Rhino.Geometrynamespace

The Geometry namespace contains geometric types used in Rhino.

Examples are lines, curves, meshes and boundary representations.

Types

Rhino.Geometry.AngularDimension
Represents a dimension of an entity that can be measured with an angle.
Rhino.Geometry.AnnotationBase
Provides a common base class to all annotation geometry.

This class refers to the geometric element that is independent from the document.

Rhino.Geometry.AnnotationType
ON::AnnotationType identifies the type of an annotation object derived from ON_Annotation.
Rhino.Geometry.Arc
Represents the value of a plane, two angles and a radius in a sub-curve of a three-dimensional circle.

The curve is parameterized by an angle expressed in radians. For an IsValid arc the total subtended angle AngleRadians() = Domain()(1) - Domain()(0) must satisfy 0 < AngleRadians() < 2*Pi

The parameterization of the Arc is inherited from the Circle it is derived from. In particular

t -> center + cos(t)*radius*xaxis + sin(t)*radius*yaxis

where xaxis and yaxis, (part of Circle.Plane) form an orthonormal frame of the plane containing the circle.

Rhino.Geometry.ArcCurve
Represent arcs and circles.

ArcCurve.IsCircle returns true if the curve is a complete circle.

Rhino.Geometry.AreaMassProperties
Contains static initialization methods and allows access to the computed metrics of area, area centroid and area moments in closed planar curves, in meshes, in surfaces, in hatches and in boundary representations.
Rhino.Geometry.Arrowhead
Arrowhead used by annotation
Rhino.Geometry.BezierCurve
Represents a Bezier curve.

Note: as an exception, the bezier curve is not derived from Curve.

Rhino.Geometry.BezierSurface
Represents a Bezier surface.

BlendContinuity

Since v5.0
Rhino.Geometry.BlendContinuity
Used in curve and surface blending and matching functions.

BlendType

Since v6.0
Rhino.Geometry.BlendType
Blend types used for creating filleted Brep edges
Rhino.Geometry.BoundingBox
Represents the value of two points in a bounding box defined by the two extreme corner points.

This box is therefore aligned to the world X, Y and Z axes.

Rhino.Geometry.Box
Represents the value of a plane and three intervals in an orthogonal, oriented box that is not necessarily parallel to the world Y, X, Z axes.
Rhino.Geometry.Brep
/// Boundary Representation. A surface or polysurface along with trim curve information.
Rhino.Geometry.Brep.CurveConstraint
Variational curve constraint (position)
Rhino.Geometry.Brep.FilletSurfaceResults
Results from a fillet surface operation
Rhino.Geometry.Brep.FilletSurfaceSettings
Settings to use when creating fillets or chamfers
Rhino.Geometry.Brep.PointConstraint
Constrain the result to go through a point
Rhino.Geometry.Brep.VariationalPatchResult
This result contains additional information about the patch generation: warnings and errors and the continuity achieved.
Rhino.Geometry.Brep.VariationalPatchSettings
Settings for the variational patch creation
Rhino.Geometry.BrepEdge
Represents a single edge curve in a Brep object.
Rhino.Geometry.BrepEdgeFilletDistance
Fillet distances along a BrepEdge
Rhino.Geometry.BrepFace
Provides strongly-typed access to brep faces.

A Brep face is composed of one surface and trimming curves.

Rhino.Geometry.BrepFace.ShrinkDisableSide
Defines bitwise mask flags indicating what side of a surface to not shrink.
Rhino.Geometry.BrepLoop
Represent a single loop in a Brep object. A loop is composed of a list of trim curves.

BrepLoopType

Since v5.0
Rhino.Geometry.BrepLoopType
Each brep loop has a defined type, e.g. outer, inner or point on surface.
Rhino.Geometry.BrepRegion
Represents a brep topological region that has sides.
Rhino.Geometry.BrepRegionFaceSide
Represents a side of a BrepRegion entity.
Rhino.Geometry.BrepReplaceEdgeMethod
How a deleted edge is re-trimmed by Brep.ReplaceEdge(IEnumerable<int>, BrepReplaceEdgeMethod, Curve, double). Equivalent to the options of the ReplaceEdge command.
Rhino.Geometry.BrepSolidOrientation
Enumerates all possible Solid Orientations for a Brep.
Rhino.Geometry.BrepTrim
Brep trim information is stored in BrepTrim classes. Brep.Trims is an array of all the trims in the brep. A BrepTrim is derived from CurveProxy so the trim can supply easy to use evaluation tools via the Curve virtual member functions. Note well that the domains and orientations of the curve m_C2[trim.m_c2i] and the trim as a curve may not agree.

