create_road

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Create Roads

This dialog box provides context sensitive help.

The Create Roads dialog box controls excavation of roads on the terrain surface:

•Road position is determined by the centre line drawn on the terrain surface.

•Road shape is controlled by parameters set in this Create Roads dialog box.

The centre line is drawn segment-by-segment, each time using current parameters. An explanation of the method used is found in the Road Creation topic.

The way in which 3d-DigPlus creates polygons and excavates the terrain is described in the Terrain Excavation topic.

The following is a description of the items in the Create Roads Window.

Items in the Create Roads Dialog Box

Road Name

This is the name of the current road whose parameters appear in the rest of the window. Parameters of excavated roads may not be altered, but may still be viewed. Parameters of unexcavated roads may be altered at any time.

Each road is numbered, in order of creation. A default road name is offered for each new road. This name may be altered by the user, by typing into the name field. After doing this be sure to press the Enter key or click the Save Button to make sure that the road name is kept.

New Road Button

This button creates a new road template. The complete Road Creation process can then be carried out for this road. Only then will it appear on the terrain surface.

Each road is numbered, in order of creation. A default road name is offered for each new road. This name may be altered by the user, by typing into the name field. After doing this be sure to press the Enter key or click the Save Button to make sure that the road name is kept.

Add Segments Button

This button allows the user to add segments to the road. Clicking this button causes the Create Roads Dialog boxto be temporarily closed. The green cursor becomes active on the current graphics window, and may be moved with the mouse over the terrain surface.

The start of the first segment is defined by simply moving the green cursor to the desired position on the terrain and clicking the left mouse button. The start of the first segment is located on the terrain surface.

Subsequent segments are also added by the same move and click operation. During movement of the green cursor, the smoothed road centre and road edges will be drawn along with the user-defined road segments. These are all drawn at their correct (East, North) coordinates, projected onto the terrain surface.

Clicking the right mouse button exits the Add Segments graphics mode and returns to the Create Roads Window. Segment parameters may then be altered, and additional segments add to or deleted from the road.

During the cursor movement the current cursor coordinates on the terrain surface, and its bearing and dip from the end of the previous segment will be shown on the status bar in the usual way. In addition the new segment slope (degrees below horizontal), segment end elevation and segment end offset from the terrain will be shown on the status bar as the cursor is moved to each proposed new segment position.

During cursor movement, the usual Esc and Backspace/Delete keys are active. The first press of the Esc key deletes all segments added during this session (i.e. since clicking the Add Segments Button) and remains in Add Segments mode. Another press of the Esc key returns to the Create Roads Window. The Del or Backspace keys delete added segments one at a time.

After the addition of each segment, the cut/fill balance figures for all segments up to and including that segment are shown in a table. This involves a reasonably lengthy calculation. This calculation can be disabled by turning off the Show Cut/Fill when adding segments flag on the Road Parameters page.

Last Segment Button

This button acts in the same way as the Add Segments Button. The only difference is that it adds the last segment to the road. The road may be formed on the terrain surface i.e. excavated only after the last segment has been added.

Excavate Button

This button excavates or fills the existing terrain to create the current road. Parameters of excavated roads may no longer be edited, but they may still be viewed. After excavation the smoothed road centre is still visible on the terrain surface. This may be hidden through the Show Road Features flag on the Excavate page in the Terrain Appearance Window.

Undo Excavate Button

This button returns the terrain to its shape before the road was excavated. The road parameters may then be edited and the excavation performed again. This undo operation may only be performed if no excavation or dumping was done after excavation of the given road.

Show Cut/Fill Button

This button shows a table of segment-by-segment cut, fill and nett (cut minus fill) material volumes for the road in its present configuration. This may be done at any time during road formation i.e. before or after placing of the last segment, or after the road excavation.

The material is shown both individually for each segment and also cumulatively i.e. summed for all segments up to and including each given segment.

The cut and fill volumes are shown in bank cubic metres or cubic yards. This means that all material volumes are converted back to bank volumes. The material swell factor used in this calculation is also shown on the table.

In addition, the segment slope (degrees below horizontal), segment end height and segment end offset are shown in the table for each segment.

This same table is optionally shown when segments are added to the road. As this may involve quite a lengthy calculation, it can be disabled through the Show Cut/Fill when adding segments flag.

Delete Road Button

This button deletes the road template and road feature, should it exist. If the terrain surface has been altered to form the road i.e. the road has been excavated, this excavation will not be affected by deleting the road with this button.

