Isolate Mechanism Overview

The “Isolate” mechanism allows you to isolate elements in a dome and determine their unique quanties. The mechanism works on either the underlying quad-edge manifold (Vertex, Edge, Face) or the mesh superimpositions (Hub, Strut, Panel). Unique elements are grouped into sets, labelled in the OpenGL view and printed in the Log, along with their respective properties. A set may be isolated in the OpenGL view by selecting its entry in the Isolate Popup. When you isolate a set, only that set is visible:

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IMPORTANT: Isolate sets are created by deciding which elements are considered equal in terms of their lengths, areas or angles between struts at a vertex. The precision settings that determine these equalities are of vital significance. Before Geodesica-SFX-0-9-9-6, setting the relevent precision for a set was done on the Precision tab in the Preferences window. As from Geodesica-SFX-0-9-9-6, precision settings can be changed for each Isolate set, and the fuzzy-logic equivalence settings are printed in the Log.

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Sometimes the reduction of a single decimal place can have significant results on the contents of an isolate set. Precision becomes more critical as the Frequency and/or Unit Radius Scale Factor is increased. The available digits of precision decreases as the Unit Radius Scale Factor increases.

ISOLATE TA Tab

The current Target is switched to A.
If the Primal tab is visible, the Pick Target is switched to Primal only (the 'P' button highlights yellow in the Toolbar whilst the 'D' and 'S' buttons are turned off.

If the Dual tab is visible, the Pick Target is switched to Dual only (the 'D' highlights yellow in the Toolbar whilst the 'P' and 'S' buttons are turned off.

ISOLATE TB Tab

The current Target is switched to B.
If the Primal tab is visible, the Pick Target is switched to Primal only (the 'P' button highlights yellow in the Toolbar whilst the 'D' and 'S' buttons are turned off.

If the Dual tab is visible, the Pick Target is switched to Dual only (the 'D' button highlights yellow in the Toolbar whilst the 'P' and 'S' buttons are turned off.

ISOLATE SF Tab

The current Target remains unchanged.
The Pick Target is switched to Spaceframe only (the 'S' button highlights yellow in the Toolbar whilst the 'P' and 'D' buttons are turned off.

The ISOLATE SF Tab has a menu choice to select the spaceframe node; the corresponding Isolate lists are then loaded into the Isolate pop-ups for Edges and Struts.

Creating an Isolate Set

  1. Select a Primal, Dual or Spaceframe tab.
  2. Set the Isolate Mode by clicking the button for the chosen element (eg Vertex, Edge or Face).
  3. As from Geodesica-SFX-0-9-9-6, the Isolate Set Precision dialogue appears. Set the precision for determing equality within the set.
  4. Follow the instructions in the STATUS BAR at bottom of the Main window. (E.g., click on an element in the manifold).
  5. The relevant Isolate pop-up menu activates with a list of Isolate sets. When you select an item from the pop-up, labels only appear for that set. In the case of FACE, STRUT, HUB and PANEL modes, only the selected set appears in the view with its respective labels, whilst other set elements are hidden.

Generating Isolate Set Colours

You can set colours for Isolate groups on the ‘Colours’ tab of the ‘Preferences’ window. This is documented here.

When analying vertices or hubs, it is possible to generate a full connectivity log which lists the unique hub sets, along with their connecting struts, as well their connecting hubs. This facilitates dome construction by providing all the necessary data to build even the most complex dome.