BrepTrimType

Since v5.1
Rhino.Geometry.BrepTrimType
Each brep trim has a defined type.
Rhino.Geometry.BrepVertex
Brep vertex information
Rhino.Geometry.Centermark
Represents a center mark dimension.
Rhino.Geometry.ChainDirection
Which way to search along a chain from the current link.
Rhino.Geometry.Circle
Represents a circle in 3D.

The values used are a radius and an orthonormal frame of the plane containing the circle, with origin at the center.

The circle is parameterized by radians from 0 to 2 Pi given by

t -> center + cos(t)*radius*xaxis + sin(t)*radius*yaxis

where center, xaxis and yaxis define the orthonormal frame of the circle plane.

Rhino.Geometry.ClippingPlaneSurface
Represents a planar surface that is used as clipping plane in viewports. A clipping plane object maintains a list of viewports that it clips against.
Rhino.Geometry.ComponentIndex
Represents an index of an element contained in another object.
Rhino.Geometry.ComponentIndexType
Defines enumerated values to represent component index types.
Rhino.Geometry.ComponentStatus
Provides information about selection, highlighting, visibility, editability and integrity states of a component.

This structure is immutable.

Concavity

Since v6.2
Rhino.Geometry.Concavity
Enumerates the possible types of edge concavity types.
Rhino.Geometry.Cone
Represents the center plane, radius and height values in a right circular cone.
Rhino.Geometry.ConicSectionType
Defines enumerated values for types of conic sections.

Continuity

Since v5.0
Rhino.Geometry.Continuity
Provides enumerated values for continuity along geometry, such as continuous first derivative or continuous unit tangent and curvature.
Rhino.Geometry.ControlPoint
Represents control point geometry with three-dimensional position and weight.

CurvatureStyle

Since v9.0
Rhino.Geometry.CurvatureStyle
Curvature style
Rhino.Geometry.Curve
Represents a base class that is common to most RhinoCommon curve types.

A curve represents an entity that can be all visited by providing a single parameter, usually called t.

Rhino.Geometry.Curve.SortedSegment
A segment in a sorted curve collection
Rhino.Geometry.CurveBooleanRegions
Represents the results of a Curve.CreateBooleanRegions calculation.

CurveEnd

Since v5.0
Rhino.Geometry.CurveEnd
Defines the extremes of a curve through a flagged enumeration.
Rhino.Geometry.CurveEvaluationSide
Defines enumerated values for the options that defines a curve evaluation side when evaluating kinks.
Rhino.Geometry.CurveExtensionStyle
Defines enumerated values for styles to use during curve extension, such as "Line", "Arc" or "Smooth".
Rhino.Geometry.CurveKinkDefinition
A "kink" in a curve is a unit tangent discontinuity or a vector curvature discontinuity. This class is used to determine which types and magnitudes of unit tangent discontinuities and vector curvature discontinuities should are a "kink." It also provides functions for determining if there is a kink at a specific curve parameter.

CurveKnotStyle

Since v5.0
Rhino.Geometry.CurveKnotStyle
Defines enumerated values for knot spacing styles in interpolated curves.
Rhino.Geometry.CurveOffsetCornerStyle
Defines enumerated values for all implemented corner styles in curve offsets.
Rhino.Geometry.CurveOffsetEndStyle
Defines enumerated values for all implemented end styles in curve offsets.
Rhino.Geometry.CurveOrientation
Defines enumerated values for closed curve orientations.
Rhino.Geometry.CurveProxy
Represent curve geometry. Usually this is part of another piece of geometry that can be represented as a "proxy".
Rhino.Geometry.CurveSimplifyOptions
Enumerates the options to use when simplifying a curve.
Rhino.Geometry.Cylinder
Represents the values of a plane, a radius and two heights -on top and beneath- that define a right circular cylinder.
Rhino.Geometry.DetailView
Represents a view of the model placed on a page layout.
Rhino.Geometry.DevelopableSrf
Helpers for developable surface functions
Rhino.Geometry.Dimension
Base class for dimensions
Rhino.Geometry.Dimension.ForceArrow
OBSOLETE enum do not use.
Rhino.Geometry.Dimension.ForceText
OBSOLETE enum do not use.

DistancingMode

Since v6.0
Rhino.Geometry.DistancingMode
Defines how offset and similar operations should work.

