Architect or LandmarkConcept: Site model modification


Tool set

Site Modifiers


Site Planning

As discussed in Concept: Sitework overview, when the site model is generated, two different display modes of the site model object are available—existing and proposed. The existing site represents the site prior to your project; the proposed site incorporates the project’s changes. To modify the site model, use the Site Modifiers tool, along with other site modification tools in the Vectorworks program; a site modifier can be applied to either the existing or proposed site model.

Each site modifier defines its own surface; the site model uses that surface as it generates the site model surface outside the modifier area. A site modifier can be nested inside another site modifier. Site model generation builds a hierarchy of nested modifiers, applies them in order, and stitches their surfaces together to produce the final site model surface.

There are two types of modifiers: closed surface and open surface modifiers.

The closed surface modifiers—planar pad, pad with retaining edge, aligned, path, texture bed, and spoil pile—define a parametric surface inside a closed area. The grade limits closed modifier is an area containing surface modifications; the area defines the transition surface between the modifiers that lie inside the area and the rest of the site model surface.

Each of the closed surface modifiers provides its own surface, which is placed into its parent’s surface, ultimately producing the final site model surface.

The open surface modifiers—open edge line, pathway path, grade object, and stake object—ensure triangulation in the area matching the elevation along the lines of the open surface modifier (not necessarily along the contour lines).

The Site Modifiers tool has several modes. 




Grade Limits

Defines an area of topographical transition between existing site data and the site modifiers enclosed within the limits

Open Edge Line

Creates an open path site modifier

Planar Pad

Draws a closed area which modifies the site model

Pad with Retaining Edge

Creates a pad with an edge around it, allowing the terrain to be shaped around the pad


Creates an aligned pad that vertically matches the horizontal edges of surrounding modifiers. Aligned pads are complex, non-planar modifiers that can also be modified with vertical profiles, stake objects, and grade objects.

Pathway Path

Creates a surface defined by one longitudinal profile and a set of transverse profiles, defined by a pathway/center line polyline and a specified width value

Boundary Path

Creates a surface defined by one longitudinal profile and a set of transverse profiles, defined as a boundary polyline with a center line based on the boundary

Texture Bed

Creates an area of the site model that can be textured

Spoil Pile

Creates an area where excess earth can be used to help balance the cut and fill

Snap to Contour Elevation

Constrains the site modifier to the site model contour elevation under the cursor when the site modifier is created. The contour under the cursor is highlighted, and the elevation of that contour is used as the modifier elevation.

Polyline creation options

Selects the method for drawing the polyline upon which the site modifier is based; see Creating polylines


Sets the default preferences for the site modifier

Pad Elev

Specifies the initial elevation of the site modifier

Site modifiers can be placed on any layer. The site model properties specify whether modifiers in another layer can affect the site model (see Creating the site model). You might put various site modifiers on separate layers, for example, so that you can show each modifier’s effect on the site model individually. When a site modifier is placed in the drawing, the Site-DTM-Modifier class is created automatically.

In addition to the site modifiers that are created with the Site Modifiers tool, a number of other tools and commands create objects that can modify the site model.

Creating grade limits

Creating an open edge line modifier

Creating a planar pad or pad with retaining edge

Creating an aligned site modifier

Creating a pathway or boundary modifier

Creating a texture bed

Creating a spoil pile area

Creating roads

Creating NURBS roadways

Creating landscape walls

Creating hardscape objects

Showing and hiding site modifiers

Creating property lines

Analyzing the site model

Obtaining site model data


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