gaudi* fw = context->userFramework<Gaudi>();
      ```
      of course after having initialized it:
    ```cpp
      Gaudi * fw = ...;
      GaudiKernel& kernel = ...;
      kernel.setUserFramework(fw);
    ```
  
  - `G4RunManager` is now a plugin. To enable user defined run managers in `DDG4`, the run manager is encapsulated in a `Geant4Action`. See `DDG4/plugins/Geant4RunManagers.cpp` how to implement such plugins. Currently there are to factories implemented: 
     -  `G4RunManager` -> factory invokes the single threaded `G4RunManager`
     -  `G4MTRunManager `-> factory invokes the multi threaded `G4MTRunManager`
  
    The factory names here are identical to the names of the native G4 classes.

* 2017-11-30 Marko Petric ([PR#268](https://github.com/aidasoft/dd4hep/pull/268))
  - Introduce new DD4hep web-site: http://dd4hep.cern.ch/
    - Page is automatically build from [this repo](https://gitlab.cern.ch/CLICdp/DetectorSoftware/DD4hep-website)
  - Restructured `doc` folder and removed not doc related stuff to `etc` 
  - Fixes to Doxygen configuration
    - create reference manual `make reference`
  - Better integration of DD4hep tex documentation and cmake
    - create manuals in PDF format `make pdf` create manuals in HTML format `make html`
    - allow creation of documentation if dependencies are not present
  - extended gitlab runners to automatically build documentation PDF and HTML and also reference manual and publish to web-site, thus ensuring always up to date information.

* 2018-02-14 Markus Frank ([PR#310](https://github.com/aidasoft/dd4hep/pull/310))
  - Fix MC truth problem in DDG4
  - Update of the `XML` reader to simplify externalization

* 2018-02-15 David Blyth ([PR#302](https://github.com/aidasoft/dd4hep/pull/302))
  - Added "NOINSTALL" option to cmake build function dd4hep_add_library

* 2018-02-16 Andre Sailer ([PR#315](https://github.com/aidasoft/dd4hep/pull/315))
  - DDG4::ExtraParticles: particles with too small life time were tagged as stable, now correctly marked unstable
  - DDG4::Geant4InputHandling: pass all particles except strings, quarks and gluons to Geant4 to get completely consistent MCParticle History, fixes #307 
  - DDG4::Geant4PrimaryHandler: add property RejectPDGs
  - DDG4::Geant4InputHandling: print geant4 primary particle chains if VERBOSE

* 2017-11-16 David Blyth ([PR#258](https://github.com/aidasoft/dd4hep/pull/258))
  - Corrected `EcalBarrel` constructor after finding significant layer overlaps
  - Corrected `CylindricalEndcapCalorimeter` factors of 2 in layer/slice thickness
  - Corrected `ForwardDetector` factors of 2 in layer/slice thickness

* 2017-12-05 Marko Petric ([PR#278](https://github.com/aidasoft/dd4hep/pull/278))
  - Remove `DD4HEP_USE_CXX11` and `DD4HEP_USE_CXX14` and use [CMake default way](https://cmake.org/cmake/help/v3.1/variable/CMAKE_CXX_STANDARD.html)`CMAKE_CXX_STANDARD` to define C++ standard

* 2017-12-05 Marko Petric ([PR#277](https://github.com/aidasoft/dd4hep/pull/277))
  - Fix logic for ignoring warnings in dictionary creation
  - Add `-Wno-overlength-strings` to all generated targets

* 2017-12-05 peterkostka ([PR#276](https://github.com/aidasoft/dd4hep/pull/276))
  - Update of LHeD example - overlaps (problem with SubdetectorAssembly)

* 2017-12-01 Markus Frank ([PR#275](https://github.com/aidasoft/dd4hep/pull/275))
  - Add Support to Export and Import GDML Data
    - Allow extorts and imports of partial geometry trees with GDML. **This requires however a future version of ROOT**, since some changes were necessary in the ROOT GDML handlers. The code is commented out for the time being. The plugin implementation is in `DDCore/src/gdml/GdmlPlugin.cpp`
  - Remove print statements from DDG4 scripts
     - Replace prints with calls to the python logging utility. Hopefully this shall give at some point python3 compatibility.
  - Update `G4Stepper` factories
    - Add some missing steppers

* 2017-12-01 Marko Petric ([PR#274](https://github.com/aidasoft/dd4hep/pull/274))
  - Revert `DDG4.py` Geant4 initialization parameters back to values specified in Geant4 (see discussion #266)

# v01-05

* 2017-11-10 Dan Protopopescu ([PR#262](https://github.com/aidaSoft/DD4hep/pull/262))
  - Added createGearForSiD minimal plugin solely for use with LCCalibration

* 2017-11-10 Frank Gaede ([PR#261](https://github.com/aidaSoft/DD4hep/pull/261))
  - add `Geant4::HitData::MonteCarloContrib::length`  (step length) 
  - set in all CalorimeterSDActions
  - write out it LCIO if `Geant4Sensitive::DETAILED_MODE` and LCIO_VERS>v02-10

* 2017-11-10 Whitney Armstrong ([PR#260](https://github.com/aidaSoft/DD4hep/pull/260))
  - added electric and magnetic field functions that return the field value (taking the position as the only argument) directly in `dd4hep::OverlayedField`

# v01-04

* 2017-10-17 Markus Frank ([PR#248](https://github.com/aidasoft/DD4hep/pull/248))
  ### VolumeManager Implementation
  A possibly important bug was fixed for the lookup of top level subdetectors in the `VolumeManager` by volume identifers of (sensitive) volumes. Due to a bug in the de-masking possible wrong top level subdetectors were returned. The default use cases typically do not use this call and hence should not be affected.

* 2017-10-17 Shaojun Lu ([PR#247](https://github.com/aidasoft/DD4hep/pull/247))
  - Fix C++11 pointer error by adding include <memory> for 'unique_ptr' (GCC 4.9).

