AutoCAD VB.net Programming with DXFCODEs

Over the last couple of weeks I've been working with the code for the January 2011 release of DrawOrder by Layer for AutoCAD on the Autodesk Labs Plugin of the month page which can be found here. The code uses a selection filter via the DXFCODE protocol to find the layer names matching the strings in the list generated from the block table record. I am currently revising this command to add some additional items and will post it once it is complete. Here is what the code looks like to select objects on the selected layer:

For Each lay As String In revLst
Dim psr As PromptSelectionResult
Dim tvs(0) As TypedValue
tvs(0) = New TypedValue(DxfCode.LayerName, lay)
Dim sf As New SelectionFilter(tvs)
psr = ed.SelectAll(sf)
If psr.Value IsNot Nothing Then
dot.MoveToTop(New ObjectIdCollection(psr.Value.GetObjectIds))
End If
pm.MeterProgress()
System.Windows.Forms.Application.DoEvents()
Next

While doing this I have been looking through the DXFCODE format codes in VB.net and have been trying to find a list of what these all do and what they are for. I found a pretty good list here, also displayed below in relation to the {}Autodesk.AutoCAD.DatabaseServices namespace. Note that these are in order by the group code and not alphabetical.

DXFCODE Group Names, Codes, and Descriptions

Group Name	Group Code	Description
Invalid	-9999
XDictionary	-6
PReactors	-5	APP: persistent reactor chain
Operator	-4	APP: conditional operator (used only with ssget)
FirstEntityId, XDataStart	-3	APP: extended data (XDATA) sentinel (fixed)
Header	-2	APP: entity name reference (fixed)
End	-1	APP: entity name. The name changes each time a drawing is opened. It is never saved (fixed)
Start	0	Text string indicating the entity type (fixed)
Text, XRefPath	1	Primary text value for an entity
AttributeTag, BlockName, MlineStyleName, ShapeName, SymbolTableName, SymbolTableRecordName	2	Name (attribute tag, block name, and so on)
AttributePrompt, CLShapeName, Description, DimensionAlternativePrefixSuffix, DimPostString, DimStyleName, LinetypeProse, SymbolTableRecordComments, TextBigFontFile, TextFontFile	3-4	Other text or name values
DimensionBlock, Handle	5	Entity handle; text string of up to 16 hexadecimal digits (fixed)
DimBlk1, LinetypeName	6	Linetype name (fixed)
DimBlk2, TextStyleName	7	Text style name (fixed)
LayerName	8	Layer name (fixed)
CLShapeText	9	DXF: variable name identifier (used only in HEADER section of the DXF file)
XCoordinate	10	Primary point; this is the start point of a line or text entity, center of a circle, and so on DXF: X value of the primary point (followed by Y and Z value codes 20 and 30 APP: 3D point (list of three reals)
YCoordinate	20	DXF: Y values of the primary point
ZCoordinate	30	DXF: Z values of the primary point
Elevation	38	DXF: entity's elevation if nonzero
Thickness	39	Entity's thickness if nonzero (fixed)
PixelScale, Real, ShapeScale, ShapeXOffset, ShapeYOffset, TxtSize, TxtStylePSize, TxtStyleXScale, ViewBackClip, ViewFrontClip, ViewHeight, ViewLensLength, ViewportAspect, ViewportHeight,ViewWidth,	40-48	Floating-point values (text height, scale factors, and so on)
LinetypeScale	48	Linetype scale; floating-point scalar value; default value is defined for all entity types
DashLength, LinetypeElement, MlineOffset	49	Repeated floating-point value. Multiple 49 groups may appear in one entity for variable-length tables (such as the dash lengths in the LTYPE table). A 7x group always appears before the first 49 group to specify the table length
Angle, ViewportSnapAngle, ViewportTwist	50-58	Angles (output in degrees to DXF files and radians through AutoLISP and ObjectARX applications)
Visibility	60	Entity visibility; integer value; absence or 0 indicates visibility; 1 indicates invisibility
LayerLinetype	61	Layer Linetype
Color	62	Color number (fixed)
HasSubentities	66	"Entities follow" flag (fixed)
ViewportVisibility	67	Space-that is, model or paper space (fixed)
ViewportActive	68	APP: identifies whether viewport is on but fully off screen; is not active or is off
ViewportNumber	69	APP: viewport identification number
CircleSides, Int16, LinetypeAlign, LinetypePdc, RegAppFlags, TxtStyleFlags, ViewMode, ViewportGrid, ViewportIcon, ViewportSnap, ViewportSnapPair, ViewportSnapStyle, ViewportZoom	70-78	Integer values, such as repeat counts, flag bits, or modes
Int32	90-99	32-bit integer values
Subclass	100	Subclass data marker (with derived class name as a string). Required for all objects and entity classes that are derived from another concrete class. The subclass data marker segregates data defined by different classes in the inheritance chain for the same object. This is in addition to the requirement for DXF names for each distinct concrete class derived from ObjectARX (see "Subclass Markers")
EmbeddedObjectStart	101
ControlString	102	Control string, followed by "{" or "}". Similar to the xdata 1002 group code, except that when the string begins with "{", it can be followed by an arbitrary string whose interpretation is up to the application. The only other control string allowed is "}" as a group terminator. AutoCAD does not interpret these strings except during drawing audit operations. They are for application use