EdgeAdjacency

Since v5.0
Rhino.Geometry.EdgeAdjacency
Enumerates all possible Topological Edge adjacency types.
Rhino.Geometry.Ellipse
Represents the values of a plane and the two semi-axes radii in an ellipse.
Rhino.Geometry.ExtrudeCornerType
Corner types used for creating a tapered extrusion
Rhino.Geometry.Extrusion
Represents an extrusion, or objects such as beams or linearly extruded elements, that can be represented by profile curves and two miter planes at the extremes.
Rhino.Geometry.FilletSurfaceSplitType
RhinoFilletSurfaceSplitType
Rhino.Geometry.GeometryBase
Provides a common base for most geometric classes. This class is abstract.
Rhino.Geometry.Hatch
Represents a hatch in planar boundary loop or loops. This is a 2d entity with a plane defining a local coordinate system. The loops, patterns, angles, etc are all in this local coordinate system. The Hatch object manages the plane and loop array Fill definitions are in the HatchPattern or class derived from HatchPattern Hatch has an index to get the pattern definition from the pattern table.
Rhino.Geometry.HermiteSurface
Create an ON_NurbsSurface satisfying Hermite interpolation conditions at a grid of points.
Rhino.Geometry.HiddenLineDrawing
Represents a hidden line drawing object. A hidden line drawing consists of curves generated from source objects. The curves correspond to edges, and silhouettes of source objects and intersections with cutting planes.
Rhino.Geometry.HiddenLineDrawingObject
Represents an object added to a HiddenLineDrawing
Rhino.Geometry.HiddenLineDrawingObjectCurve
Curves generated from source objects which correspond to edges, and silhouettes of source objects and intersections with cutting planes. A HiddenLineDrawingObjectCurve is partitioned into hidden and visible segments called HiddenLineDrawingSegment
Rhino.Geometry.HiddenLineDrawingParameters
Input used for computing a hidden line drawing
Rhino.Geometry.HiddenLineDrawingPoint
Points generated from source objects which correspond to point and point cloud source objects.
Rhino.Geometry.HiddenLineDrawingPoint.Visibility
The different types of HiddenLineObjectPoint visibility
Rhino.Geometry.HiddenLineDrawingSegment
The results of HiddenLineDrawing calculation are a collection of segments. A segment is a sub-curve of a HiddenLineDrawingObjectCurve.
Rhino.Geometry.HiddenLineDrawingSegment.SideFill
When a silhouette is projected on the image plane (determined by the camera location or direction), and projects to a curve (not a point), the image area to the left or right of a projected silhouette curve is filled with either the surface or a void.
Rhino.Geometry.HiddenLineDrawingSegment.Visibility
The different types of HiddenLineDrawingSegment visibility
Rhino.Geometry.InstanceDefinitionGeometry
Represents a block definition in a File3dm. This is the same as Rhino.DocObjects.InstanceDefinition, but not associated with a RhinoDoc.
Rhino.Geometry.InstanceReferenceGeometry
Represents a reference to the geometry in a block definition.
Rhino.Geometry.Interpolator
Exposes a set of standard numeric interpolation algorithms.
Rhino.Geometry.Interval
Represents an interval in one-dimensional space, that is defined as two extrema or bounds.
Rhino.Geometry.InvalidDimensionStyleIdException
General exception that can be thrown by annotations

IsoStatus

Since v5.0
Rhino.Geometry.IsoStatus
Defines enumerated values for isoparametric curve direction on a surface, such as X or Y, and curve sides, such as North or West boundary.

Note: odd values are all x-constant; even values > 0 are all y-constant.

KnotStyle

Since v7.0
Rhino.Geometry.KnotStyle
Knot styles for NURBS curves and surfaces. If a knot vector meets the conditions of two styles, then the style with the lowest value is used.
Rhino.Geometry.Leader
Leader geometry class
Rhino.Geometry.LengthMassProperties
Contains static initialization methods and allows access to the computed metrics of length, length centroid, and length moments in curves.
Rhino.Geometry.Light
Represents a light that shines in the modeling space.
Rhino.Geometry.Light.Attenuation
Types of light attenuation available.

LightStyle

Since v5.0
Rhino.Geometry.LightStyle
Defines enumerated values to represent light styles or types, such as directional or spotlight.
Rhino.Geometry.Line
Represents the value of start and end points in a single line segment.
Rhino.Geometry.LinearDimension
Represents a linear dimension
Rhino.Geometry.LineCurve
Represents a linear curve.

LoftType

Since v5.0
Rhino.Geometry.LoftType
Specifies enumerated constants for all supported loft types.
Rhino.Geometry.MatchSrfSettings
Settings for matching a surface edge to other edge(s)
Rhino.Geometry.Matrix
Represents an arbitrarily sized matrix of double-precision floating point numbers. If you are working with a 4x4 matrix, then you may want to use the Transform class instead.
Rhino.Geometry.Mesh
Represents a geometry type that is defined by vertices and faces.

