Reducing complexity and size: Simplify Bodies
Time to read: ~6 min
The Simplify Tool operates using one of three different algorithms/methods to gradually reduce the number of triangles in the body while attempting to
retain a shape that resembles the original as much as possible.
The main purpose for this tool is to allow files that were generated with excessive amounts of detail to be simplified
without losing the overall topology of the body being worked on. This is beneficial for cases where (for example) a human has been 3D scanned
and is to be placed in a CAD file for the purpose of determining a suitable fit or similar. In this case, only the overall shape is of
importance with sub-millimeter details around the face being (probably) of less concern.
The basic workflow for the tool is quite straight forward. Once the data has been loaded, it is up to the user to determine whether the data
consist of a single shape or should first be split up into different components (use the Split tool from the main tool bar for this). Splitting
the data, or at least attempting to do so, is generally recommended as the application will otherwise expect that all data is connected and will try
to enforce this. Even if the data looks to be a single shape, internal discontinuities may still remain. If the application determines that there
are no split-able bodies, no changes are made. Otherwise, different bodies will show up by being colored differently.
At this point, clicking the main Simplify button in the tool bar will switch the Options tab to the Simplify settings if not yet done. The sizing method can be chosen and
a relevant parameter provided. Under the Apply grouping, the option exists to apply the simplification to all bodies or just those selected in the viewer (if
applicable) as well as whether a Preview is first to be generated (recommended) or the data directly converted and applied.
Different reduction algorithms can be chosen from the Menu Bar: Settings>Application Settings>Simplify.
Settings / Algorithms
Different algorithms are implemented to allow slightly different behavior in the processing of data. This may be due to issues with the quality or size of the body
or for other reasons. Selection of the Algorithm is accomplished from the Application Settings under the Simplify
grouping (Menu>Settings>Application Settings>Simplify)
The original implementation from the InStep V2.x application is provided as the Legacy option. The new default is the g3_Reduce or alternatively the g3_Remesh_Reduce.
Both of these last two options use the geometry3Sharp library (open source, developed by gradientspace) but the Remesh_Reduce includes an additional step of first
performing a remeshing of the original data to provide a more uniform
starting point for cases with data integrity issues. This can be useful in cases where the data either comes directly from a point cloud or contains similar artifacts or one where the data
originates from a system that can generate slivers or similar shapes that otherwise bias the output in their favor (long cylinders with long, slender triangles
on their sides would thus benefit from this).