* 2017-10-13 Marko Petric ([PR#246](https://github.com/aidasoft/DD4hep/pull/246))
  ### DDCMS:
  - Improve the CMS excercise. New examples etc.
  - Support for simulation using DDG4 (at least partially - since not all subdetector volumes are accepted by Geant4).
  
  ### DDG4:
  - Event reader returns `EVENT_READER_EOF` if `EOF` is detected rather than a generic IO error.
  - Add generator status word to the `Geant4Particle` object. Remove the extension mechanism, which is very heavy to just add one integer.
  
  ### General:
   - We need to distinguish the plugins using some namespace mechanism. I started to introduce the namespace separator `"_".` Hence all DD4hep plugins start with `DD4hep_<plugin>`. I hope this does not break everything. If it does, please notify me and we can undo.

* 2017-10-13 Whitney Armstrong ([PR#243](https://github.com/aidasoft/DD4hep/pull/243))
  - Added helper function `getAttrOrDefault` (defined in  `DDCore/include/XML/Helper.h`) 
   This  function `getAttrOrDefault(xml::Element e, xml::XmlChar attr_name, T default_value)` will return the attribute  name,  converted to to type `T` but if it is not found it will return `default_value`. When building new detectors supplying this is useful for supplying default attribute values.

* 2017-10-19 Markus Frank ([PR#249](https://github.com/aidasoft/DD4hep/pull/249))
  * Improve the CMS tracker visualisation
  * Add DDG4 simulation example to DDCMS
  * Add some plugins to add visualisation attributes if required (not for the compact description)

* 2017-11-01 David Blyth ([PR#254](https://github.com/aidasoft/DD4hep/pull/254))
  - DDG4/python/DDG4.py: loadDDG4() changed to not raise exception if libraries are already loaded

* 2017-11-01 David Blyth ([PR#252](https://github.com/aidasoft/DD4hep/pull/252))
  - Added requirement of Python 2 in cmake/FindPYTHON.cmake.  This makes clear the requirement of Python 2, and resolves the issue where CMake tries to build with Python 3 in a system where both exist.

* 2017-11-07 Frank Gaede ([PR#256](https://github.com/aidasoft/DD4hep/pull/256))
  - bug fix in `BitField64::operator[std::string]() `
  - make uses of TString in DocumentHandler.cpp compatible with clang9 (on Mac)

# v01-03

* 2017-10-12 Frank Gaede ([PR#244](https://github.com/AIDASoft/DD4hep/pull/244))
  - allow for unbounded surfaces in DDRec
       - add new property `SurfaceType::Unbounded`
       - if a surface is marked unbounded `Surface::insideBounds()` ignores the volume boundaries (and only checks the distance to the surface)

* 2017-09-19 Whitney Armstrong ([PR#233](https://github.com/AIDASoft/DD4hep/pull/233))
  - Added helper  `CellIDPositionConverter::cellDimensions(const CellID& cell)`

* 2017-10-09 Frank Gaede ([PR#242](https://github.com/AIDASoft/DD4hep/pull/242))
  - improve `BitFieldCoder` class
      - remove heap allocation of BitFieldElements
      - add move constructors for efficient filling of vector

* 2017-09-29 Frank Gaede ([PR#238](https://github.com/AIDASoft/DD4hep/pull/238))
  - add new threadsafe class `BitFieldCoder` as replacement for `BitField64`
  - use as `const` everywhere
  - re-implement `BitField64` using `BitFieldCoder`
    - is thread safe if used locally 
    - can be instantiated from `const BitFieldCoder*`

* 2017-09-18 Markus Frank ([PR#234](https://github.com/AIDASoft/DD4hep/pull/234))
  - Created a new example showing the CMS tracking detector
    - Get CMS going with their evaluation. Added a package DDCMS with the conversion plugins for the silicon trackers and the corresponding conversion mechanism for their `xml` structure.

* 2017-09-18 Frank Gaede ([PR#232](https://github.com/AIDASoft/DD4hep/pull/232))
  - fix reading of stdhep/lcio generator files with generator statuses not in [0,3]
  - add `G4PARTICLE_GEN_BEAM` and `G4PARTICLE_GEN_OTHER` to DDG4
    -  `G4PARTICLE_GEN_BEAM`  is generally agreed to be used for beam particles (HepMC, LCIO)
    -  all other status codes vary from generator to generator and we use OTHER
  - for stdhep or lcio input the true generator status is preserved in the lcio output, regardless of its value
  - create a vertex for every parent-less particle in LCIOEventReader
    - this allows for example to read GuineaPig files ( non-prompt pair particles) or special user created files with non-prompt particles
   - Resolves #101

* 2017-09-20 Markus Frank ([PR#235](https://github.com/AIDASoft/DD4hep/pull/235))
  - A more complete version of the CMS tracker
     - Enhanced the CMS tracker example to be more complete.
     - Stopped at some point to convert all CMS algorithms. Hence, the tracker is not complete, but the remaining work looks to be purely mechanical.

* 2017-10-02 Frank Gaede ([PR#239](https://github.com/AIDASoft/DD4hep/pull/239))
  - add cell sizes to printout of `LayeredCalorimeterData::layer`
      - used in `dumpdetector -d`

* 2017-09-14 Frank Gaede ([PR#231](https://github.com/AIDASoft/DD4hep/pull/231))
  - adapt LCIOEventReader for Pythia8 and Whizard2
    - add all parent-less particles to outgoing vertex
    - fixes #226 and closes #229 
    - also used for stdhep files

* 2017-09-07 Daniel Jeans ([PR#227](https://github.com/AIDASoft/DD4hep/pull/227))
  - Fix calculation of cell position in `MegatileLayerGridXY`
  - previously, returned position was the lower corner of the cell
  - after this bug fix, it's the cell centre

* 2017-10-05 Frank Gaede ([PR#241](https://github.com/AIDASoft/DD4hep/pull/241))
  - remove deprecated and unused classes from DDRec

