The order of elements - overlapping effects
|Within the Element Browser window click New
with the mouse.
||A new, empty element will be created and appended to the
list of elements.
The Element Editor displays properties of the new element.
It is an EmptyBox with zeroed dimensions (elements of zeroed dimensions have
no effect within the model)
|Following the earlier description enter following data
within Element Editor for the new element:
- X1: 2, X2: 8
- Y1: 2, Y2: 8
- Z1: 2, Z2: 8
- Type: SpaceBox
- Surface name: Interior surface
- Alpha: 10
- Space name: Interior space
and confirm the entry with the TAB key.
|The new element is enclosed by other elements.
Due to the fact being the last element in the list it overlaps all other
|Within the Element3D window switch the
visualization from Solid to Wireframe by turning the switch
||The wire frame representation within the 3D view allows us
to see selected elements not being covered (obscured) by surfaces shown for
|Within Element Browser click onto various elements
and observe the changes to the selection display in graphical windows.
|Within Element Browser click onto the last element –
it shall be the SpaceBox of the „Interior space" – to select
|Within the Element Browser click several times onto
the button Relegate - until the SpaceBox of the interior space
has moved to the Front of the List.
||While changing the order of elements please observe the
effects of overlapping within graphical views which significantly change
being dependant on current sequence.
|Reorder elements to receive following final sequence:
- Exterior space
- Interior space
to create overlapping effect resembling the modelled construction by
using Promote/Relegate command from the Element Browser.
|The element "Exterior space" encloses the rest, but it is
overlapped (hollowed) by element following it in the list.
Similarly the material element is hollowed by the interior space box.
Why is overlapping/hollowing of elements done dynamically? Where is the
Many CAD application provide a static hollowing function (i.e. you select an
element or a group of 3D objects and the application to gouge through them).
Such hollowing operation result in extremely large number of oddments, normally
much higher then the original number of elements.
At the same time the original structure gets lost after such operation If
the user decide, that the operation had undesired effect he can either repeat
the data entry or must undo the whole operation.
To compensate on that tree element structures are used often – each element,
after being hollowed by other elements, brakes into a new branch holding all
resulting oddments. As a result of many such operations a very deep tree
structure is created which is very difficult to undo and, with very complex
models, cannot be managed without additional, extensive and potentially very
For the both reasons (unmanageable complexity at each further step, high
learning costs, error-prone programming effort) we have decided to keep things
simple within a simple, linear list and use the order of the list for dynamic
hollowing providing same result at much less learning effort.
Return to Tutorial Selection...