The 3D ACIS® Modeler (ACIS) is Spatial’s prominent 3D solid modeling engine. 3D InterOp is a CAD data translation framework (Interoperability)
Component:ACIS Deformable Modeling
From DocR20
The 3D ACIS Deformable Modeling provides powerful low-level tools. The Advanced Covering Component provides a simple interface which packages a lot of Deformable Modeling functionality.
The Deformable Modeling Component is a powerful alternative to traditional surface modeling techniques such as control point manipulation and lofting. Control point manipulation can change a free-form shape interactively, but not while enforcing constraints. With lofting, you can build surfaces that satisfy several constraints, but it does not allow the sculpting of shapes. These time-consuming methods often result in surfaces with poor reflection lines and other undesirable qualities.
In contrast, 3D Deformable Modeling is intuitive, requiring less manipulation, time, and user knowledge while producing a higher-quality result.
The following sequence shows how Advanced Covering can be used to fill the missing region of a surface while maintaining both positional and tangential continuity even on geometrically complex faces.
 |
 |
Using an energy-based optimization strategy, 3D Deformable Modeling minimizes the energy stored due to bending and stretching. In this way, the shape that a deformable curve adopts is the one shape out of all possible shapes that minimizes the internal energy of the curve. This algorithm automatically produces fair shapes similar to those seen in the billowing of a sail or the clean line of a bending beam.
ACIS Deformable Modeling provides all of the basic tools needed to modify surfaces of ACIS solid or sheet bodies, or curves of ACIS wire bodies. The basic operations are:
- Construct a Deformable Model (curve or surface) from an ACIS model (wire or sheet/solid).
- Link together surface Deformable Models, if desired.
- Change material properties (resistance to bending and stretching).
- Apply loads over different domains (point, curve, area) with different behaviors (position, tangency, or curvature specification).
- Solve for curve or surface geometry which simultaneously satisfies the load and fairness conditions.
- Commit the resulting curve or surface(s) back into the ACIS model.
- Sculpting
- Deformation types
- Loads
- Conversion between Loads and Constraints
- Constraints
- Default Shapes
- Parameters
- Tag Objects
- Parametric Positions --A location on a curve or surface is identified by a parametric position specified by uv coordinates (surfaces) or u coordinates (curves). All deformable model curves and surfaces are parameterized on the unit square. That is, the parameter values always vary from 0 to 1 with the value of 0.5 being the middle. Any scaling required to map the deformable model parameterization to that of the internal deformable model parameterization is made by the deformable modeling package for the user.
- Interfaces
- Limitations
The ADM implementation is a C++ library. It comes with three user interfaces:
- C++ programmable interface consisting of API functions and a family of sculpting methods supported by the ATTRIB_DM2ACIS C++ object.
- Scheme interpreter interface consisting of a set of Scheme extensions that expose the API functions and ADM methods to the Scheme interpreter.
- Example mouse interface for interactive sculpting consisting of a set of Scheme files which build an ADM rubberband capability.
For more information, refer to Deformable Modeling Interfaces.