DimVarHandle	105	Object handle for DIMVAR symbol table entry
UcsOrg	110
UcsOrientationX	111
UcsOrientationY	112
XReal	140
ViewBrightness	141
ViewContrast	142
Int64	160	64-bit integer values
XInt16	170	16-bit integer values
NormalX	210	Extrusion direction (fixed)DXF: X value of extrusion direction APP: 3D extrusion direction vector
NormalY	220	DXF: Y values of the extrusion direction
NormalY	230	DXF: Z values of the extrusion direction
XXInt16	270
Int8	280	8-bit integer values
RenderMode	281
Bool	290-299	Boolean flag value
XTextString	300-309	Arbitrary text strings
BinaryChunk	310-319	Arbitrary binary chunks with same representation and limits as 1004 group codes: hexadecimal strings of up to 254 characters represent data chunks of up to 127 bytes
ArbitraryHandle	320-329	Arbitrary object handles; handle values that are taken "as is." They are not translated during INSERT and XREF operations
SoftPointerId	330-339	Soft-pointer handle; arbitrary soft pointers to other objects within same DXF file or drawing. Translated during INSERT and XREF operations
HardPointerId	340-349	Hard-pointer handle; arbitrary hard pointers to other objects within same DXF file or drawing. Translated during INSERT and XREF operations
SoftOwnershipId	350-359	Soft-owner handle; arbitrary soft ownership links to other objects within same DXF file or drawing. Translated during INSERT and XREF operations
HardOwnershipId	360-369	Hard-owner handle; arbitrary hard ownership links to other objects within same DXF file or drawing. Translated during INSERT and XREF operations
LineWeight	370-379	Lineweight enum value (AcDb::LineWeight). Stored and moved around as a short. Custom non-entity objects may use the full range, but entity classes only use 371-379 DXF group codes in their representation, because AutoCAD and AutoLISP both always assume a 370 group code is the entity's lineweight. This allows 370 to behave like other "common" entity fields.
PlotStyleNameType	380-389	PlotStyleName type enum (AcDb::PlotStyleNameType). Stored and moved around as a short. Custom non-entity objects may use the full range, but entity classes only use 381-389 DXF group codes in their representation, for the same reason as the Lineweight range above.
PlotStyleNameId	390-399	String representing handle value of the PlotStyleName object, basically a hard pointer, but has a different range to make backward compatibility easier to deal with. Stored and moved around as an Object ID (a handle in DXF files) and a special type in AutoLISP. Custom non-entity objects may use the full range, but entity classes only use 391-399 DXF group codes in their representation, for the same reason as the Lineweight range above.
ExtendedInt16	400-409	16-bit Integers
LayoutName	410-419	String
ColorRGB	420
ColorName	430
Alpha	440
GradientObjectType	450
GradientPatType	451
GradientTintType	452
GradientColCount	453
GradientAngle	460
GradientShift	461
GradientTintVal	462
GradientColVal	463
GradientName	470
Comment	999	DXF: The 999 group code indicates that the line following it is a comment string. SAVEAS does not include such groups in a DXF output file, but OPEN honors them and ignores the comments. You can use the 999 group to include comments in a DXF file that you've edited
ExtendedDataAsciiString	1000	ASCII string (up to 255 bytes long) in extended data
ExtendedDataRegAppName	1001	Registered application name (ASCII string up to 31 bytes long) for extended data
ExtendedDataControlString	1002	Extended data control string ("{"or "}")
ExtendedDataLayerName	1003	Extended data layer name
ExtendedDataBinaryChunk	1004	Chunk of bytes (up to 127 bytes long) in extended data
ExtendedDataHandle	1005	Entity handle in extended data; text string of up to 16 hexadecimal digits
ExtendedDataXCoordinate	1010	A point in extended data DXF: X value (followed by 1020 and 1030 groups) APP: 3D point
ExtendedDataWorldXCoordinate	1011	A 3D world space position in extended data DXF: X value (followed by 1021 and 1031 groups) APP: 3D point
ExtendedDataWorldXDisp	1012	A 3D world space displacement in extended data DXF: X value (followed by 1022 and 1032 groups) APP: 3D vector
ExtendedDataWorldXDir	1013	A 3D world space direction in extended data. DXF: X value (followed by 1022 and 1032 groups) APP: 3D vector
ExtendedDataYCoordinate	1020	DXF: Y and Z values of a point
ExtendedDataWorldYCoordinate	1021	DXF: Y and Z values of a world space position
ExtendedDataWorldYDisp	1022	DXF: Y and Z values of a world space displacement
ExtendedDataWorldYDir	1023	DXF: Y and Z values of a world space direction
ExtendedDataZCoordinate	1030	DXF: Y and Z values of a point
ExtendedDataWorldZCoordinate	1031	DXF: Y and Z values of a world space position
ExtendedDataWorldZDisp	1032	DXF: Y and Z values of a world space displacement
ExtendedDataWorldZDir	1033	DXF: Y and Z values of a world space direction
ExtendedDataReal	1040	Extended data floating-point value
ExtendedDataDist	1041	Extended data distance value
ExtendedDataScale	1042	Extended data scale factor
ExtendedDataInteger16	1070	Extended data 16-bit signed integer
ExtendedDataInteger32	1071	Extended data 32-bit signed long

