Symmetry

L3DD is very good at designing symmetrical objects, its symmetry elements having been adapted from the science of crystallography. The elements built into L3DD include a Center of Symmetry, 3 Mirror Planes and a multifunction Y Rotation Axis. These elements, which can be turned on and off at will, are a powerful means of replicating vertices and faces. Designing a spiral staircase, for example, becomes a trivial exercise with a Y rotation axis that increments the Y coordinates at each rotation step. The construction of a human head benefits greatly from the presence of a Y-Z mirror plane. Actions on the right side are immediately reproduced in mirror image on the left side. All symmetry commands can be accessed in the Symmetry Menu.

Real-Time Symmetry The symmetry elements in L3DD support both ‘real-time’ and ‘batch’ modes of operation. All newly created faces and vertices are instantly reflected across a mirror plane, or repeated ‘N’ times around an N-fold rotation axis. All selections using Shift-left mouse click are immediately reproduced by the current symmetry elements. On the other hand, you can replicate a completed object by turning on the appropriate symmetry elements and using the Apply Symmetry command.

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Symmetrical Movement When symmetry elements are present all movements of single vertices or faces are symmetrically reproduced. For example, when a 12-fold Y Rotation Axis is applied to the chalice from the ‘HoleyGrail.lig’ file, radial movement of just one vertex on the rim produces the result illustrated to the right. Similarly, with All Three Mirrors in place, movement of just one vertex of a cube moves all vertices simultaneously and makes the cube bigger or smaller

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Symmetrical Selection When one or more symmetry element is active, hold the Shift key down and click on a vertex or face with the left mouse button to invoke symmetrical selection of vertices and faces. The faces selected can then be moved as a group, deleted, or modified with one of L3DD’s tools, like Star Maker. Note that symmetrical movement does not apply to a group of faces or vertices. Group movement ignores symmetry.