Delete Segment Button

This button deletes the last road segment present in the road.

Save Button

This button saves all changes made to the current road parameters. It has no effect on segment position or number of segments, which are saved independently after each Add Segments drawing session.

Close Button

This button closes the Create Roads Window. If some road parameter changes have not been saved, the user will be promted with the option to save them. This prompt has no effect on segment position or number of segments, which are saved independently after each Add Segments drawing session.

Parameters Page

This page contains parameters which apply to the whole road. These parameters do not differ from road segment to road segment. They are the Road Template parameters (road width and road crossfall).

Road Width

This is the plan view distance between the road edges. It is twice the distance from the smoothed road centre to each road edge.

Crossfall

This parameter determines the slope of the road surface perpendicular to the smoothed road centre. It is measured below horizontal. Positive values thus correspond to the road edges sloping away from the road centre.

Slope Units

This option allows the user to select the units (Degrees or Percent) to measure the slopes ( crossfall , cut/fill batter angles and segment slopes)

Show Cut/Fill when adding segments

This flag enables a calculation to show the cut/fill balance segment-by-segment each time a segment is added to the road. As this calculation may be quite lengthy, it can be disabled through this flag.

Segments Page

This page contains three sub-pages (Parameters, End Junction and End Height pages) which contain segment-specific parameters. It also contains the current road segment name.

Segment Name

Each road segment is named sequentially "Segment 1" "Segment 2" and so on. These names cannot be altered. This field shows the name of the segment whose parameters are currently displayed on the three Segment sub-pages.

The parameters of the next segment to be added are stored under the name "New Segment". This is not a current road segment, but merely serves to identify the parameters which will be used for the next added segment.

Segment Parameters Page

This page contains parameters whose value may vary from segment to segment.

Cut Batter Angle

The cut batter angle is used to merge the road edges with the terrain surface in sections where the road edge elevation is below the current terrain level.

The cut batter angle is the angle of the remaining material measured from the horizontal. So a smaller angle represents more removed material.

Fill Batter Angle

The fill batter angle is used to merge the road edges with the terrain surface in sections where the road edge elevation is above the current terrain level.

The fill batter angle is the angle of the filling material measured from the horizontal. So a smaller angle represents more added material.

End Junction Page

This page presents parameters which determine the type of smoothing will be used for smoothing road corners.

A road corner is formed at the junction of two user-defined road segments. Road corners are smoothed in 2D by replacing the corner by a smooth curve tangential to each segment. Three options are offered are offered for smoothing the corners.

End Junction Type

These options are independently applied to the junction of each segment with its next neighbouring segment. So more than one of these options may be used in a given road.

•linear

No smoothing is performed in this option. The user-defined road segments form the smoothed road centre directly.

•circular curve

Max. Radius

This option replaces the road corner with a section of a circle.

The max. radius parameter sets the position of the circle section for a given corner angle.

The smoothing curve never takes up more than half the length of a segment. So if the nominated max. radius is too large (i.e. a segment is too short) the actual radius is adjusted to occupy half of the short segment.

•Bezier curve

Max. Corner Size

This option replaces the road corner with a Bezier curve.

The max. corner size parameter sets the position of the Bezier curve for a given corner angle.

The smoothing curve never takes up more than half the length of a segment. So if the nominated max. corner size is too large (i.e. a segment is too short) the actual corner size is adjusted to occupy half of the short segment.

Sharpness

The shape of the curve (how far it extends into the corner) is determined by the Bezier sharpness parameter.

Useful range: about (0.2 to 2.0).

Larger values of this parameter lead to curves extending far into the corner (Bezier sharpness greater than about 1.0). Smaller values lead to curves which approach joining across the corner by a straight line (Bezier sharpness smaller than about 0.2).

End Height Page

Road segments are actually 3D straight lines.

The end height of each segment depends on the height of that segment's start point and the segment slope. The three parameters on this page always show the correct values for the current segment.

Three options are offered for determining the segment end height:

Constant Slope

In this option, the user inputs a segment slope. The correct values for the other two parameters are always calculated and displayed.

Constant Z

In this option, the segment end height is determined directly by an input parameter value. The correct values for the other two parameters are always calculated and displayed.

Terrain Z Offset

Here the segment end height is set to the terrain height at that point, with an added offset. This offset may be either positive or negative to give end heights above or below the terrain surface respectively. The correct values for the other two parameters are always calculated and displayed.