Part BooleanFragments/ru

Описание
Инструмент для вычисления всех фрагментов, которые могут возникнуть в результате применения логических операций между входными фигурами. Например, для двух пересекающихся сфер создаются три неперекрывающихся, но соприкасающихся твердых тела.



(на картинке выше части были впоследствии раздвинуты вручную, чтобы показать разрез)

Итоговая форма всегда является компаундом. Состав компаунда зависит от типов входных фигур и режима работы. Это означает, что вы не сразу получаете доступ к отдельным частям результата - части остаются сгруппированными вместе. Отдельные части могут быть извлечены путем применения разбивки соединения (Draft Downgrade).

The tool has three modes: "Standard", "Split", and "CompSolid".

"Standard" and "Split" differ by the action of the tool on wires, shells and compsolids: if "Split", those are separated; if "Standard", they are kept together (get extra segments).

Compounding structure in "Standard" and "Split" modes follows the compounding structure of inputs. That is, if you feed in two compounds, each containing a sphere like on example above, the result will also contain two compounds, each containing the pieces of the originally contained sphere. That means, the common piece will be repeated twice in the result. Only if the input spheres are both not in compounds, the result will contain the common piece once.

In "CompSolid" mode, the solids are joined into a compsolid (compsolid is a set of solids connected by faces; they are related to solids like wires are related to edges, and shells are related to faces; the name is probably a shortened phrase "composite solid"). The output is a non-nested compound of compsolids

Использование
The order of selection is not important, since the action of the tool is symmetric. It is enough to select one sub-shape of each object (e.g., faces). You can also select a compound containing all the shapes to be connected, e.g. Draft Array.
 * 1) Select objects to be intersected.
 * 1) Invoke the Part BooleanFragments command several ways:
 * 2) * Pressing the [[Image:Part_BooleanFragments.svg|24px|link=Part_BooleanFragments]] button in the toolbar
 * 3) * Using the entry in the Part menu

A Boolean Fragments parametric object is created. Original objects are hidden, and the result of intersection is shown in 3D view.

Свойства

 * : List of objects to be intersected. Generally, at least two objects are needed, but a single compound containing the shapes to intersect will do as well. (as of FreeCAD v0.17.8053, this property is not displayed in property editor, and can only be accessed via Python).
 * : "Standard", "Split", or "CompSolid". "Standard" is default. Standard and Split differ by the action of the tool on aggregation type shapes: if Split, those are separated; otherwise they are kept together (get extra segments).
 * : "fuzziness" value. This is an extra tolerance to apply when searching for intersections, in addition to tolerances stored in the input shapes.

Implementation details
Boolean Fragments tool in "Standard mode" is OpenCascade's General Fuse Operator (GFA). It accepts a combination of probably all shape types, and the logic of output is quite convoluted. See OpenCascade user guide: Boolean operations.

For "Split" and "CompSolid" modes, extra post-processing is done by FreeCAD.

Scripting
The tool can by used in macros and from the python console by using the following function: BOPTools.SplitFeatures.makeBooleanFragments(name)


 * Creates an empty BooleanFragments feature. The 'Objects' property must be assigned explicitly, afterwards.
 * Returns the newly created object.

BooleanFragments can also be applied to plain shapes, without the need to have a document object, via:

This can be useful for making custom Python scripted features.

Пример:

Инструмент сам реализован на Python, см. /Mod/Part/BOPTools/SplitFeatures.py там, где установлен FreeCAD.

Примечания
Инструмент появился в FreeCAD v0.17.8053. FreeCAD необходимо скомпилировать с OCC 6.9.0 или новее, иначе инструмент будет недоступен.