The Assembly Hierarchy section contains Assembly
entities (ASSE
) relating to all the parts in the MI model.
There will be one ASSE
for each part.
ASSE
s contain information about details of
any shared parts, and provide transformation matrices
for producing images of shared parts.
For more information on matrices, refer to "General Reference Data"
and "Transformation Matrices" in General Reference Data and to
Appendix A.
The Assembly Hierarchy section specifies the number of parts within the drawing, and the parts structure. For a discussion of parts, refer to ME10 User's Guide.
The ASSE
s entities point to a part definition by using
the part name, and use pointers to other ASSE
s to determine
the parts
structure. The ASSE
also contains pointers to properties, for
example to establish Part Status information.
There can be only one Assembly Hierarchy section in an
MI file, and this section contains all the ASSE
s.
There must be at least one
ASSE
that lies at the top of a tree structure, with
pointers to its subordinate ASSE
s. All pointers to
subordinate ASSE
s are to immediate subordinates
(children, but not grandchildren).
It is possible to have multiple instances of a subpart. This
means that the subpart can be displayed in different positions
and attitudes on the screen. In this case, the parent ASSE
has more than one pointer to the ASSE
corresponding to the
subpart. Different transformation matrices are then applied to
produce different images on the screen. Refer to Example 1 in
Overview of MI, "Overview of MI".
The pointer tree and entity description are given in the following paragraphs.
ASSE
The ASSE
also points to the part definition by using the part
name. This is the only case of a "forwards" pointer in MI. All
other pointers point "backwards" to earlier entries in the MI
file.
ASSE | Entity Type. |
n+ | Entity Sequence Number. |
n+ | Property Count. |
PTR | First Property Pointer. |
: | |
PTR | Last Property Pointer. |
If the number of subordinate ASSE s is 0 , the entity
definition ends here. Otherwise, the following
items, as far as the end-of-entity delimiter, are
repeated for each subordinate ASSE .
| |
n+ | Attribute 1 (Virtual Offset for subordinate ASSE ).
|
n+ | Attribute 2. |
n+ | Attribute 3. |
Attribute 1 is used for the sequence number of the first entity of a virtual part. For an explanation of virtual parts see the section on dimension entities. Attribute 2 and 3 are not used in this revision of MI, but are reserved for future use. | |
n+ | Property Count. |
PTR | First Property Pointer. |
: | |
PTR | Last Property Pointer. |
The property pointers may include a pointer to an
Associated Text Property (ASSP ), and this information is
applied to the part corresponding to the subordinate ASSE .
| |
PTR | Pointer to Subordinated ASSE .
|
9×REAL | Transformation Matrix (3x3) to be applied to the
subordinate ASSE , to obtain a visualization of the contents of
the corresponding part.
|
If the visualization is to remain unchanged, the matrix will be an identity matrix, with all the diagonal elements equal to 1 and the other elements equal to 0. | |
See Appendix A, Transformation Matrices.
All the above items, after the Number of Subordinate
| |
n+ | Unique parts name/number of subparts where PTR points to. |
|~ | End of Entity. |