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AutoCAD

CAD Clinic: Civil 3D -- Surface Object Styles

6 Aug, 2006 By: Phillip Zimmerman

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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.

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

Task/Style	Labels	Internal/ External	Component List	2D/3D	Layers
Create and evaluate a surface under development	Tooltips	Internal	Border, Point, Triangles	2D/3D	Standard Layers
Analysis -- Flood Plain	Flood Contour	Internal/ External	User Contours Elevations	2D/3D	Standard Layers
Analysis -- Slope and Arrows/Water Flow	Spot Slopes	Internal	Slope/Slope Arrows Rain Trails	2D/3D	Standard Layers
Analysis -- Elevations	Spot Elevation	Internal	Elevations	2D/3D	Standard Layers
Analysis -- Volume Calculations Review	Depth, Spot Elevations	Internal/ External	TIN Volume, Grid Volume, Contours, User Contours 3D/Elevations	2D/3D	Standard Layers
EG Contours	Contour, Spot Elevations	Internal/ External	Major/Minor Contours Elevations	2D/3D	Standard Layers
Design (FG) Contours	Contour, Spot Elevations	Internal/ External	Major/Minor Contours Elevations	2D/3D	Standard Layers

Many of these styles apply to existing conditions and design surfaces.

Styles List
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).

View Direction
If using 2D and/or 3D view directions, what are the layer names and visibility settings?

Layer Names
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).

Border Tab
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.

3D Geometry
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.

Border Types
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).

Datum
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).

Points
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.

Triangles
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).

Display
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).

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.