In solid modeling and computer-aided design, boundary representation—often abbreviated as B-rep or BREP—is a method for representing shapes using the limits. A solid is represented as a collection of connected surface elements, the boundary between solid and non-solid. Boundary representation of models are composed of two parts: topology and geometry surfaces, curves and points.
The main topological items are: faces, edges and vertices. A face is a bounded portion of a surface; an edge is a bounded piece of a curve and a vertex lies at a point.
Other elements are the shell a set of connected faces , the loop a circuit of edges bounding a face and loop-edge links also known as winged edge links or half-edges which are used to create the edge circuits. The edges are like the edges of a table, bounding a surface portion. Compared to the constructive solid geometry CSG representation, which uses only primitive objects and Boolean operations to combine them, boundary representation is more flexible and has a much richer operation set.
Curves2D Property. Curves3D Property. Edges Property. Faces Property. IsManifold Property. IsSolid Property. IsSurface Property. Loops Property. SolidOrientation Property. Surfaces Property. Trims Property. Rajaa Isaa McNeel Assc. Polysurfaces and trimmed surfaces are represented using what is called boundary representation brep for short.
It basically describes surface, edge, and vertex geometry with trimming data and relationships among different parts. For example, the brep describes each face, its surrounding edges and trims, normal direction relative to the surface, relationship with neighboring faces and so on.
Breps can also be called solids when they are closed or watertight. There are tools that are provided by the 3D NURBS modelers to edit or deform polysurfaces directly such as the Box Morphing technique that was posted in previous tutorial, but it is also common to explode a polysurface to its component surfaces, edit those, and play around with it.
Sweep1 function that fits a surface through a profile curve that define the surface cross-sections and one curve that defines a surface edge. Sweep1 function that fits a surface through profile curves that define the surface cross-sections and one curve that defines a surface edge.
General 2 rail sweep. If you are not producing the sweep results that you are after, then use the SweepTwoRail class with options to generate the swept geometry.
Sweep2 function that fits a surface through profile curves that define the surface cross-sections and two curves that defines the surface edges. Sweep1 function that fits a surface through a series of profile curves that define the surface cross-sections and one curve that defines a surface edge. Makes a 2 rail sweep. Like CreateFromSweep but the result is split where parameterization along a rail changes abruptly. The Segmented version breaks the rail at curvature kinks and sweeps each piece separately, then put the results together into a Brep.
Extrude a curve to a taper making a brep potentially more than 1. Creates one or more Breps by extruding a curve a distance along an axis with draft angle. Constructs a brep patch. This is the simple version of fit that uses a specified starting surface. Creates a hollowed out shell from a solid Brep. Function only operates on simple, solid, manifold Breps.
Constructs closed polysurfaces from surfaces and polysurfaces that bound a region in space. Constructs a Brep using the trimming information of a brep face and a surface. Surface must be roughly the same shape and in the same location as the trimming brep face.
Same as Duplicate , but already performs a cast to a brep. This cast always succeeds. Constructs a light copy of this object. By "light", it is meant that the same underlying data is used until something is done to attempt to change it.
For example, you could have a shallow copy of a very heavy mesh object and the same underlying data will be used when doing things like inspecting the number of faces on the mesh. If you modify the location of one of the mesh vertices, the shallow copy will create a full duplicate of the underlying mesh data and the shallow copy will become a deep copy. If you want to keep a copy of this class around by holding onto it in a variable after a command completes, call EnsurePrivateCopy to make sure that this class is not tied to the document.
You can call this function as many times as you want. Passively reclaims unmanaged resources when the class user did not explicitly call Dispose. Find the indices of all brep faces, edges and vertices that are within tolerance of a test-point. Compute the Area of the Brep. If you want proper Area data with moments and error information, use the AreaMassProperties class. Bounding box solver. Gets the world axis aligned bounding box for the geometry.
Aligned Bounding box solver. Gets the world axis aligned bounding box for the transformed geometry. Populates a System. SerializationInfo with the data needed to serialize the target object. Gets the Type of the current instance. Gets a copy of all user key string, user value string pairs attached to this geometry.
Compute the Volume of the Brep. If you want proper Volume data with moments and error information, use the VolumeMassProperties class. Determines if point is inside a Brep. This question only makes sense when the brep is a closed and manifold. This function does not check for closed or manifold, so result is not valid in those cases.
Intersects a line through point with brep, finds the intersection point Q closest to point, and looks at face normal at Q. If the point Q is on an edge or the intersection is not transverse at Q, then another line is used. Expert user function that tests the brep to see if its geometry information is valid. The value of brep. IsValidTopology must be true before brep. IsValidGeometry can be safely called. Expert user function that tests the brep to see if its tolerances and flags are valid.
The values of brep. IsValidTopology and brep. IsValidGeometry must be true before brep. IsValidTolerancesAndFlags can be safely called. Determines if an object is valid. Also provides a report on errors if this object happens not to be valid. If any edges of this brep overlap edges of otherBrep, merge a copy of otherBrep into this brep joining all edges that overlap within tolerance. Joins the breps in the input array at any overlapping edges to form as few as possible resulting breps.
There may be more than one brep in the result array. Joins two naked edges, or edges that are coincident or close together. Joins naked edge pairs within the same brep that overlap within tolerance. If possible, converts the object into a form that can be accurately modified with "squishy" transformations like projections, shears, an non-uniform scaling.
No support is available for this function. Creates a shallow copy of the current Object. Computes an estimate of the number of bytes that this object is using in memory.
Combines two or more breps into one. A merge is like a boolean union that keeps the inside pieces. This function creates non-manifold Breps which in general are unusual in Rhino. Merges two surfaces into one surface at untrimmed edges. Both surfaces must be untrimmed and share an edge. Recursively removes any Brep face with a naked edge. This function is only useful for non-manifold Breps. Fills in missing or fixes incorrect component information from a Brep.
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