Drawing a Sector¶
To add a Sector, click the second (round) button in the Layer Manager’s top bar. This will present a controller where the following parameters can be adjusted:
A helpful name should be entered here to allow for easy recognition of the layer within the sources list. There are times when the name will have prefixes or suffixes appended, depending on how the layer was created:
- Columns vs Rows
With regards to the data entry boxes at the top of the controller, these are arranged in rows and columns. The left column of data pertains to the ‘start’ edge coordinates of the layer. The right column pertains to the ‘end’ edge coordinates of the layer. Data from this ‘end’ edge is used when continuing a layer. The rows from top to bottom perform the action of the label to their left.
- Interdependence of Range & Angle vs Depth & Height
All of the parameters within the data table on the layer controller can be described in either angular or cartesian terms. This is to say that when constructing a layer, the start and end coordinates can either be described as radius and height (cartesian), or as range and angle (angular). The application automatically converts between angular and cartesian continuously; that is to say that when a radius and height is entered, the range and angle are automatically computed & vice versa.
- Start/End Radius
The start & end radius of the sector defines the length of the radius described by the origin of the front arc to the origin. In its initial state, with no transformations applied, the start radius controls the length of the radius of the layer closest to the Y-Axis origin along its normal, while the end radius controls the radius of the layer furthest away from the Y-Axis origin along its normal.
- Start/End Height
With no transformations applied, the start height controls the distance of the start arc from the Z-Axis origin, whilst the end height controls the distance of the end arc from the Z-Axis Origin.
- Start/End Range
With no transformations applied, the start range parameter defines the absolute shortest path from the origin to the centre of the start arc of the layer. The end range parameter defines the absolute shortest path from the origin to the centre of the end arc of the layer. These values are equivalent to the distance that would be read from a laser rangefinder.
- Start/End Angle
With no transformations applied, the start angle parameter defines the angle of the centre of the start arc of the layer from the origin. The end angle parameter defines the angle of the centre of the end arc of the layer from the origin. These values are equivalent to the inclinometer angle that would be read from a laser rangefinder.
- Opening Angle
The opening angle defines the arc angle of the layer. With it set to 180º, a semicircle is drawn. With it set to 360º, a circle is drawn.
- Rotation Angle
The rotation angle defines how the whole layer is rotated about the origin.
A colour picker is shown. Clicking and dragging the mouse pointer around this will set adjust the tint of the base plane. There are two sliders below the colour picker which adjust hue and alpha (transparency).
- Ear Height