Create a Terrain Model from Existing Objects

Description

Creates a terrain model from selected objects.

Access

Home / Tools / Create / Terrain Model / Existing Objects

Requirements

Controls

Control	Description
Name	Type the name to assign to the created terrain model or click to use the next available auto incremented name.
Use name as layer	Do one of the following: Select the checkbox to create the terrain model on a layer with the same name as the terrain model. Clear the checkbox to create the terrain model on the active layer. Note: The created layer is based on the defined template layer or the active layer if a template is not defined. Ensure the name is a valid layer name.
Search Distance	Enter the distance that the terrain model formation algorithm should search for suitable apexes.
Segment Straights	Select to insert vertices to be used in the creation of the terrain model, if straight breaklines contain segments exceeding the Maximum Distance.
Maximum Distance	Maximum distance between vertices in a straight line segment.
Segment Circular Arcs	Select to create vertices to be used in the creation of the terrain model if the Tolerance is exceeded for circular arc breaklines.
Tolerance	Maximum offset distance between a circular arc and the chord between adjacent vertices in the circular arc.
Segment Splines	Select to create vertices to be used in the creation of the terrain model if the Tolerance is exceeded for spline breaklines.
Tolerance	Maximum offset distance between a spline and the chord between adjacent vertices in the spline.
OK	Create the terrain model.
Validate	Generate the model and a report without saving the model.

Notes

An objects vertices are considered in the creation the terrain model if:
- the object is selected at the time the terrain model is created.
- the object has the Use in Terrain Model property set to Yes, OR By Layer AND the Use in Terrain Model checkbox is selected for the objects layer.
- the vertices has 3 dimensional coordinates.
The created terrain model consists of numerous triangular faces.
The Appearance properties of terrain models are set by the layer but can be overridden via the Attributes tab.
Any selected lines or polygons that are classified as breaklines will be used to control the terrain model formation and considered for segmenting.
Segmenting does not insert vertices into the breakline, it inserts vertices along the line to be used in the formation of the model.
Validate the terrain model prior to creating and resolve any issues.
If breaklines cross, only one of the breaklines is used. Remove one of the breaklines from the selection.
A breakline or boundary that contains any vertices with a default height is ignored.
Any selected polygons that are classified as boundaries will be used to bound the terrain model.
Heights of vertices inserted in to segmented lines are linearly interpolated between the existing vertices.
Reduce the Search Distance value to help prevent the formation of long thin faces.
To create a hole in a terrain model, first join the polygons defining the inner and outer boundaries.

Possible errors

A Create Terrain Model Report window is displayed if there are any warnings or errors.

Error	Description	Recommended Solution
Insufficient vertices with valid heights to form model.	A model could not be formed using the existing selection and constraints.	Ensure you have selected at least 3 three dimensional vertices within the search distance.
Breakline between vertices {uid} and {uid} crosses breakline between vertices {uid} and {uid}. Breakline ignored.	Two breaklines cross, or a break line crosses over itself. The line or line segment listed first has not been included in the model.	Recreate the model, removing one of the breaklines or line segments from the model. If there is an error in the breakline you should resolve the issue or delete it from the project.
Vertices {uid} and {uid} are coincident.	Two selected vertices share the same x and y location. The difference in the vertices coordinates are reported. Only one of the vertices is used in the model.	Recreate the model, removing the unwanted vertex from the selection.
Vertex {uid} with default height is used in a breakline ({uid} - {uid}). Breakline ignored.	The entire breakline is ignored if it includes a vertex with a default height.	Insert a height for the vertex, or remove the breakline from the selection.
Vertex {uid} lies along the breakline from {uid} to {uid}. Breakline ignored.	A selected vertex's x and y location is on a breakline.	Recreate the model, removing either the breakline or vertex from the model.