* 2017-10-05 Frank Gaede ([PR#240](https://github.com/AIDASoft/DD4hep/pull/240))
  - add `dd4hep::rec::FixedPadSizeTPCData.zMinReadout`
       - needed to describe the cathode thickness

* 2017-08-21 Markus Frank ([PR#221](https://github.com/AIDASoft/DD4hep/pull/221))
  - Document several classes in doxygen notation.
     - Aim is that there are (at least) no class headers without docs.
     - See [documentation](http://test-dd4hep.web.cern.ch/test-dd4hep/doxygen/html/annotated.html)

# v01-02                                                                                                                                                                        

* 2017-07-14 Daniel Jeans ([PR#204](https://github.com/AIDAsoft/DD4hep/pull/204))
  - add ncellsX/Y as a "parameter", allowing it to be set in compact description. This change is for easier use in the case of a MultiSegmentation. (Only a uniform segmentation can be defined in this way: for more complex cases, must set by driver.)                                                                                                                                                                                                                                 
  - change from array to std::vector to store ncells information                                                                                                                                                                             

* 2017-07-17 Markus Frank ([PR#206](https://github.com/AIDAsoft/DD4hep/pull/206))
  ## Implement ROOT persistency mechanism for detector descriptions (continuation of AIDASoft/DD4hep#202).
  Object extensions are now persistent.                                                                   
                                                                                                          
  This is however not for free: **it requires a dictionary for the extension itself and it requires a dictionary for the class holding the extension**. These are:
   - `dd4hep::DetElement::DetElementExtension<IFACE,CONCRETE>` for `DetElement` extensions.                                                                       
   - `dd4hep::SimpleExtension<IFACE,CONCRETE>` for simple extension managed by the user framework (user calls explicitly destructor).                             
   - `dd4hep::DeleteExtension<IFACE,CONCRETE>` for simple extension managed by dd4hep (dd4hep calls automatically destructor on hosting object destruction).      
   - `dd4hep::CopyDeleteExtension<IFACE,CONCRETE>`. As above, but these extensions support calling the copy constructor of the embedded object and hence allow to copy also the hosting objects.
                                                                                                                                                                                                
  Please note: to persistify these objects it was necessary to no longer use the type-info of the objects as an identifier, but rather a 64-bit-hash of the raw type-info-name. This relies that this name is identical across platforms. This typically is true for linux, but not enforced by any standard.                                                                                                                                                                             

* 2017-08-11 Andre Sailer ([PR#213](https://github.com/AIDAsoft/DD4hep/pull/213))
  - CMake:: dd4hep_generate_rootmap: use CMAKE_INSTALL_LIBDIR if it is set. If the macro is called from other libraries this variable might be set and should be used for consistency. Fixes #212

* 2017-07-13 Markus Frank ([PR#202](https://github.com/AIDAsoft/DD4hep/pull/202))
  ## Implement ROOT persistency mechanism for detector descriptions              
                                                                                 
  The following commits allow to save and restore Detector objects (ie. the full detector description) to/from ROOT. Most changes affected the usage of void pointers. 
                                                                                                                                                                       
  It is **NOT** possible to:                                                                                                                                           
   * save object extensions. Another usage of void pointers and type-info objects, which both cannot be saved.                                                         
   * save callback objects. Callbacks store in memory pointers to member functions. These depend on the loading of libraries at run-time and hence may differ from application to application.
   * save conditions slices. This shall be a futute extension. There should be no fundamental problem doing so - it was simply not yet done.                                                  
                                                                                                                                                                                              
  In the example area a new slot call "Persistency" was created with various tests:                                                                                                           
   * Save and restore simple conditions                                                                                                                                                       
   * Save and restore the MiniTel detector (`examples/ClientTests/compact/MiniTel.xml`)                                                                                                       
   * Save and restore the CLICSiD detector (`examples/CLICSiD/compact/compact.xml`)                                                                                                           
                                                                                                                                                                                              
  The detector examples also have a set of tests associated to check the validity of the restored information.                                                                                
                                                                                                                                                                                              
  ## Integrate `DDSegmentatation` into `DDCore`                                                                                                                                               
                                                                                                                                                                                              
  As a first step to start the cleanup of `DDSegmentation` the code was integrated into `DDCore`. For backwards compatibility a dummy library `libDDSegmentation.so` is kept, so that client cmake files directly referring `DDSegmentation` still work. **This tough is only a temporary measure and users should remove references to the DDSegmentation library.** Include files can be accessed as before. These are part of the `DDCore` include directory.                          

* 2017-08-15 Yorgos Voutsinas ([PR#216](https://github.com/AIDAsoft/DD4hep/pull/216))
  * Adding variable "nocore" for beam pipe (with default value = false) In case the variable appears in the BP xml file as "true", the BP sections will have no core of beam material, in order that someone might add various BP walls made of different materials while avoiding G4 overlaps. Example of use:                                                                                                                                                                           
  ```xml                                                                                                                                                                                                                                     
  <detector name="BeBeampipe" type="DD4hep_Beampipe_o1_v01" insideTrackingVolume="true" nocore="true" vis="BeamPipeVis">                                                                                                                     
  ```                                                                                                                                                                                                                                        

* 2017-08-15 Jan Strube ([PR#215](https://github.com/AIDAsoft/DD4hep/pull/215))
  - LCIOEventReader: adding parameter for the name of the MCParticle collection: `MCParticleCollectionName`

* 2017-08-14 Markus Frank ([PR#217](https://github.com/AIDAsoft/DD4hep/pull/217))
  ## Enhance ROOT Detector Description Persistency                               
  Conditions slices from the DD4hep conditions store can now be saved to ROOT files ans named objects. Conditions persistency examples are added to the `examples/Conditions` section.
  The examples are derived from the Telescope and CLICSiD example:                                                                                                                    
   - `Conditions_Telescope_root_save`                                                                                                                                                 
   - `Conditions_Telescope_root_load_iov`                                                                                                                                             
   - `Conditions_Telescope_root_load_pool`                                                                                                                                            
   - `Conditions_CLICSiD_root_save_LONGTEST`                                                                                                                                          
   - `Conditions_CLICSiD_root_load_iov_LONGTEST`                                                                                                                                      
   - `Conditions_CLICSiD_root_load_usr_LONGTEST`                                                                                                                                      
   - `Conditions_CLICSiD_root_load_cond_LONGTEST`                                                                                                                                     
                                                                                                                                                                                      
