class TEveProjectionManager: public TEveElementList, public TAttBBox

 Constructor.

 Destructor.
 Destroys also dependent elements.

 Add el as dependent element.

 Remove el as dependent element.

 Updates name to have consitent information with prjection.

 Set projection type and distortion.

 Set projection center and rebuild projected scene.

 React to element being pasted or dnd-ed.
 Return true if redraw is needed (virtual method).

 Returns true if element el should be imported.

 Behaviour depends on the value of the fImportEmpty member:
   false - el or any of its children must be projectable (default);
   true  - always import.

 Update dependent elements' vounding box and mark scenes
 cointaining element root or its children as requiring a repaint.

 If el is TEveProjectable add projected instance else add plain
 TEveElementList to parent. Call the same function on el's
 children.

 Returns the projected replica of el. Can be 0, if el and none of
 its children are projectable.

 Recursively import elements and apply projection to the newly
 imported objects.

 If ext_list is not 0 the new element is also added to the list.
 This simplifies construction of complex views where projected
 elements are distributed into several scenes for optimization of
 updates and rendering.

 Returns the projected replica of el. Can be 0, if el and none of
 its children are projectable.

 Project el (via TEveProjected::UpdateProjection()) and recurse
 through el's children.
 Bounding-box is updated along the recursion.

 Project all children recursively, update bounding-box and notify
 TEveManger about the scenes that have been changed.

 Virtual from TAttBBox; fill bounding-box information.

 The bounding-box information is kept coherent during addition of
 projected elements and projection parameter updates. This is
 called only in case the manager has not been populated at all.