This is often called a face-vertex mesh.

Rhino.Geometry.MeshBooleanOptions
Contains a set of data to pass to boolean options.
Rhino.Geometry.MeshCheckParameters
Output of a mesh checking operations.
Rhino.Geometry.MeshCurvatureStats
Analysis mesh curvature statistics.
Rhino.Geometry.MeshDisplacementInfo
Contains mesh displacement information.
Rhino.Geometry.MeshExtruder
Extrudes a mesh and provides preview
Rhino.Geometry.MeshExtruderFaceDirectionMode
Defines how mesh extruder decides orients faces
Rhino.Geometry.MeshExtruderParameterMode
Parameter mode for creating texture coordinates and surface parameters
Rhino.Geometry.MeshFace
Represents the values of the four indices of a mesh face quad.

If the third and fourth values are the same, this face represents a triangle.

Rhino.Geometry.MeshingParameters
Represents settings used for creating a mesh representation of a brep or surface.
Rhino.Geometry.MeshingParameterStyle
Type of Mesh Parameters used by the RhinoDoc for meshing objects
Rhino.Geometry.MeshingParameterTextureRange
Defines how to pack render/meshes textures.
Rhino.Geometry.MeshNgon
Represents a mesh ngon.

When retrieved from the Ngon property of a mesh, this contains faces that have edge valence strictly higher than 4.

When retrieving Ngons from Mesh.GetNgonAndFacesEnumerable(), this might contain also triangles and quads.

Rhino.Geometry.MeshPart
Represents a portion of a mesh for partitioning
Rhino.Geometry.MeshPipeCapStyle
Enumerates methods to end a mesh pipe.
Rhino.Geometry.MeshPoint
Represents a point that is found on a mesh.
Rhino.Geometry.MeshSplitOptions
Contains a set of data to pass to mesh splitting operations.
Rhino.Geometry.MeshThicknessMeasurement
Thickness measurement used in the mesh thickness solver.

MeshType

Since v5.0
Rhino.Geometry.MeshType
Defines enumerated values for various mesh types.
Rhino.Geometry.MeshUnsafeLock
Permits access to the underlying mesh raw data structures in an unsafe way.
Rhino.Geometry.MeshUnwrapMethod
Unwrapping method used
Rhino.Geometry.MeshUnwrapper
Unwraps meshes and stores the result in their texture coordinates
Rhino.Geometry.MorphControl
Represents a geometry that is able to control the morphing behavior of some other geometry.
Rhino.Geometry.NurbsCurve
Represents a Non Uniform Rational B-Splines (NURBS) curve.
Rhino.Geometry.NurbsCurve.NurbsCurveEndConditionType
What end conditions to set
Rhino.Geometry.NurbsCurveFitParameters
The NURBS curve fit tool creates a NURBS curve that approximates an existing curve. The NurbsCurveFitParameters class contains the paramters that determine NURBS curve properties (degree, point count, ...) and other fitting contstraints.
Rhino.Geometry.NurbsCurveFitParameters.Intensity
The Intensity enum is used to select a predefined or a custom value for the smoothing, uniformity, and curvature bias coefficients.
Rhino.Geometry.NurbsCurveFitParameters.KinkSplit
The KinkSplit enum is used to determine how target curve kinks (abrupt changes in target or curvature) are handled during rebuilding.
Rhino.Geometry.NurbsCurveFitParameters.TangentMatch
The TangentMatch enum is used to constrain the tangents of the rebuilt curve to match those of the target curve.
Rhino.Geometry.NurbsSurface
Represents a Non Uniform Rational B-Splines (NURBS) surface.
Rhino.Geometry.OrdinateDimension
Represents an ordinate dimension
Rhino.Geometry.OrdinateDimension.MeasuredDirection
Ordinate dimension measures x or y direction
Rhino.Geometry.Particle
Represents a simple particle.

This base class only defines position and display properties (size, color, bitmap id). You will most likely create a class that derives from this particle class to perform some sort of physical simulation (movement over time or frames).

Rhino.Geometry.ParticleSystem

PipeCapMode

Since v5.0
Rhino.Geometry.PipeCapMode
Styles used for creating Brep pipes.
Rhino.Geometry.Plane
Represents the value of a center point and two axes in a plane in three dimensions.

PlaneFitResult

Since v5.0
Rhino.Geometry.PlaneFitResult
Enumerates all possible outcomes of a Least-Squares plane fitting operation.
Rhino.Geometry.PlaneSurface
Represents a plane surface.
Rhino.Geometry.Point
Represents a geometric point.

