Component:ACIS Deformable Modeling
From DocR21
ACIS Deformable Modeling provides powerful, low-level tools to create and manipulate freeform B-spline curves and surfaces. The Advanced Covering Component provides a simplified interface to much of the Deformable Modeling functionality.
ACIS Deformable Modeling 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, ACIS Deformable Modeling is intuitive, requiring less manipulation, time, and user knowledge while producing a higher-quality result.
The following sequence shows how Advanced Covering or Deformable Modeling can be used to fill the missing region of a surface while maintaining both positional and tangential continuity even on geometrically complex faces.
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Using an energy-based optimization strategy, ACIS Deformable Modeling minimizes the energy stored due to bending and stretching. In this way the shape that a deformable curve or surface adopts is the one shape out of all possible shapes that minimizes the internal energy of the curve or surface. 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.
- Attach 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 smoothness conditions.
- Commit the resulting curve or surface(s) back into the ACIS model.
The ACIS Deformable Modeling (ADM) has three interfaces:
- C++ programmable interface consists of API functions and a family of sculpting methods supported by ATTRIB_DM2ACIS objects.
- Scheme interpreter interface consists of a set of Scheme Extensions that expose the API functions and ADM methods through the Scheme AIDE.
- Example mouse interface for interactive sculpting, consists of a set of Scheme files that build an ADM rubberband capability.
For more information, refer to Deformable Modeling Interfaces.
