TrueGrid® can use existing geometry from solids modelers and CAD/CAM systems via the IGES format, polygonal data, or scattered data. TrueGrid® also has an extensive geometry engine. The geometry from these different sources can be mixed in any way to form the required geometric model. For example, a smooth trimmed NURBS surface from a solids modeler can be combined with a non-smooth polygonal surface to form a single composite surface.
TrueGrid®'s Geometry Library Includes:
- Planes, spheres, cylinders, ellipsoids, cones, and tori
- 2D and 3D lines, polygonal curves, and arcs
- 2D and 3D cubic spline and NURBS curves
- 2D and 3D curves by algebraic functions
- 3D curves composed of edges of surfaces
- 3D curves from the intersection of surfaces
- Curves projected onto surfaces
- Concatenation of any set of 3D curves
- Curves of interpolation
- Lofted curves
- Surface edges and contours
- Surfaces of revolution
- Ruled, swept, and pipe surfaces
- Surfaces blended from 3 or 4 curves
- Cubic spline and NURBS surfaces
- Mesh and polygon surfaces including STL
- Combination of surfaces to form composites
- Surfaces by algebraic functions
- General transformations and normal offsets can be applied to the geometry
Polygon surfaces are typically used in the generation of biological meshes. There are vaious methods that extract data from MRI or CAT Scan data to form polygonal surface data. These surfaces can be modified, split, or composed in TrueGrid® to form the best representation of the biologic object.
The STLSD and the VPSD commands import a set of polygonal surfaces. One application of this is to comvert a surface or shell mesh to the VPSD format. Then a new multi-block structured high quality mesh can be built in TrueGrid® based on the outer faces of an existing mesh.
Polygon surfaces are similar to composite surfaces that may not be smooth. TrueGrid®'s projection and smoothing of the mesh works flawlessly on these non-smooth surfaces.