  ## Fix Handle Problem when Accessing Materials from Volumes                                                                                                                         
  A cast problem was not spotted in the last commit, which manifested itself in accessing invalid materials from volumes. This commit resolves #211 , reported by @jhrdinka.          
                                                                                                                                                                                      
  A set of tests checks this behaviour in the ClientTests: `ClientTests_volume_materials_<text>`, where the volume tree is scanned and for all sensitive volumes and access the corresponding `materials/TGeoMedium` entities from the volume object.                                                                                                                                                                                                                                     

* 2017-07-18 Shaojun Lu ([PR#208](https://github.com/AIDAsoft/DD4hep/pull/208))
  - added "#include <memory>" for the smart pointers to DD4hepRootPersistency.cpp

* 2017-07-19 Markus Frank ([PR#209](https://github.com/AIDAsoft/DD4hep/pull/209))
  - Implement `dd4hep::Tube` using `TGeoTubeSeg` (See also Issue AIDASoft/DD4hep#203 for details)

* 2017-07-21 Markus Frank ([PR#210](https://github.com/AIDAsoft/DD4hep/pull/210))
  ## Implement ROOT persistency mechanism for the conditions                     
                                                                                 
  Conditions pools can now be made persistent provided all the dictionaries for the payload objects are provided. A new class `ConditionsRootPersistency` allows to save and re-load conditions pools to/from a ROOT file. Such pools can either be:                                                                                                                                                                                                                                      
   - Simple `ConditionsPool` objects                                                                                                                                                                                                         
   - The entire `IOV` indexed pool set (class `ConditionsIOVPool`) or                                                                                                                                                                        
   - A the pool used by a `ConditionsSlice` (class `UserPool`).
   - A std::vector<Condition> which belong all to the same IOV

  In any case the restoration of the saved conditions is performed through the `ConditionsManager` interface in order to ensure proper management of the added condition objects.

  Some example plugin tasks were added in examples/Conditions:
   - `DD4hep_ConditionExample_save` to save conditions to a ROOT file.
   - `DD4hep_ConditionExample_load` to restore conditions from file.

  Others to come.

  ## Split of dictionary files
  The ROOT dictionary creation in `DDCore` was getting increasingly large. Now the ROOT dictionaries are created in several files, what firstly allows them to be produced in parallel and secondly eases the compilation due to smaller generated file sizes.


# v01-01

* 2017-07-06 Markus Frank ([PR#201](https://github.com/AIDASoft/DD4hep/pull/201))
  ## DDCore: Changes to the VolumeManager interface
  
    Recent descrepancies showed that the call to lookup a placement
    from the volume manager may have an ambiguous meaning:
    It may (as used until now) be the placement of thge closest
    detector element - a functionality used by various tests
    or be the placement of the sensitive volume itself.
    So far, since each sensitive volume in the DD4hep tests
    is represented by a DetElement structure, both
    approaches returned the same placed volume.
  
    Since there is the possibility to have sensitive volumes, which are not
    directly connected to a single DetElement structure, this call was
    split to resolve this ambiguity:
  
    /// Lookup a physical (placed) volume identified by its 64 bit hit ID
    PlacedVolume lookupVolumePlacement(VolumeID volume_id) const;
    /// Lookup a physical (placed) volume of the detector element
    /// containing a volume identified by its 64 bit hit ID
    PlacedVolume lookupDetElementPlacement(VolumeID volume_id) const;

* 2017-07-06 Andre Sailer ([PR#200](https://github.com/AIDASoft/DD4hep/pull/200))
  - Now will give a warning if multiple entities (e.g., constants) of the same name are defined in the XML

# v01-00-01

* 2017-07-04 Frank Gaede ([PR#199](https://github.com/AIDASoft/DD4hep/pull/199))
  - bug fix for VolumeManagerContext::toElement() and VolumeManagerContext::placement() 
        - set flag=true in VolumeManager_Populator::add_entry when 
           a ContextExtension is needed, i.e. sensitive volume is not DetElement's volume
  - fixes problems in CellIDPositionConverter

# v01-00

* 2017-06-22 Marko Petric ([PR#192](https://github.com/AIDASoft/DD4hep/pull/192))
  - Move `AlignDet_Telescope_readback_xml` to later in the pipeline since it depends on the output of `AlignDet_Telescope_write_xml`

* 2017-06-22 Andre Sailer ([PR#191](https://github.com/AIDASoft/DD4hep/pull/191))
  - Surface: fix memory leak of transformation matrix
  - XML::Layering: fix memory leak of contained layers in the object

* 2017-06-23 Andre Sailer ([PR#197](https://github.com/AIDASoft/DD4hep/pull/197))
  - Fix memory leaks for Tube, EllipticalTube and Polyhedron

* 2017-06-23 Andre Sailer ([PR#196](https://github.com/AIDASoft/DD4hep/pull/196))
  - CMake: add `Project( DD4hep )`, needed to get the correct CMAKE_CXX_COMPILER_ID on macs due to CMP0025 (cmake policy)
  - CMake: fix treatment of linker flags, they are now properly set for Linux and Macs to error when undefined functions are encountered at link time
  - CMake: fix elif --> elseif when checking threading libraries

* 2017-06-23 Frank Gaede ([PR#195](https://github.com/AIDASoft/DD4hep/pull/195))
  - fix crash in `dd4hep::rec::Surface` after changes in Handle assignment (PR #193)
  - fix use of deprecated `dd4hep::rec::MaterialManager` c'tor in Surface

* 2017-06-20 Frank Gaede ([PR#185](https://github.com/AIDASoft/DD4hep/pull/185))
  - bug fix in material utilities
       - call `MaterialManager( Volume v)` with `Detector.world().volume()`

* 2017-06-20 Marko Petric ([PR#184](https://github.com/AIDASoft/DD4hep/pull/184))
  - Reinstate the full test-suite on Travis

* 2017-06-20 Markus Frank ([PR#183](https://github.com/AIDASoft/DD4hep/pull/183))
  - Unify header guards in DDCore
  - Add header to steer ignoring warnings of rootcling generated dictionaries.

