Template Details: Components
Create Template - Components and Constraints
Each Component within the FLH Template Library has different properties. Barriers, Curbs, Guardrail, Medians, Overlay, Paved Ditch, Pavement, Retaining Walls, Shoulders, Sidewalk, and a few Misc Components have been predefined. When using the template library, some properties of these components can be revealed by selecting the Active Template tab and by using the Display options (as shown in the image below).
A Component is a set of points that define an open or closed shape. Each component, whether open or closed, can represent a different material or area of interest. Components are named and have an assigned feature style. There are 6 types of components: Simple, Constrained, Unconstrained, Null Point, End Condition, and Overlay/Stripping.
A Component can be modified as desired when developing a Project Template library. There is no limit to the number of points or components in a template. When templates are paired with horizontal and vertical alignments and superelevation, they define the surface of a corridor. Templates are flexible design components that allow you to model simple constructs such as ditches and sidewalks to the more complex multi-lane highways with superelevated curves and variable side slopes.
- A Simple Component typically represents a section of pavement. It's a closed parallelogram (4 constrained points) that is defined by the slope and thickness.
- A Constrained Component consists of points that are all restricted to the movement of the first point.
- An Unconstrained Component is open or closed-shaped with no movement restrictions.
- A Null Point is a template point that is purposely not related to any particular component. It's most often used as a reference for controlling other points.
- An End Condition is a special open-shaped component that targets a surface, a feature of a surface, an elevation, or an alignment.
- An Overlay/Stripping Component is used to handle all milling/stripping operations and this component can be used to handle leveling/overlay tasks. Also, the Overlay/Stripping component can be used for topsoil placement along with existing pavement, shoulder, and sidewalk.
Constraints are used to manage the behavior of template points. They are used so that if a point is moved in a template, either by the user editing the template or by the application of point controls during design processing, all the points related to the point being moved will behave in a predictable manner. Constraints can also be labeled so that during the design process the value of labeled constraints may be changed.
NOTE: A constrained point is typically used to manage the behavior of other points in the template. When a point (parent) is moved, any constrained point (child) also moves. This restriction only affects the offset and elevation (x,y) of the restrained point and, the relationship is unidirectional (movement of child point does not move the parent point).
There are a variety of constraint types for roadway template design. Click on the name for a graphic detail of each type of constraint:
- Horizontal Maximum
- Horizontal Minimum
- Vertical Maximum
- Vertical Minimum
- Vector Offset
- Project to Surface
- Project to Design
- Angle Distance
The image below represents a Pavement Component with the display option 'Constraints' activated:
Parametric Constraints are used to change the value of a predefined constraint within a template. The label field in the constraints portion of the point properties dialog box displays the optional label for the constraint. Constraints that are labeled can have their value changed during design processing. The same label name can be assigned to more than one constraint and more than one point.
EXAMPLE: A Pavement Component may have a constraint label called thickness that controls the thickness of the wearing surface. This thickness can be changed so that one template can be used for different pavement depths, without having to edit the template.
Style Constraints on a point override the point contraints if a feature or alignment with a matching style is found within a specified horizontal range. The image below shows a Style (PL_Exist. Pavement) is being used to control the horizontal location of the edge of travel way point (Pvmt_ETW_LayerTop).
The type or mode allows you to select the constraint type: Horizontal, Vertical, or Both. A Range specifies the maximum horizontal distance to search from the point's current location to any feature or alignment with the specified style. Only the active surface and active geometry project is searched. Negative values cause the search to be to the left; positive values to the right. A value of zero causes the search to find the closest instance of the style.