VB.net Programming for AutoCAD, Civil 3D, and Map 3D

Over my 15 years of using AutoCAD and other Autodesk software, I've fooled around with writing LISP routines to a very beginner type extent. I've taken classes at Autodesk University on LISP and some of the APIs of the various softwares, but it's been over my head for a lot of it. Within the last month or so, I finally decided to start learning VB.net programming. After a few weeks into it and some coaching help from a friend, I finally wrote my first command - needless to say I am hooked.

The command I wrote automates a process in Map 3D that I despised doing. The process involves labeling GIS data of soil boundaries. I typically bring these in from a SHP file, Create Object Data, and import as polylines. From here the labeling process begins with the Map Annotation commands. To initiate the annotation, the user must first define a template for the annotation, in this case a Soils Label. Within the template, Edit Annotation Text msut be inserted (typically with the "MAPANNTEXT" command). This text is a special kind of attibute text that allows for accessing the Object Data Tables and Fields. Thus the user would browse to the correct table and field to generate labels based on the selected boundary's Object Data. From here the template would be saved.

Upon completion of the template, the user would then use the Map Annotation Insert template command, call up the created template and could insert once at a picked point, or insert for entire drawing at the centroid of the object. Typically the fastest way to do this is via the centroid of the object, however, the centroid does not always occur within the soil boundary - thus you would then have to move the labels around and check properties of each boundary to ensure the label is inside the correct boundary.

My VB.net command automates this entire process, which in turn saves a lot of trivial time of moving labels around. Basically to explain the command in english, it first calls up the dialog shown below and provides some instruction. It then auto populates the Table Name based on the Object Data in the drawing, then allows for the user to type in the corresponding Field Name for the soil name. From here the user can click "Label Boundaries" in which the program checks to see if an annotation template with the name of SoilLbl has been created. If not it creates the template based on the given prompts on the dialog.

Next it prompts the user to select a boundary to label, then prompts for label insertion point and repeats the label insertion point prompt until the user hits escape. Essentially this allows the user to lable one boundary at a time, ensuring for more accurate labeling of soil boundaries, and less time involved of going through the above process. 

I would like to encourage everyone to jump into the coding!! It opens a whole new realm of AutoCAD, Civil 3D, and Map 3D.

Civil 3D Labels Showing "XREF Moved"

Last week I ran into an issue where a drawing's Civil 3D labels were displaying XREF Moved as shown in the image below:

I did some research and found a blog regarding this issue (a link to the blog can be found at the bottom of this page). Though the blog's reasoning for this error may be correct, I found that it was not the solution to the issue I was having. After further research in the drawing, I found that indeed, the XREF had actually been moved. The labels were creating by lableing contours through the XREF, thus when the XREF was moved the labels reflected the error - kudos to Autodesk for thinking of this. Had the labels not stated the XREF was moved, it may not have been noticed by anyone reviewing plans as it was moved a very minor amount.

