Each subassembly included in the AutoCAD Civil 3D Corridor Modeling catalog has a Help file that provides detailed construction and behavior information. You can display the Help file for the AutoCAD Civil 3D Corridor Modeling subassemblies using any of the following methods:
- From a Tool Palette. Right-click a subassembly in a tool palette, then click Help.
- From a Tool Catalog. Right-click a subassembly in a tool catalog, then click Help.
- From the Subassembly Properties dialog box Parameters tab. Right-click a subassembly in the Prospector tree, then click Properties
Parameters tab Subassembly Help.
When creating custom subassemblies, you should also create a custom Help file to accompany the subassembly. You can use a Microsoft Compiled HTML Help file (.chm) to create the subassembly Help file. The Help file content and style should be similar to that in the AutoCAD Civil 3D Subassembly Reference Help. The table below describes the sections that should be included, as a minimum, in subassembly Help files. This information is required so that users understand the subassembly behavior and intended use.
| Section | Description |
|---|---|
| Title | The name of the selected subassembly should appear prominently as the top heading of the subassembly Help file. |
| Descriptions | A brief description of the subassembly that includes the type of component the subassembly creates (for example, a lane, median, or shoulder), special features, and situations it is designed to cover. |
| Subassembly Diagram | The subassembly diagram should be a schematic showing the geometry of the component that is created by the subassembly. Diagrams should label as many of the input parameters as feasible, especially those pertaining to dimensions and slopes. You may need to include multiple subassembly diagrams for different behavior and/or conditions in order to include all of the possible input items. The subassembly diagram should also show the subassembly reference point, which is the point on the subassembly where it is attached when building an assembly layout. It is useful to adopt diagramming conventions that help the user understand the operations. For example, the subassemblies included in the AutoCAD Civil 3D Corridor Modeling catalog use bold blue lines to represent links that are added to the assembly by the subassembly. This helps to show adjacent roadway components that the subassembly might attach to in a lighter line with a background color. Ideally, dimension lines and labels should also be a different color. |
| Attachment | Describes where the attachment point is located relative to the subassembly links. |
| Input Parameters | Describes each of the user-definable input parameters that can be specified when using the subassembly. These should precisely match the parameter names and order seen by the user when using the assembly layout tool, and should describe the effect of each parameter. These are best presented in a table that includes a description of each parameter, the type of input expected, and default values for metric or imperial unit projects. For input parameters for slope values, note that there are two common ways of specifying slopes: as a percent value like -2%, or as a run-to-rise ratio like 4 : 1. Any slope parameter should clearly specify which type is expected. In the subassemblies included in the AutoCAD Civil 3D Corridor Modeling catalog, the convention is to precede the word “Slope” with the “%” character in the parameter name if a percent slope is expected. Otherwise a ratio value is required. Note the practice of using positive numeric values for both cut and fill slopes. If a slope parameter is known to be used only in a fill condition, it should not be necessary for the user to have to specify a negative slope value. However, in a more generic situation, for example with the LinkWidthAndSlope subassembly, a signed value may be necessary. |
| Target Parameters |
Describes the parameters in the subassembly that can be mapped to one or more target objects. Input parameters are defined when building an assembly in layout mode. Target parameters are substitutions that can be made for input parameters when applying the assembly to a corridor model. Typically, subassembly parameters that can use a target object to define a width or an offset can use the following types of objects to define that width or offset: alignments, AutoCAD polylines, feature lines, or survey figures. Similarly, subassembly parameters that can use a target object to define an elevation can use the following types of objects to define that elevation: profiles, AutoCAD 3D polylines, feature lines, or survey figures. Subassemblies that can use a target object to define a surface can only use a surface object to define that surface. A few subassemblies allow you to use pipe network objects as targets, such as the TrenchPipe subassemblies. A typical scenario is a travel lane where the width is a numeric input parameter, which can use an alignment as a target parameter to replace the numeric width. The given numeric width is used when displaying the lane in layout mode. If an alignment is given, the width is calculated at each station during corridor modeling to tie to the offset of the alignment. For more information, see Setting and Editing Targets in the AutoCAD Civil 3D User's Guide Help. |
| Behavior | Describes the behavior of the subassembly in detail. If necessary, this section should include diagrams showing different behaviors in different conditions. This section should provide both the subassembly programmer and the end user with all of the information needed to understand exactly what the subassembly does in all circumstances. Subheadings are recommended if the Behavior section covers several different topics. |
| Layout Mode Operation | During the process of creating an assembly from subassemblies, also known as the assembly layout mode, specific information such as alignment offsets, superelevation slopes, profile elevations, and surface data, are not known. The Layout Mode Operation section of the subassembly Help file describes how the subassembly is displayed in the assembly layout mode. Layout mode refers to an assembly that has not yet been applied to a corridor. Some subassemblies behave differently in different situations. For example, a Daylight type of subassembly may create different geometric shapes depending on whether it is in a cut or fill situation. Shoulders may behave differently for normal crown and superelevated roadways. In layout mode, the subassembly designer must specify some arbitrary choices as to how the subassembly is displayed. It should appear as much like the final result in the corridor model as possible. Lanes and shoulders, for example, should be shown at typical normal crown slopes. Where there is alternate geometry, such as for the cut and fill daylight cases, both cases should be shown. Also, links that extend to a surface should be shown with arrowheads indicating the direction of extension. |
| Layout Mode Diagram | A diagram illustrating layout mode behavior and visual representation is useful if layout mode behavior and/or visual representation of the subassembly differs significantly between layout mode when the assembly and its associated subassemblies are applied to a corridor. |
| Point, Link, and Shape Codes | Describes the items that are hard-coded into the subassembly, including dimensions, point codes, link codes, and shape codes. Common practice is to reference the point, link, and shape codes to labels on the coding diagram. |
| Coding Diagram | The coding diagram has a twofold purpose. First, it labels the point, link, and shape numbers referred to in the previous section. Secondly, it provides the subassembly programmer with a numbering scheme for points, links, and shapes. These should correspond to the array indices used in the script for points, links, and shapes. This is to make it easier to later modify or add to the subassembly. |
After creating the custom Help files for custom subassemblies, you must reference the Help files in the tool catalog .atc file associated with the subassemblies. For more information, see Sample Tool Catalog ATC File.