Tree window

This window can only be launched if the STEP file contains either assembly structures (next_assembly_usage_occurrence), or links to externally defined geometry (AP214 external_reference mechanism), or a mixture of both. If this precondition is not met, the Assembly menu will not be present and the assembly window thus cannot be activated.

In the case that a structure is contained, the tree window will initially show the complete structure tree, which is scaled to fit into the window.

Figure 1. Example of a product structure tree

Elements used in the tree display

• Nodes: A node represents either a product_definition or an external document.

  
  Blue nodes represent either product_definitions (= Design_discipline_item_definition, or DDID, in AP214), or product_definition_formations (= Item_versions in AP214). This can be controlled by the buttons to the upper left of the tree window:
  
  If, as shown and as by default, "DDID" is set, a blue node will be created for each product_definition representing a DDID in the STEP file. It will contain three lines of text. The three lines of text contain the hash number and id attribute value of the product, the product_definition_formation, and the product_definition represented by the node.

  If "Item_version" is set, a blue node will be created for each product_definition_formation representing an Item_version in the STEP file. This node will have at least three, but possibly more, lines of text. The first two lines will indicate the product and product_definition_formation instance as in the "DDID" case. The node will then contain a horizontal line and below it, all product_definitions that belong to this product_definition_formation:
  
  In this example there are four product_definitions (DDIDs) belonging to the same product_definition_formation (Item_version).

  Note: In general, most CAD systems will not support multiple views on the same part, therefore there is usually a 1:1 relation between product_defintions and product_definition_formations and the graphs for both cases will be identical. However, PDM systems typically support a 1:n relation here and therefore the graphs may differ considerably.
  Note 2: If either mode produces a trivial graph (single level) it is suppressed and the buttons that allow to switch between modes will not be presented.

  
  Red nodes represent external documents. The first line of text contains: hash number of document_file and the name of the external file (either document source property value, or document.id attribute). The second line of text contains the hash number of the shape_representation that is the external_model representation of the document, and the document format property value if present, otherwise the document_type value.

• Links: A link connects two nodes. In case the nodes are of the same type, a tag is drawn that contains additional information:

  
  A link between two blue nodes carries the hash number of the next_assembly_usage_occurrence, and the hash number of the representation_relationship or mapped_item which defines the link in the STEP file.
  
  If the lower part of the node is left empty, no representation_relationship or mapped_item is present for the next_assembly_usage_occurrence.

  
  A link between external documents carries the hash number of the representation_relationship that links the documents (i.e., shape_representations) involved in the STEP file.

  
  In case a document is linked to a product_definition/product_definition_formation node, no additional information is displayed.

  The link tag's color classifies the transformation involved in the link:

  • 
    If the link is drawn in background color, the child is not positioned with respect to the parent node, or the transformation is the identity transformation.

  • 
    If the link is drawn in green, the child is positioned with respect to the parent node.

  • 
    If the link is drawn in red, the child is positioned with respect to the parent node, and the determinant of the transformation matrix is negative (i.e., a mirroring transformation).

• Actuators:

  
  An actuator represents a sub-tree that is not displayed to allow for a better overview of the tree. When a node gets clicked with the middle button of the mouse, its children will be hidden from the display and represented by an actuator. When an actuator is selected (left mouse button), the children will appear again. The level up to which the children re-appear can be preset using the buttons on the upper righthand side of the tree window:
  
  "Any" will expand the whole subtree represented by an actuator, whereas "One" will only expand the next level of the subtree represented.

Interaction with the tree window

Mouse button	Key	Pointer over...	Action
none	none	node or link	highlight instance in geometry display
left	none	node or link	search for hash number under pointer in text section
		actuator	expand hidden subtree
middle	none	node	hide child nodes, display an actuator
right	none	nothing	scale/move tree so that it's entirely visible
		node, link, actuator	center display around item, with scaling set to 1
middle	ctrl		zoom window according to vertical mouse movement
right	ctrl		move window

Whenever an instance gets marked in the text section, or highlighted in the geometry display, all occurrencies of the instance within the tree window will be drawn in the appropriate color.

In order to close the tree window, select the "Dismiss" button in its upper righthand corner.