Track back to original blog solution that was not the solution of my problem.
http://beingcivil.typepad.com/my_weblog/2009/04/xref-moved.html

Chicago Civil 3D User Group

Last we Tuesday we held the first group meeting for the Chicago Civil 3D User Group. It was a success thanks to everyone who came out with interest and support. We had 12 attendees. The next group meeting will be on Tuesday, April 17th from 7:00pm-8:30pm. Definitely looking forward to that meeting as we will be covering the new features of AutoCAD Civil 3D 2013.

Should you or anyone you know be interested in the group, you can view the group page on LinkedIn here: Chicago Civil 3D User Group Page.

Chicago Civil 3D User Group - Collaboration Meeting

Please join us for the first meeting of the Chicago Civil 3D User Group. We are calling it a Collaboration Meeting, to kickoff the group and get everyone’s input on how to make the group successful. Please see the attached PDF for details. Feel free to share the event as well.

Please be sure to RSVP to me by Friday, March 23^rd, so we can plan accordingly for space and refreshments.

Chicago Civil 3D User Group

Since moving to Chicago, I've been looking to get involved and interact with other Civil 3D and CAD users and have been unable to find a professional group to join. So, I am starting one!! If you know of anyone in the Chicago region that uses the software interested in joining, please direct them to the LinkedIn group called "Chicago Civil 3D User Group". Looking to have the first group meeting sometime in March.

Autodesk Subassembly Composer for AutoCAD Civil 3D

For those of you Civil 3D users that are big fans of corridors, like me, Autodesk has unveiled the new Subassembly Composer (SAC) recently. I had taken a couple overview classes at Autodesk University this last year, and have been using ever since. For me, SAC brings a whole fresh new aspect to Civil 3D. SAC allows users to create their own fully functioning custom subassemblies that can range from very simplistic to extremely complicated with various programming built in. These custom subassemlies can be huge time savers on projects.

Subassembly Composer Overview

The SAC program has a fairly simplistic interface with various panels that can be moved around the screen for customization. I'd recommend leaving everything where it is, as it makes sense, everything seen is used. See image below.



The left hand side contains items in your tool box. If you're familiar with looking through the help menus of various "out of the box" subassemblies, then many of these items will make sense to you.

The center of the window contains the subassembly flowchart. This area helps you visualize how the tools chosen from the tool box relate to one another. From a user standpoint, keeping things clean and organized will make creating a subassmebly much easier. The window directly below the flowchart contains the properties of the tools used. Simply click on an item, and the properties of that item show below.

The lower right window contains several tabs. The first tab, "Packet Settings" allows you to add a subassembly name (referenced in Civil 3D tool space), description of the subassmebly (again referenced in Civil 3D tool space), a help file (PDF, DOCX, or other), and graphic image (for viewing in Civil 3D tool space). Note that the help menu currently does not work for custom subassemblies within Civil 3D; this is a known bug that has not been fixed as of yet.

The next tab is for Input/Output paramters, these show up under subassembly properties, parameters tab within Civil 3D and allow the end user to enter custom values for the components designed in subassembly composer.

The third tab is for Target Parameters such as surfaces, offset targets, and elevation targets. The fourth tab contains super elevation data should that be needed, and the last tab is for the event viewer. I have only dealt with the first three tabs thus far.

The upper right window, called the preview, is probably one of the most helpful areas of the program. This area displays what the subassembly you are creating should look like, with a few limitations. Items I've noticed are when you apply a surface target, an offset targe, or an offset elevation target to the subassembly,the display changes per the preview settings, on the Target Parameters tab mentioned above. Thus causing the display of the design subassembly to appear differently than you'd expect. I'd recommend adding offset and elevation targets into the subassembly design last to avoid this.

The help menu of SAC is pretty good. It seems to be a forum where users can add information, yet with some sort of control as to what information is added. There are several packet files out there for download to visually see how to use each tool. This was probably the best way that I learned how to use the program. Open up one of the PKT files and view the data, click through the various tools and notice the properties programmed for each. Another good method in learning the software is to try and create one of the simple "out of the box" subassemblies within subassembly composer.

Creating a Subassembly

Firstly, in creating your own subassembly, you have to have a great inspiring idea. However, be sure to not pick something too difficult to handle, or you can quickly become disatissfied that your custom subassembly does not work. My first subassembly turned out to be too difficult to achieve at first, so I had to find another that I could actually complete.

I have been using the Civil 3D subassembly BasicSideSlopeCutDitch subassembly for quite a while and have found it extremely useful in roadway design. In more than one circumstance, engineers have requested that I carry the channel along the toe of the fill slope to pick up additional drainage (as shown in the image below). This can be a difficult process without the use of SAC, basically adding a corridor, then grading in an additional channel with grading groups or corridors, and pasting surfaces together. Thus I had the idea to recreate the BasicSideSlopeCutDitch, but modify it to include a channel in the fill section.