* 2017-06-20 Frank Gaede ([PR#182](https://github.com/AIDASoft/DD4hep/pull/182))
  - cleanup of namespace `dd4hep::rec`
    - remove obsolete bwd compatibility for `DD4hep::DDRec`
    - re-introduce `[deprecated]` warnings for unmaintained classes in DDRec/API 
    - re-fix deprecated c'tor for `MaterialManager` in material utilities

* 2017-06-20 Markus Frank ([PR#181](https://github.com/AIDASoft/DD4hep/pull/181))
  - Attack many warnings from:
    - `-Wshadow`
    - `-Winclude-hygiene`
    - `-Woverlength-strings` (int cling dictionaries)

* 2017-06-20 Markus Frank ([PR#179](https://github.com/AIDASoft/DD4hep/pull/179))
  - Remove a bunch of shadow warnings and include-hygiene warnings.

* 2017-06-21 Marko Petric ([PR#169](https://github.com/AIDASoft/DD4hep/pull/169))
  - Make boost explicit requirement for DD4hep and drop DD4HEP_USE_BOOST

* 2017-06-21 David Blyth ([PR#168](https://github.com/AIDASoft/DD4hep/pull/168))
  - Added environment helper scripts `thisdd4hep_only.(c)sh` that only set up variables for DD4hep and not for dependencies.

* 2017-06-19 Markus Frank ([PR#178](https://github.com/AIDASoft/DD4hep/pull/178))
  - Update documentation after reorganization of namespaces (put back previous docs).

* 2017-06-19 Markus Frank ([PR#175](https://github.com/AIDASoft/DD4hep/pull/175))
  ## DD4hep namespace reorganization
  
  Re-organize namespaces according to the decisions of the DD4hep developers meeting from 16th June we have decided:
  
  1. all namespaces will be lower case and shorter
      * rename namespace `DD4hep` -> `dd4hep`
      * rename namespace `DD4hep::DDRec` -> `dd4hep::rec`
      * rename namespace `DD4hep::Simulation` -> `dd4hep::sim`
      * rename namespace `XML` -> `xml` and `JSON` -> `json`
      * rename all other namespaces according to this pattern
  2. The namespace `DD4hep::Geometry::` will be incorporated into `dd4hep::`
  3. All utilities will be moved `dd4hep::detail`
  4. `LCDD` will be renamed to `Detector` and current `Detector.h` will be renamed to `DetElement.h`
  8. Examine if `DDSegmentation` can be incorporated into `DDCore` and make it volume aware
      * If this this cannot be achieved in whole place `DDSegmentation` into the right namespace
  
    ## DDParsers
  
    DDParsers are now a separate package. This does not make it yet standalone,
    but it is at the same level as e.g. DDSeqmentation. Any librarian is
    encouraged to externialize it fully.

# v00-24

* 2017-06-08 Markus Frank ([PR#160](https://github.com/AIDASoft/DD4hep/pull/160))
  * Add a new class `AlignmentsNominalMap`, which behaves like a `ConditionsMap` and handles alignment entries. 
  * The `AlignmentsNominalMap` is not a conditions cache per-se. This implementation  behaves like a `conditionsmap`, but it shall not return real conditions to the user, but rather return the default alignment objects (which at the basis are conditions as well) to the user. These alignments are taken from the `DetElement` in question `Alignment DetElement::nominal()`.
  
  * The basic idea is to enable users to write code "as if" there would be conditions present. This is important to ease in the lifetime of the experiment the step from the design phase (where obviously no conditions are taken into account) to a more mature phase, where alignment studies etc. actually are part of the "bread and butter work".
  
  * Added a corresponding example in examples/AlignDet:
  ```
  $>   geoPluginRun -volmgr -destroy -plugin DD4hep_AlignmentExample_nominal \
           -input file:${DD4hep_DIR}/examples/AlignDet/compact/Telescope.xml
  ```
     * Access the DetElement nominal conditions using the `AlignmentNominalMap`.
     Any use of DDCond is inhibited.
       1) We use the generic printer, which during the detector element scan accesses the conditions map.
       2) We use a delta scanner to extract the nominal deltas from the `DetElement`'s nominal alignments
       3) We use a `ConditionsTreeMap` to perform the alignments re-computation.

* 2017-06-08 Markus Frank ([PR#159](https://github.com/AIDASoft/DD4hep/pull/159))
  # Implementation of the decisions made at the Conditions mini-workshop
  
  ## Access mechanisms of DD4hep conditions for utilities
  
  Access to conditions is solely supported using the interface class DDCore/ConditionsMap.
  * All utilities must use this interface.
  * Any concrete implementation using conditions/alignment utilities must implement this interface
  * Basic implementation using STL `map`, `multimap` and `unordered_map` are provided.
  * A special no-op implementation of this interface shall be provided to access "default" alignment conditions. This implementation shall fall-back internally to the `DetElement::nominal()` alignment. 
  Known clients: `VolumeManager` (hence: DDG4, DDRec, etc.)
  
  Though this sounds like a trivial change, the consequences concern the entire conditions
  and alignment handling. This interface decouples entirely the core part of DD4hep
  from the conditions cache handling and the alignment handling.
  
  Based on this interface most utilities used to handle conditions, detectors scans
  to visit `DetElement` related condition sets, alignment and conditions printers etc.
  
