Component:Local Operations
From DocR23
Local Operations Component
The Local Operations component (LOP) provides a way to locally manipulate the geometry of a face or set of faces in a prescribed way while making limited changes to the topology of the solid model. Local Operations allows existing model features to be manipulated without the use of Boolean operations. The integrity of the model's topology and geometry remains intact as features are relocated or adjusted.
Local Operations can be used through a basic tweak operation (replacing the surface under a face) but has greater power through other operations, such as moving or offsetting. Unlike a tweak operation, which requires the user to input tool surface(s) for the replacement, these operations create the new surfaces for a face based on translation and offsetting algorithms.
Local Operations and its sister components (Shelling (SHL), Repair Body Intersection (RBI), and Remove Faces (REM)) all have a rich set of options that can be used to set error data and validation, order of operations, repair algorithms, and preferences for solutions.
Local Operations Operations
| Operation | Description |
|---|---|
| Tweak | Tweaks an array of faces (effectively a replace the surface under a face operation) by calculating new geometric definitions for each edge and vertex of the tweaked faces to maintain the original ACIS body. |
| Move | Moves a surface under a face by applying a transform to the face's original surface. Move includes sweep-more, where a face is transformed along a sweep path. |
| Body Offset | Offsets the surfaces of a BODY, given a specific distance(s), by computing an offset surface based on each surface's original definition. |
| Taper | Includes these types: plane taper, edge taper, and shadow taper. Tapers are primarily used for modifying dies or molds to allow the work piece to be removed easily, but are also of use in general modeling. |
| Sheetbody Extend | Extends the faces of a sheet body at the limiting edges by offsetting those edges to the specified offset distance. |
Local Operations Topics
Topology Changes in Local Operations
- Main article: Topology Changes in Local Operations
The Local Operations suite of functionality, including general TWEAK, move faces, taper faces, body offset, and shelling can produce a body with different topology.
Adaptive Offsetting
- Main article: Adaptive Offsetting
Local Operations supports Adaptive Offsetting; the ability to offset a surface to an approximation when limited by curvature and other constraints.
Limitations of Local Operations
- Main article: Limitations of Local Operations
Local Operations has the following limitations and behaviors.
Defeaturing
- Main article: Defeaturing
The ACIS Defeaturing Component supplies functionality that recognizes and/or removes "features" from an ACIS model.
Local Operations Interface
APIs
The C++ Local Operation APIs consist of a rich set of functions that support and perform the standard LOPs Operations. This suite of APIs generally work with a list of faces to be modified and the corresponding data needed for the particular operation (for example, vectors for the move operation and distances for the offset operations).
To improve performance, the APIs optionally take a 3D bounding box which specifies the extents in which the surface/surface and curve/surface intersections will be calculated. (Refer to Topology and Multiple Solutions in Local Operations.)
Functional Options
The Local Operations APIs accept a lop_options object. Several of these options existed as Global Options (below) in previous releases, however, they are now specified through functional options. Refer to the Global Options documentation for complete coverage.
Global Options
The main Local Operations APIs take options to control their behavior.
Important: For historical reasons, some global options also affect the behavior of Local Operations. Refer to Local Operations global options.