The flowchart for this subassembly is shown in the SAC overview image above and basically begins with a point that would be the hinge point of the subassembly and setting a target surface in the target parameters (set the surface preview to something greater than 0, while point 1 should be a 0,0. Next add in an auxiallry point, auxillary tools are temporary calculation tools and do not show up in Civil 3D visibly. The auxiallry point, needs to be set on the target surface, thus the properties type should be set to "Delta X on Surface", form point can either be point 1 or origin, Delta X would be 0, surface target is the target surface.

Next add in a decision; this is a conditional tool allowing you to provide input for a true/false situations. We need to tell the subassembly to determine if it is in a cut or fill situation. Under the properties of the decision the conditional value needs to check both the auxillary point 1 and point 1 Y values in relation to the target surface. Thus if you type "AP1.Y<P1.Y" you are telling the subassembly that if the distance to surface of the auxillary point is less than the distance to surface of the point, then perform the true option, if not perform the false option. The false option can be renamed to Cut and the true option can be renamed to fill, for organization. The left side of the decision tool is always the true value and the right side is always the cut value.

Next add in a point for both the cut side and the fill side. Connect lines to each from each side of the decision tool, you should see the Fill and Cut text show up in the line. Before moving forward, we need to add in user inputs. Add the following user inputs with the columns in order following, name, type, direction, default value, display name:

• Side, Side, Input, Right, Side
• ForeslopeSlope, Slope, Input, 2.00:1, Foreslope Slope
• CutSlope, Slope, Input, 2.00:1, Cut Slope
• FillSlope, Slope, Input, 2.00:1, Fill Slope
• ForeslopeWidth, Double, Input, 5, Foreslope Width
• BottomWidth, Double, Input, 2, Bottom Width
• Backslope Slope, Slope, 2.00:1, Backslope Slope
• BackslopeWidth, Double, Input, 5, Backslope Width

Next, add in points so there are a total of 4 points for each cut/fill situations; add flowchart arrow lines to connect each together. Points should reference the previous point, beginning with point 1. Lines should also be added to connect the points, notice the preview update as the information is added.

Next we need to added properties to each of the points starting with the first point on the cut side. This will be the first slope in the ditch, thus we know what the foreslope slope should be and we know what the foreslope width should be from the parameters created above. Make the point type to be "Slope and Delta X", set the slope to "-ForeslopeSlope", and the Delta X to "ForeslopeWidth". Next we need to establish the bottom of the ditch. This we know the bottom width and the bottom is flat, thus we can use the type "Angle and Delta X" where the angle will be "0" and the Delta X will be "BottomWidth". The next segment is the backslope of the channel and should be programmed similar to the foreslope and the last segment will tie from the top of the backslope to the surface. This segment will have a type of "Slope to Surface" using the CutSlope parameter as the slope and the target surface parameter as the surface target. The preview window should be taking shape now.

The fill slope side will be very similar to the cut slope side, however, the first segment should target the target surface at the fill slope first, then proceed into the foreslope of the channel, add in the bottom width, then target the target surface a second time to close the channel. This will not need a backslope as if a backslope is added, there is the possibility of passing the target surface and thus creating a berm, blocking drainage.

Final cleanup of the subassmebly should involve going through each of the points and lines and adding in point codes and codes for the objects. These should be entered in a similar fashion, ie "Top" and "Datum" should be added to all to create a top surface and datum surface on the subassembly.

Recommended Organizational Methods

For ease on end users, I recommend that prior to finalizing your subassemblies, study the help menu of similar "out of the box" subassemblies and use the same format Autodesk does for Input/Output Parameters, Targer Parameters, Point Codes, and Codes. Keeping various tools in line with one another in the flowchart will make it much easier to follow while programming. Click on a tool and drag, or use the arrow keys for a more refined movement.

Help menues should be made up to look similar to the "out of the box" help menus, at a minimum to provide the same type of information, schematics, and order.

Icons should be of the same format as ones provided. Starting with an "out of the box" icon is a great way to develop a nice looking icon. Program icons can be found here: C:\ProgramData\Autodesk\C3D 2011\enu\Tool Catalogs\Road Catalog\Images

Using the Subassembly in Civil 3D

Using the subassembly in Civil 3D is pretty easy. Simply right click on your tool palette, add a new custom palette, and import subassemblies. Browse to the PKT file saved by subassembly composer, select, and hit ok. Subassembly is now ready for use on the palette the same way all others are used.

Other users who do not have Subassembly Composer installed will need to download and install a patch from Autodesk.