  For details, please see:
  ```
  DDCore/include/DD4hep/AlignmentsPrinter.h
  DDCore/include/DD4hep/AlignmentsProcessor.h
  DDCore/include/DD4hep/ConditionsPrinter.h
  DDCore/include/DD4hep/ConditionsProcessor.h
  DDCore/include/DD4hep/DetectorProcessor.h
  ```
  
  ## Naming conventions for detector conditions
  
  * Condition are logically attached to DetElements
     * Condition names are: `DetElement.path()+"#"+condition-name`
         Example: `/world/LHCb/DownstreamRegion/Muon/M5/M5ASide/R3ASide/Cham046#alignment`
  
  * Condition keys are a `int64` compound of two `int32`:
  ```cpp
     union {
       int64 key;
       struct {
         int32 item_key;
         int32 det_key;     // Needs to be the high word to have a properly ordered map
       } values;
     };
     det_key  = hash32(DetElement.path())
     item_key = hash32(condition-name)
  ```
     **Condition keys must be unique throughout the detector description.**
  
  * Alignment conditions naming conventions:
    * Alignment-delta conditions are called `alignment_delta`.
    * Fully qualified alignment conditions are called `alignment`.
     DD4hep provided alignment utilities rely on this convention.
  
  * Other conditions can be named freely.
  
  ## Important Notice
  The **Alignment conditions naming conventions** are already used by several utilities involving alignments. If you plan to use these, do not freely ignore these recommendations. When the naming conventions are ignored, these utilities shall not work.
  
  ## Updates to DDCond
  DDCond implements a working conditions cache following the design criteria sketched above. The `conditionsSlice` object implements (though by forwarding to the `ConditionsUserPool`) a `ConditionsMap` interface.
  
  The `DD4hep_ConditionsMapUserPool` plugin implements in a very efficient way this interface using an ordered map. Using the above described key definition, this implementation allows very efficient scans of conditions/alignments etc. of individual detector elements, since conditions which belong to the same detector element are contiguous.
  
  ## Alignment handling/computations
  Using the conditions maps, the computation of (mis-)alignment data from deltas
  is no longer bound to the conditions mechanisms.
  
  A special utility called `AlignmentsCalculator` is put in place (see `DDCore/include/DD4hep/AlignmentsCalculator.h`) to facilitate the computation of a coherent set of alignments given a set of delta-parameters. This mechanism is much simpler, easier to understand and far less code intensive than the previously designed callback mechanism where alignments are obtained using conditions derivation.
  
  ## Update of the existing examples
  
  The example sets in DDDB, `examples/Conditions, examples/AlignDet`, `examples/DDDB` were updated according to the changed mechanism of accessing conditions. Here we can see the real benefits of the new approach: keeping same functionality, the examples became way off simpler. Simply count the number of lines of code.

* 2017-06-17 Marko Petric ([PR#170](https://github.com/AIDASoft/DD4hep/pull/170))
  - Add clang flag to warn about using namespace directive in global context in header

* 2017-06-17 Frank Gaede ([PR#167](https://github.com/AIDASoft/DD4hep/pull/167))
  - renamed the namespace DD4hep::DDRec to dd4hep::rec (see #166)
         - provide backward compatibility to outside world for now
  - moved the interfaces in namespace DDSurfaces to dd4hep::rec
         - provide backward compatibility to outside world for now

* 2017-06-15 Frank Gaede ([PR#165](https://github.com/AIDASoft/DD4hep/pull/165))
  - started to cleanup DDRec
        - don't use  LCDD::getInstance() in SurfaceManager and SurfaceHelper
        -  deprecate unused(?) classes in DDRec/API and DDRec/Extensions
        -  deprecate MaterialManager() using LCDD::getInstance()

# v00-23

* 2017-05-12 Marko Petric ([PR#152](https://github.com/aidasoft/DD4hep/pull/152))
  - Update CI to GCC 7.1 and LLVM 4.0 and include Geant4 10.3

* 2017-05-22 Frank Gaede ([PR#154](https://github.com/aidasoft/DD4hep/pull/154))
  - protect against NANs in Guineapig pairs files in Geant4EventReaderGuineaPig
  - make INFO printout more consistent  with dd4hep style

* 2017-06-07 Frank Gaede ([PR#157](https://github.com/aidasoft/DD4hep/pull/157))
  -  bug fix in test_cellid_position_converter
       - with this no tests for position from cellID lookup should fail
  - re-implement ```CellIDPositionConverter::cellID(pos)```

* 2017-06-08 Marko Petric ([PR#156](https://github.com/aidasoft/DD4hep/pull/156))
  - Mark all fallthroughs in case statements with attributes to suppress warning

* 2017-06-01 Frank Gaede ([PR#155](https://github.com/aidasoft/DD4hep/pull/155))
  - add new class rec::CellIDPositionConverter
        - replaces rec::IDDecoder
        - implement positionNominal(CellID id) and cellID(position)
       - prepare for using alignment map by separating transforms to DetElement and daughter volume
       - do not use deprecated methods/members in VolumeManager
  - add test_cellid_position_converter.cpp
  - add VolumeManagerContext::toElement
       - transform from sensitive volume to next DetElement

# v00-22

* 2017-04-28 Markus Frank ([PR#148](https://github.com/aidasoft/DD4hep/pull/148))
  Improvements to the compact xml processing
  ===========================================
  
  Elements may now be specified within compact in 2 ways:
  1) old way: create an effective element:
  `    <element Z="4" formula="Be" name="Be" >`
  `      <atom type="A" unit="g/mol" value="9.01218" />`
  `    </element>`
  
  2) create element by defining an isotope mixture:
  `    <isotope name="C12" Z="6" N="12"/>`
  `      <atom unit="g/mole" value="xxxx"/>`
  `    </isotope>`
  `.....`
  `   <element name="C">`
  `     <fraction n="0.9893" ref="C12"/>`
  `     <fraction n="0.0107" ref="C13"/>`
  `   </element>`
  
