CAD Clinic: Civil 3D -- Surface Object Styles7 Aug, 2006 By: Phillip Zimmerman
Discover how to create components, view directions and control layers for a surface object style.
Civil 3D has three basic style groups: object, label and table. The purpose of an object style is displaying an object's components and assigning layer names and properties. Some object styles are used internally, while others focus on submission documents. For example, internal surface styles show triangulation or slopes and elevations for designers. The submission styles create documentation (e.g., contours and labels, tables, presentation quality exhibits, etc.).
1. How do I use ...?
When deciding to implement Civil 3D, the question is where to start. You should start by asking yourself how you use each Civil 3D object, what tasks are done with each one, how do you label them, is there a difference between internal and submission representations and do you need specific function styles? The answers to these questions create a list identifying implementation styles. In turn, the list becomes the basis for a matrix identifying the style names, function, labels, use, components, view directions and layer names.
2. List to Matrix
After creating a style list, the next step is building the matrix identifying the components used in each style. To determine the component list of an object, open any existing object style and view the contents of the Display panel. For each component listed in the Display panel, there is a tab or a section within a tab of the Object Style dialog box defining the component.
Each component has a 2D and 3D view direction that require layers and visibility control. Usually, the layers and visibility are the same for 2D and 3D. However, there are times a style has different 2D and 3D view values. The layer names in the style's Display panel should represent your standards.
If you want to use the content templates accompanying Civil 3D, you should evaluate the styles to see if you can use or modify them for your implementation (figure 1). If you can use them, just modify their values. If you cannot use the style, you still can review it and learn how develop this object style type.
Figure 1. Sample object styles for surface and profile views.
The remainder of this article goes through the process of identifying tasks, use, components, view directions and layers for a surface object style.
A surface object style is a good starting point when learning about object styles because each component has it own tab and the settings are straightforward. Surface Tasks
The first step is asking questions about the use of the object during the life of a project. Some example questions for surfaces are: When working with surfaces, do you develop surfaces (existing and proposed)? What do you ask of them? Do you calculate volumes? What labeling do they have (same or different for existing and proposed)? Are there different appearances between internal use or submission documents? What Styles Do I Need?
By answering the above questions, you develop a styles list. You will likely need several object styles: some for surface development and analysis, and others for submission documents. For example, when looking at the task of developing a surface, only the surface components of border, triangles and points are necessary. Those components, along with the Quick Profile routine, give you the best tools to evaluate and review a developing surface.
The Style Matrix
Create and evaluate a surface under development
Border, Point, Triangles
Analysis -- Flood Plain
Analysis -- Slope and Arrows/Water Flow
Analysis -- Elevations
Analysis -- Volume Calculations Review
Depth, Spot Elevations
TIN Volume, Grid Volume, Contours, User Contours 3D/Elevations
Contour, Spot Elevations
Design (FG) Contours
Contour, Spot Elevations
Many of these styles apply to existing conditions and design surfaces.
The styles list is an essential aspect of submission documentation, and the matrix identifies the types of labels you use to document critical surface values.
In-house or External
Is the style for in-house or external use? Internal styles are sometimes less formal than external styles.
List of Components
The components for a surface are: points, triangles, border, major contours, minor contours, user contours, gridded, elevation, slope, slope arrows and watershed. The matrix identifies the appropriate components for each surface style (development, analysis and documentation).
If using 2D and/or 3D view directions, what are the layer names and visibility settings?
If you are not using the Nation CAD Standards layer names, the layer names should be your office standard layer names.
Define a Border-Triangle-Points Surface Style
The first surface style addresses the task of developing a surface. The style displays a surface border, points and triangles.
If the style is a new style, the starting point is Settings / Surface / Surface Styles. You select the Surface Styles heading, right-click and select New from the shortcut menu.
In the Surface Style dialog box, select the Information tab and assign the style a name, Border-Triangle-Points (figure 2).
Figure 2. Information panel.
The Borders tab and its settings are next. The settings in the tab define the border's 3D geometry, the display of external and internal boundaries and a datum for the surface border.
The 3D Geometry component has three settings: Use Surface Elevation (different elevations at each vertex), Flatten to Elevation (same elevation at each vertex) and Exaggerated.
The Flatten to Elevation option sets the border to a single user-defined elevation. If the 3D geometry is set to Use Surface Elevation, each border vertex has the same elevation as the surface. When set to exaggerated, the surface border elevations are greater than the surface elevations.
There are two types of surface borders: external and internal. An external border is the outer boundary of the surface's triangulation. An internal boundary is a hide boundary or a hole in the surface. You produce an internal border when deleting triangles in the interior of a surface (a hole).
The datum is a skirt made from the border draping down to the datum elevation. For this effect set both Use Datum and Project Grid to Datum to true (figure 3).
Figure 3. Border panel.
Points have the same 3D geometry properties as the surface border.
A surface displays three types of points: data points, derived points and nondestructive points (figure 4). A data point is point data from assigned point groups or points added using the Add Point edit operation. The points display with the same color, unless you change their colors here. A derived point is a calculated point, e.g., a point used to remove flat triangles in a contour data surface. A nondestructive point is a point resulting from the use of a nondestructive breakline.
Figure 4. Point Display panel.
The Triangles panel controls how a surface displays its triangulation. The 3D Geometry settings are the same as for border and points; the Use Surface Elevation (different elevations at each vertex), Flatten to Elevation (same elevation at each vertex) and Exaggerated options (figure 5).
Figure 5. Triangles panel.
After setting all of the values for the border, point and triangles, none of the object components display unless you toggle on their display in the Display panel. The Display panel is where you set the layer names, visibility and 2D and 3D viewing values.
You view the surface in both 2D and 3D, so set the layers and visibility for both view directions (figure 6).
Figure 6. Display panel.
Implementing Civil 3D and Creating Styles
When starting a Civil 3D implementation, creating the correct object styles requires you to list the tasks for each object type. For example, do you create surfaces from field data or create proposed surfaces? What kinds of surface analysis do you do? Do you use their data as public exhibits, or do you submit them as a part of a plan set? Identifying object use also identifies labels types and how you document and represent concepts and designs to reviewers and clients.
Styles are the way you format data to communicate your design to all interested parties. Using styles makes the creation of the documentation repeatable and a consequence of the design rather that a drafting skills.
This and following articles focus on the task of evaluating object use, listing the components needed and how to create styles that implement and make Civil 3D reduce you drafting time and increase the quality of design.
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!