Extended data (xdata) is created by AutoLISP. If an entity contains extended
data, it follows the entity's normal definition data. The group codes 1000
through 1071 describe extended data. The following is an example of an entity
containing extended data in DXF format. AutoCAD defines a special block
*Uxx for visually repsentation of CSG enities
Let's take CSG box enity apart and put it in order:
(
(-1 . <Entity name: 600000aa>)
Enitiy name it changes and does stay the same
(0 . "INSERT")
0 - Entity Type Where "INSERT"
means the enity is a block
(8 . "0")
8 - Name of Layer
(5 . "17")
5 - Unique Name of Enity
never to change.
(2 . "*U2")
2 - Not a Unique Name
"*U" means that the block is a CSG enity.
(10 0.0 0.0 0.0)
10
- x 0.0 , y 0.0 , z 0.0 The base point or
insert point
(41 . 1.0)
(42 . 1.0)
(50 . 0.0)
(43 . 1.0)
(70 . 0)
(71 . 0)
(44 . 0.0)
(45 . 0.0)
(210 0.0 0.0 1.0)
210 -
This is default unless extruded.
(-3
("AME_SOL"
(1002 . "{")
1002 -Extended
data control string can be either "{"or "}" These braces enable applications to organize
their data by subdividing the data into lists. The left brace begins a list,
and the right brace terminates the most recent list. Lists can be nested.
(1070 . 1)
(1071 . 1.58946e+006)
(1070 . 1536)
(1070 . 1)
(1010 4.0 5.0
6.0)
(1005 . "0")
(1005 . "18")
(1005 . "0")
(1040 . 0.0)
(1040 . 1.0)
(1070 . 0)
(1000 . "MILD_STEEL")
(1000 . "0")
(1002 .
"}")
1002 -Extended data control string can be either "{"or "}"
)
("AVE_INVOKE"
(1000 . "SOLAVEMESH")
)
)
)
(
(-1 . Entity name: 37b0648) -1 - AutoCad Entity Name (AutoCAD does this Automatically)
(0 ."LINE") 0 - Entity Type
(5 . "89") 69 - Handle name (if handles are turned on)
(8 . "STR") 8 - Name of Layer
(10 9.0 7.9375 0.0) 10 - Start Point of Line
(11 11.1213 10.0588 0.0) 11 - End Point of Line
(67 . 0) Don't worry about this
(100 . "AcDbLine") Don't worry about this SubClass Marker.
(100 . "AcDbEntity") Don't worry about this
(210 0.0 0.0 1.0) Don't worry about this. This is default unless extruded.
)
Extended data for cone
Command: co
Baseplane/Elliptical/<Center point> <0,0,0>:
Diameter/<Radius>: .5
Apex/<Height>: 2
Phase I - Boundary evaluation begins.
1 of 3 of Phase I in process.2 of 3 of Phase I in process.3 of 3 of Phase
I in process.Phase II - Tessellation computation begins.
1 of 2 of Phase II in process.2 of 2 of Phase II in process.Updating the
Advanced Modeling Extension database.
Command: hfg
Select object: It is a Cone!!
(
("cone"
(0.0 -2.44921e-016 -2.0)
(0.5 0.5 2.0)
)
)
Command: !xdata
(
(1002 . "{")
1002 -Extended data control string can be either "{"or "}" These braces enable applications to organize
their data by subdividing the data into lists. The left brace begins a list,
and the right brace terminates the most recent list. Lists can be nested.
(1070 . 1)
1070 A 16-bit integer (signed
or unsigned)
(1071 . 1.69152e+006)
1071 A 32-bit signed (long) integer
(1070 . 1537)
1070 A 16-bit integer (signed or unsigned)
name of primitive cone = 1537
(1070 . 1)
(1010 0.5 0.5 2.0)
(1005 . "0")
(1005 . "31")
(1005 . "0")
(1040 . 0.0)
(1040 . 1.0)
(1070 . 0)
(1000 . "MILD_STEEL")
(1000 . "0")
(1002 . "}")
1002 -Extended data control string can be either "{"or "}"
)