  Improved debugging of compact xml conversions
  The following tags allow to enable increased prinout depending on additional tags in the compact file:
  `    <debug>`
  `      <type name="isotopes"     value="1"/>`
  `      <type name="elements"     value="1"/>`
  `      <type name="materials"    value="0"/>`
  `      <type name="visattr"      value="0"/>`
  `      <type name="regions"      value="0"/>`
  `      <type name="readout"      value="0"/>`
  `      <type name="limits"       value="0"/>`
  `      <type name="segmentation" value="0"/>`
  `    </debug>`
  
  Disable the ROOT TGeo element table from the compact xml. 
  Note: ALL elements must then be specified in the XML material database.
  `    <geometry>`
  `      <clear name="elements"/>`
  `    </geometry>`
  
  By default compact accepts exactly one input file (others may be included therein).
  In order to process iteratively multiple input files, the opening and the closing of the
  geometry steering tags may be added to the compact description. This example 
  gives the default behaviour:
  `    <geometry open="true" close="true"/>`
  
  Please note: per compact file exactly ONE geometry tag is allowed.
  
  
  Debugging the DDG4 geometry conversion mechanism
  =============================================
  New boolean properties of the Geant4DetectorGeometryConstruction object,
  which result in debugging printouts (defaults are OFF):
    DebugMaterials
    DebugElements
    DebugShapes
    DebugVolumes
    DebugPlacements
    DebugRegions
    PrintPlacements
    PrintSensitives

* 2017-04-28 Ben Couturier ([PR#146](https://github.com/aidasoft/DD4hep/pull/146))
  * Trivial fix for the DDDB converter to create paramphysvol3D volumes, which are otherwise ignored.

* 2017-04-20 Andre Sailer ([PR#145](https://github.com/aidasoft/DD4hep/pull/145))
  - LCIOOutput: Add setting of ProducedBySecondary bit for SimTrackerHits if the hit is produced by a particle that is not stored in the MCParticle collection, needs lcio 2.8

* 2017-05-05 Andre Sailer ([PR#150](https://github.com/aidasoft/DD4hep/pull/150))
  - Always create dd4hepConfigVersion.cmake in CMAKE_INSTALL_PREFIX and cmake folder
  - Create DD4hepConfig.cmake also in cmake folder
  - renamed Cmake Macro GENERATE_PACKAGE_CONFIGURATION_FILES to DD4HEP_GENERATE_PACKAGE_CONFIGURATION_FILES so it does not clash with the macro of the same name in ilcutil/cmakemodules

* 2017-05-07 Andre Sailer ([PR#151](https://github.com/aidasoft/DD4hep/pull/151))
  - Use cmake to create Version.h file to contain dd4hep version information and macros
  - Change the way dd4hep package version is defined and set standard cmake variables for this purpose

# v00-21

* 2017-04-03 Marko Petric ([PR#142](https://github.com/AIDASoft/DD4hep/pull/142))
  - Update to the CI system:
    - Install directly cvmfs on base system, which removes the need for the parrot connector 
    - Replace CernVM docker with plain docker
    - This reduces the build run time from 50 min to 25 min

* 2017-03-27 Shaojun Lu ([PR#134](https://github.com/AIDASoft/DD4hep/pull/134))
  - Set verbose true for G4EmSaturation to printout Birks coefficient.

* 2017-03-29 Frank Gaede ([PR#139](https://github.com/AIDASoft/DD4hep/pull/139))
  - add a utility to dump the B-field for a given Volume
          - usage: dumpBfield compact.xml x y z dx dy dz [in cm]  
          - will dump the B-field in volume [-x:x,-y:y,-z,z] with steps [dx,dy,dz]

* 2017-03-29 Joschka Lingemann ([PR#138](https://github.com/AIDASoft/DD4hep/pull/138))
  - Direct implementation that calculates eta from cartesian coordinates
  - Fix: Add registration of Phi-Eta segmentation

* 2017-03-29 Joschka Lingemann ([PR#137](https://github.com/AIDASoft/DD4hep/pull/137))
  - Adding GridRPhiEta a segmentation of equidistant size in R, Phi and Pseudorapidity
  - Adding GridPhiEta a segmentation of equidistant size in Phi and Pseudorapidity

* 2017-03-28 Markus Frank ([PR#135](https://github.com/AIDASoft/DD4hep/pull/135))
  - Accidentally the Segmentations of Joschka were added in the wrong place of the hierarchy.
     I removed them. He will later add them to the proper location.
  - Some C++ warnings concerning the C++11 standard were also fixed.

* 2017-03-24 Yorgos Voutsinas ([PR#132](https://github.com/AIDASoft/DD4hep/pull/132))
  - modifying the LayeredCalorimeterData struct in order to cope with conical shaped calorimeters

* 2017-03-31 Markus Frank ([PR#143](https://github.com/AIDASoft/DD4hep/pull/143))
  - Add new test for multi segment multi collections segmentations using a calorimeter endcap.
     See also: https://github.com/AIDASoft/DD4hep/issues/141, which is still unresolved,
     but seems not to be directly related to the Monte-Carlo truth handling.
  - Side effect: add Geant4EventActions to dump hits and particles
  - Fix a linker problem for unicode tags.

* 2017-03-31 Frank Gaede ([PR#140](https://github.com/AIDASoft/DD4hep/pull/140))
  - clarify documentation for CartesianField and implementations
  - make clear that  void fieldComponents() has to add
     the new field to the given field vector

* Marko Petric 2017-03-23 
  - Convert Release notes to markdown
  - Add some text about WIP and issue tracking
  - Add CONTRIBUTING.md and PULL_REQUEST_TEMPLATE

* Markus Frank 2017-03-17
 
 - Add a new input type by parsing JSON files. The basic json interpreter
    is present and offers essentially the same interface as the XML persers.
    The integration to the compact dialect however is not yet done.
    It should become however a valid alternative to parsing XML files
    with a small maintenance overhead, since the enhancement implementation
    present in XMLDimesion.h, XMLDetector.h and XMLChildValue.h is shared
    and instantiated for both.

