Editing ACIS (section)

== Functionality ==

=== ACIS Modeler ===
ACIS core functionality<ref name="acis_functionality">{{cite web | url=http://www.spatial.com/products/acis.html| title=ACIS Functionality | access-date=2007-03-16 |archive-url = https://web.archive.org/web/20070309194852/http://www.spatial.com/products/acis.html  |archive-date = 2007-03-09}}</ref> can be subclassified into three categories, namely:

==== 3D Modelling ====
* Extrude/revolve/sweep sets of 2D curves into complex surfaces or solids.
* Fillet and chamfer between faces and along edges in surface and solid models.
* Fit surfaces to a closed network of curves.
* Generate patterns of repetitive shapes.
* Hollow solids and thicken surfaces.
* Interactively bend, twist, stretch, and warp combinations of curves, surfaces, and solids.
* Intersect/subtract/unite any combination of curves, surfaces, and solids.
* Loft surfaces to fit a set of profile curves.
* Taper/offset/move surfaces in a model.

==== 3D Model Management ====

* Attach user-defined data to any level of a model.
* Track geometry and topology changes.
* Calculate mass and volume.
* Model sub-regions of a solid using cellular topology.
* Unlimited undo/redo with independent history streams.

==== 3D Model Visualization ====
* Tessellate surface geometry into polygonal mesh representation.
* Create advanced surfacing capabilities with the optional Deformable Modeling component.
* Generate precise 2D projections with hidden line removal using optional PHL V5 component.
* Develop graphical applications

=== ACIS Modeler Extensions ===
; CGM Polyhedra: CGM Polyhedra is an add-on to the 3D ACIS Modeler combining polyhedral and B-rep modeling. Utilizing the same interfaces that 3D ACIS Modeler users are already familiar with, existing and new customers can integrate approximated polyhedral data to their 3D printing, subtractive manufacturing, analysis, and other workflows.

; 3D Deformable Modeling: 3D Deformable Modeling is an interactive sculpting tool for shaping 3D models. Included as part of Spatial's suite of 3D modeling development technologies, 3D Deformable Modeling uses local and global editing features that allow for the creation and manipulation of free-form [[B-spline]] and [[NURBS]] curves and surfaces.

; Advanced Covering: Advanced Covering is a feature of Deformable Modeling that is now available as a standalone add-on for the 3D ACIS Modeler. This single API uses algorithms to create n-sided surfaces that meet user-specified tolerances for position and continuity on boundaries and on optional internal guiding geometry. Advanced Covering allows a surface to be fit onto circuits (collections of edges that form closed loops) in solid or wire bodies, which is useful in consumer product design. Among other uses, Advanced Covering can be used for end-capping, post-translation corrections, and surface definition from curve data.

; Defeaturing: Defeaturing automatically identifies and removes small features that computer aided engineering analysts typically want to eliminate from the 3D model prior to meshing. Analysts frequently work from the same models that are used for design and manufacture, but these models often carry much more detail than is necessary for [[simulation]] or analysis purposes. By removing unnecessary detail, defeaturing simplifies the model, a process that typically is done manually at significant cost.

; CGM HLR: CGM HLR is a hidden line removal (HLR) technology from Spatial based on [[CATIA]] V6 technology. CGM HLR is an ACIS-dependent development technology - an ACIS license is required.  Though 3D is now the de facto CAD standard in most engineering disciplines, 2D still has a place in industries such as technical illustration, [[manufacturing]], and [[architecture]]. Since 3D models are the typical primary output for CAD design, users in these industries require an efficient and accurate method of generating 2D computational drawings directly from the 3D models. Hidden line removal (HLR) is an important aspect of creating an accurate 2D representation from a 3D model. Using HLR, the converted model only displays those parts visible from a given perspective; hidden (or occluded) edges normally included in a 3D model representation are removed, or drawn in a line style that indicates their obscured position.