The TLcyLspCameraLinkAddOn comes with four tracking cameras by default. you can override these, or add your custom set of tracking cameras.

To add a custom tracking camera:

  1. Add a custom ALcyCameraLinker. To minimize the effort to provide a custom camera, two abstract subclasses ALcyLspCameraLinker2D and ALcyLspCameraLinker3D are available. They both implement some common code. A concrete implementation of one of those linkers is used to create a tracking camera constraint. You create such a constraint based on a ALspTrackingPointProvider, for example:

    protected ALspCameraConstraint<TLspViewXYZWorldTransformation3D> createCameraConstraint(ALspTrackingPointProvider aTrackingPointProvider, ILspView aView) {
      TLspLookFromTrackingCameraConstraint3D constraint = new TLspLookFromTrackingCameraConstraint3D(false);
      return constraint;
  2. Add a custom ALcyCameraLinkerFactory. This factory must be able to produce one or more custom camera linkers. It can create these linkers based on a type, which is a String value denoting which kind of tracking camera is requested.

    public boolean canCreateCameraLinker(ILcyGenericMapComponent<? extends ILcdView, ? extends ILcdLayer> aMapComponent,
                                         String aType,
                                         List<Object> aObjects,
                                         List<ILcdModel> aModels) {
      return aMapComponent instanceof ILcyLspMapComponent &&
  3. Add a custom add-on. This add-on, possible an extension of TLcyLspCameraLinkAddOn, must make sure that the custom factory is plugged-in.

    public void plugInto(final ILcyLucyEnv aLucyEnv) {
      //add a custom camera linker factory
      fLinkerFactory = new FreeViewLinkerFactory();
      new TLcyCompositeCameraLinkerFactory(aLucyEnv).add(fLinkerFactory);
    public void unplugFrom(ILcyLucyEnv aLucyEnv) {
      new TLcyCompositeCameraLinkerFactory(aLucyEnv).remove(fLinkerFactory);

    Note that if several plugged-in factories provide cameras of the same type, it is the factory plugged in with the highest priority that takes precedence.

  4. Add a custom version of the TLcyLspCameraLinkAddOn's configuration file. This configuration file must contain two major elements:

    • A list of supported camera linker types. The list adheres to these rules:

      • If a factory for a certain type is plugged into the Lucy back-end, but is not part of this list, it will not be taken into account.

      • If this list contains a type for which no factory is available, it will not be taken into account.

      • If this list contains a type for which a factory is plugged in, the add-on will pick it up.

    • A configuration for each active settable matching a custom camera linker type. If no such configuration exists, the camera linker type will not be supported.

Refer to the add-on configuration file for an example of how custom camera types can be configured.

If all these elements are added, the add-on will detect the custom camera linker and will make sure to provide it in the same way as it provides the default camera linkers.