* Markus Frank 2017-03-10
 
 - New round to kill coverity deficiencies.
 - Add exception try-catch clauses around various main programs in UtilityApps
    See UtilityApps/src/main.h for details.

* Markus Frank 2017-03-09
 
 - Fix issue with long volume ids exceeding 32 bits.
    Test added in examples/ClientTests
 - Fix volume manager id identical placed volumes are used in different places of the hierarchy.
    Test added in examples/ClientTests
 - Remove various svn left-overs (ID$ strings etc.)


* Frank Gaede 2017-02-10
 
  - allow event readers to create more than one vertex per event
     this should be possible as most generator formats allow to specify
     more than one event vertex 
  - changed signature of Geant4EventReader::readParticles(int,Vertex*, Particles&)
        to Geant4EventReader::readParticles(int,Vertices&, Particles& )
  - implement in LCIOEventReader, Geant4EventReaderHepEvt and Geant4EventReaderHepMC
  - for now still one vertex only is created using the first final state particle
        for HepEvt and LCIO

# v00-20

* Frank Gaede 2017-01-13 
- fix computation of radiation and interaction lengths
- require the density to be specified in the materials xml file
 
* Frank Gaede 2017-01-04 
- adopt numbers in test_surface.cc to elements.xml
- use elements.xml generated with plugin in DDTest
-  add ROOT version to dumped element table

* Frank Gaede 2016-12-22 
- fix test_surfaces by adapting to elements.xml
- fix test_units by including elements.xml
 
* Markus Frank 2016-12-21 
- Add plugin to dump the default ROOT element table
 
* Markus Frank 2016-12-20 
- Remove obsolete build flags
 
* Markus Frank 2016-12-19 
- Add Multi-threading conditions example
 
* Andre Sailer 2016-12-16 
- Add drivers for Beampipe, Mask and Solenoid from lcgeo, changed name to dd4hep_*
 
* Rosa Simonielo, Frank Gaede 2016-12-15 
- add new struct rec::NeighbourSurfacesStruct defined for neighbouring surfaces
 
* Frank Gaede 2016-12-14 
- fix library pathes in env scripts for macos
- use DD4HEP_LIBRARY_PATH and full lib path on mac
- apply rpath compiler settings to GaudiPluginService
- make compatible w/ Geant4 10.3
 
* Marko Petric 2016-12-13 
- Fix compiler flag handling
 
* Daniel Jeans 2016-12-08 
- add utility graphicalMaterialScan
 
* Markus Frank 2016-12-07 
- Fix compiler error on MacOSX gcc 4.9
 
* Marko Petric 2016-12-07 
- Remove few tests from Travis
- move flag to CMAKE_SHARED_LINKER_FLAGS
- Remove the dynamic lookup on runtime for libs on mac
 
* Markus Frank 2016-12-05 
- First version of conditions and alignments
 
* Andre Sailer 2016-12-06 
- DDTest: fix location to install DDtest header files
- Remove minimum required cmake version from DD4hepBuild, this interferes with other packages depending on dd4hep
 
* Marko Petric 2016-12-02 
- Fix missing CLHEP in thisdd4hep.sh
- Clean up FindPYTHON.cmake file
- Change gaudi auto_ptr to unique_ptr since the auto is deprecated
- Fix initAClick
 
* Marko Petric 2016-11-29 
- Fix rpath issues on mac with python
- Add custom DynamicPath on mac when loading python libs
- Add function to set the DD4HEP_LIBRARY_PATH
 
* Marko Petric 2016-11-28 
- Update all minimum CMake versions
- Fix gitlab builds
- Rename MakeRootMap to MakeGaudiMap for consistency
- Remove ROOT5 things and make approprite fixed to the usage of ROOTConfig.cmake
 Remove FindROOT.cmake and use from now on ROOTConfig.cmake
 
 
* Markus Frank 2016-11-30 
- New version of conditions handling
 
* Andre Sailer 2016-11-25 
- Fix ProductionCut conversion in Geant4Converter.cpp: cut is a range
 
* Markus Frank 2016-11-24 
- Fix linker errors on MAC
- Remove compiler warnings on MACOSX
- First fixes to version of alignment constant processing also remove where visited the $ statements in the files.
They are useless, since git does not support them. Fixed some tests, which no longer properly worked in
the conditions area.
- First usable version of alignment constant processing
 
 
* Markus Frank 2016-11-16 
- Try to improve efficiency using C++11 default operations
 
* Markus Frank 2016-11-10 
- Simplify opaque data mappings for conditions
 
# v00-19
* 2016-11-17 D.Jeans
- rewritten MegatileLayerGrid class 
  - not backward compatible 

* M.Petric:
- improved Travis CI configuration 
- remove some tests from CI

# v00-18

* 2016-11-09 F.Gaede
- updated rec::LayeredCalorimeterData::Layer:
  - remove deprecated thickness 
  - add phi0  
- add copy assignement to rec::MaterialData

* 2016-11-08 M.Frank
- Improve conditions handling. Started to implement using simple telescope
  detector from C.Burr.
- Add variable DD4HEP_LIBRARY_PATH to be used on MacOSX El Capitane
  to overcome DYLD_LIBRARY_PATH protection issues.
- Fix to copy with negative(rebased) IDDDescriptor fields
  (affects IDDDescriptor and VolumeManager).
  2 New tests:
  - ClientTests/Bitfield_SidesTest.xml to test readout string:
    system:8,barrel:-2
  - ClientTests/Bitfield_SidesTest2.xml to test readout string:
    system:16,barrel:16:-5
    
* 2016-10-18 M.Frank
-  Due to pressure of the FCC folks, I tried to implement a more dd4hep like implementation of the
  the segmentation objects. For testing only CartesianGridXY. If this mechanism works,