Excavation Settings

This dialog box provides context sensitive help.

The Excavation Settings Dialog box allows users to control how the program excavates a surface. This is done by:

•Altering the way in which Excavation Polygons are created.

•Altering the way in which Master Polygons are created.

•Applying Excavation Constraints while excavating.

Polygon creation and excavation methods are described in the Terrain Excavation topic.

Excavation Settings and polygons are grouped together in an Excavation Template. A number of such excavation templates may be created for each excavated surface. One of these excavation templates is nominated as active.

The following is a description of the items in the Excavation Settings dialog box.

Items in the Excavation Settings Dialog Box

Name of Excavated Surface

This is the name of the surface that is to be excavated. Excavation Settings parameters are individual to each surface.

The Excavated Surface will usually be the Terrain Surface. However inner surfaces may also be excavated. This offers a convenient way to change the shape of an inner surface.

Active Excavation Template

This is the name of the excavation template used to excavate the Excavated Surface. Additional excavation templates associated with the current surface may be created by pressing the New button. Then the user may select which excavation template to set as active.

Each excavation template consists of the item and settings in this dialog box, together with a pair of excavation polygons, the inner and outer excavation polygons. These polygons do not exist until they are drawn or otherwise created by the user.

General Log

The volume of excavated material is calculated after each excavation. This material is logged to the nominated general log. Bank volume, swelled volume and mass are all calculated and logged to the specified general log.

A general log is associated with each excavation template i.e. it applies to all excavation events carried out with this template. A different general log may be selected here from the list of existing general log. New general logs are created in the Logged Material dialog box (Material/Logged information menu).

New Button

The New button is used to create a new excavation template for the current excavated surface. The new excavation template automatically becomes active.

Delete Button

The Delete button deletes the active excavation template for the current excavated surface.

Save Button

The Save button is used to store all settings for the current excavated surface. If the selected surface or active excavation template is changed with some altered settings unsaved, users will be given the option to save altered settings.

Close Button

The Close button closes the Excavation Settings dialog box. If some settings for the current excavation template are unsaved, users will be given the option to save altered settings.

Excavation Constraints Page

Excavation constraints limit the excavation in various ways.

Current Master Polygons

Master Polygons limit the excavation.

The user may specify and store several pairs of Master Polygons associated with each excavation and surface. However only the Current Master Polygons are taken into account when excavating (if the Apply Master Polygons option is enabled).

Each item in this list represents a master polygon pair i.e. an inner and outer polygon. The polygons do not exist until they are drawn or otherwise created by the user.

This option allows the user to select Current Master Polygons.

Excavate Only

When the excavate only option is enabled, no fill is ever placed on the terrain. In areas where the inner polygon is above the excavated surface, the surface is left unchanged.

Fill Only

When the fill only option is enabled, no material is ever removed from the terrain. In areas where the inner polygon is below the excavated surface, the surface is left unchanged.

Excavate Layers Only

Excavate layers only, do not excavate terrain.

Apply Master Polygons

Master Polygons limit the excavation. Think of it in this way:

Imagine excavating using the Master Polygons instead of Excavation Polygons. This new surface formed in this way is the final limit. It is impossible to excavate any further than this surface when the Apply Master Polygons option is enabled.

Master Polygons thus provide a convenient way of setting up a final excavation limit. This reduces the need to be so precise with placement of Excavation Polygons on each excavation near a final limit.

Partial Excavation

This setting controls the amount of material excavated or filled.

A setting of 100% means that all of the material destined for excavation or filling will be excavated or filled.

A lower setting means that only the indicated percentage of material is processed, with some material left unprocessed.

The material is excavated or filled proportionally over the excavated region, so that the same fraction of material is processed at each point.

Limit by Surface

This setting restricts the excavation process so as not to extend beyond a nominated surface. If the excavation polygon is below the excavated surface (excavation), the limit by surface command will not allow the excavation to extend below the limiting surface. If the excavation polygon is above the excavated surface (fill), the limit by surface command will not allow fill to extend above the limiting surface.

Apply to Excavate

This setting applies the Limit Surface constraint to excavation only.

Apply to Fill

This setting applies the Limit Surface constraint to fill only.

