GEMS: Geometrical Exchange and Meshing Software

Entity Creation

Creation of points and lines:
• placement by graphical creation, relative to other geometry, and/or by giving one or more coordinate component explicitly (x,y,z,dx,dy,dz, distance along a direction, point of intersection, normal to a segment etc.);
• distribution of points along sections using a very wide choice of arc length based distribution types;
• by projection and intersection;
• by taking interactive "slices" through surface grids;

Creation of curves and wires
• Bezier and BSpline freeform creation; select, create and/or edit the control vertices;
• By point interpolation;
• Advanced Bezier/BSpline curve fitting: specify the tolerance, degree, number of Bezier segments and optionally start and end tangencies. This is a superb tool for the generation and smoothing of aerofoil sections from point data;
• From the isoparametric curves along surfaces;
• From surface trimming loops and edges;
• By projection of lines and curves onto surfaces;
• By advanced intersection of surfaces and/or planes. Using high-end CAD techniques, high quality intersections with fine tolerance control may be made between complex topological surfaces (connected or disconnected patch networks).

Creation of surfaces
• Bezier freeform creation;
• Ruled surfaces;
• Swept surfaces;
• Surfaces of revolution;
• Ferguson and C2 continuous bicubic surfaces by point interpolation;
• Advanced NURBS surface fitting given rectangular point data: specify tolerance, degrees in each parametric direction and optionally surface tangencies;
• Surface fitting to arbitrary point clusters. This uses an advanced algorithm based on the principle of the deformation of a plate by localised forces; the solution satisfies the constraints with minimum energy input;
• Powerful "repair" surfacing: creating a surface to fill a hole (specify any number of edge curves, respecting tangency)
• Surfaces by modification of existing surfaces (direct editing of control points, untrimming, and adding trimming loops).

Entity Modification

Transform any entity type:
• Translate
• Rotate
• Scale
• Stretch
• Reflect
• Build your own complex transform
• Freeform transforms and alignments

Entity and point projection:
• onto lines
• onto planes
• onto surfaces (normal to the surface or in a specified direction)

• Topological operations on curves and surfaces such as Cut and Fuse; connecting surface patches to form a shell, and curves to form a wire
• reorient surfaces, grids etc.
• reverse lines, curves etc.
• smoothly reprofiling section lines by performing a "NURBS Edit" - fitting a curve and editing the curve descriptor;
• smoothly recontouring a quadrilateral grid by fitting and editing a NURBS surface;
• trim and untrim surfaces, curves, lines
• projection: onto lines, planes, surfaces (normal or in a specified direction)
• split and merge

Entity management