Clip Excavation to Surface Boundary

Set this flag to confine excavation or fill to the common limit surface outline. Otherwise surface may be excavated or filled outside the outlines of the limit surfaces.

Turn All Excavate Layers ON Button

Turn On Excavate Layer flag in all Layers.

Turn All Excavate Layers OFF Button

Turn Off Excavate Layer flag in all Layers.

New Button

The New button is used to add a new item to the list of master polygon pairs associated with the active excavation for the current excavated surface.

Delete Button

The Delete button removes an item from the list of master polygon pairs associated with the active excavation for the current excavated surface.

Check Logged Layers for Overlap

Check logged layers for overlap on excavation.

Select for Draw/Generate

This setting specifies which kind of polygons (Excavation or Master) will be created when drawing/generating polygons. Polygons are drawn using the Excavate/Fill menu items or appropriate toolbar buttons. Generate calculates polygons using an outer from inner or inner from outer calculation.

Excavation/Master Polygon Page

These pages allow user to specify parameters of excavation/master polygons and contain two subpages - Properties and Battering.

Properties Page

The Properties page allows users to set the properties of excavation/master polygons. These properties are:

•The method of setting the inner polygon vertex heights.

•Whether automatic polygon generation using batter angles is outer from inner or inner from outer.

•Whether both the inner and outer excavation polygons are to be deleted after 100% excavation.

Polygon Creation Mode

This item allows users to choose how the second polygon in an Excavation or Master polygon pair is to be generated.

Outer from Inner

If an inner polygon exists together with its batter angles, then the corresponding outer polygon can be automatically generated in outer from inner mode.

Inner from Outer

If an outer polygon exists together with its batter angles, then the corresponding inner polygon can be automatically generated in inner from outer mode.

Both polygons can be independently drawn by the user in either mode.

Inner Polygon Heights

This item refers to the method of setting heights along the inner polygon. Heights are set only for the inner polygon. The outer polygon is draped on the surface to be excavated. Hence outer polygon heights are not set by the user.

Individual Vertex Heights

Here each vertex of the inner polygon is assigned its own individual height. Heights of intermediate points are calculated from the vertex heights by linear interpolation.

Common Vertex Height

Here all vertices of the inner polygon are at a single height. Thus the whole polygon has one common z coordinate.

Bind to Surface

Here the inner polygon is draped on an inner surface. Each point along the polygon then receives its height from this surface. The polygon may be offset from this surface by a constant height, using the offset from surface parameter. A negative offset indicates that the polygon is located below the nominated surface.

This is a convenient way to excavate to a fixed depth below the excavated surface: bind to the excavated surface and then offset by a negative amount.

Delete after Full Excavation

This option is present only on Excavation Polygon page. If the option is enabled, both inner and outer excavation polygons are deleted after a 100% excavation. Partial excavation (less than 100% of material removed) will leave the polygons in place.

Battering Page

Polygon battering is the process of generating an outer polygon from an inner polygon (outer from inner mode), or an inner polygon from an outer polygon (inner from outer mode). This process uses batter angles defined around the source polygon.

Segment Connection Type

Segments of a generated polygon will likely be disconnected. Such segments need to be connected. Three methods are offered for connecting such segments, as below.

1. Parallel Projection

In this option the end of each generated polygon’s disconnected segment is projected along the surface, parallel to the source segment in plan view. These projected segments cross to connect the disconnected segments.

Paral1

2. Batter Angle Transition

In this option two disconnected generated polygon segments are connected by using intermediate batter angles to form the batter angle transition zone. These batter angles "fan out" from the junction of the two source segments.

Batter1

3. Bezier Curve

In this option two disconnected generated polygon segments are connected by a Bezier curve. This curve is inscribed in the angle formed by three points: the ends of the two segments, and the point obtained by parallel projection. The shape of this curve is controlled by the Bezier sharpness parameter.

Bezier1

Bezier Sharpness Parameter

This parameter controls the sharpness of the Bezier curve used to connect two disconnected generated polygon segments. Larger values of this parameter lead to sharper curve shapes.

Average Angle Step

The number of points (i.e. extra polygon segments) in the transition region which connects two disconnected generated polygon segments is controlled by the average angle step. Larger values of the step parameter lead to fewer transition segments.