This is fundamentally a class that derives from GeometryBase and contains a single Point3d location.

Rhino.Geometry.Point2d
Represents the two coordinates of a point in two-dimensional space, using double-precision floating point numbers.
Rhino.Geometry.Point2f
Represents the two coordinates of a point in two-dimensional space, using float-precision floating point numbers.
Rhino.Geometry.Point3d
Represents the three coordinates of a point in three-dimensional space, using double-precision floating point values.
Rhino.Geometry.Point3dGrid
Represents a rectangular grid of 3D points.
Rhino.Geometry.Point3f
Represents the three coordinates of a point in three-dimensional space, using float-precision floating point numbers.
Rhino.Geometry.Point4d
Represents the four coordinates of a point in four-dimensional space.

The W (fourth) dimension is often considered the weight of the point as seen in 3D space.

Rhino.Geometry.PointCloud
Represents a collection of coordinates with optional normal vectors and colors.
Rhino.Geometry.PointCloudItem
Represents a single item in a point cloud. A PointCloud item always has a location, but it has an optional normal vector and color.
Rhino.Geometry.PointCloudUnsafeLock
Permits access to the underlying PointCloud raw data structures in an unsafe way.
Rhino.Geometry.PointContainment
Defines enumerated values for closed curve/point spatial relationships.
Rhino.Geometry.PointFaceRelation
Enumerates the possible point/BrepFace spatial relationships.
Rhino.Geometry.PolyCurve
Represents a curve that is the result of joining several (possibly different) types of curves.
Rhino.Geometry.Polyline
Represents an ordered set of points connected by linear segments.

Polylines are closed if start and end points coincide.

Rhino.Geometry.PolylineCurve
Represents the geometry of a set of linked line segments.

This is fundamentally a class that derives from Curve and internally contains a Polyline.

PreserveEnd

Since v7.6
Rhino.Geometry.PreserveEnd
Preserves, or maintains, the shape of the opposite the one being edited.
Rhino.Geometry.PreserveIsoCurveMethod
The way the surface iso-lines align with the target
Rhino.Geometry.QuadRemeshParameters
Parameters for QuadRemesh method
Rhino.Geometry.QuadRemeshSymmetryAxis
Symmetrical meshing axis
Rhino.Geometry.Quaternion
Represents the four coefficient values in a quaternion.

The first value a is the real part, while the rest multiplies i, j and k, that are imaginary.

quaternion = a + bi + cj + dk

Rhino.Geometry.RadialDimension
Represents a dimension of a circular entity that can be measured with radius or diameter.

RailType

Since v6.0
Rhino.Geometry.RailType
Rail types used for creating filleted Brep edges
Rhino.Geometry.Ray3d
Represents an immutable ray in three dimensions, using position and direction.
Rhino.Geometry.RebuildCurveIntensity
RebuildCurveIntensity used used to specify rebuild smoothing and uniformity intensities.
Rhino.Geometry.RebuildCurveKinkSplitting
Rhino.Geometry.RebuildCurveOptions
Options used for curve rebuilding
Rhino.Geometry.RebuildCurveTangentMatching
RebuildCurveTangentMatch used used to specify tangent matching options.
Rhino.Geometry.Rectangle3d
Represents the values of a plane and two intervals that form an oriented rectangle in three dimensions.
Rhino.Geometry.ReduceMeshParameters
Parameters for Reduce method
Rhino.Geometry.RefitTrimKnotMode
The mode for adding kinots to the surface for fitting
Rhino.Geometry.RefitTrimSectionMode
The mode for dividing the surface into sections
Rhino.Geometry.RegionContainment
Defines enumerated values for closed curve/closed curve relationships.
Rhino.Geometry.RevSurface
Represents a surface of revolution.

Revolutions can be incomplete (they can form arcs).

Rhino.Geometry.RhinoVariationalDomain
The type of trimming domain
Rhino.Geometry.RibbonOffsetParameters
Advanced parameters for RibbonOffset Parameters mimic the RibbonOffset Command.
Rhino.Geometry.RibbonOffsetSurfaceMethod
Enum for RibbonOffset surface generation
Rhino.Geometry.RTree
Represents a spatial search structure based on implementations of the R-tree algorithm by Toni Gutman.
Rhino.Geometry.RTreeEventArgs
Represents event data that is passed when an item that meets certain criteria is found and the passed RTree event is raised.
Rhino.Geometry.ShrinkWrapParameters
Parameters for ShrinkWrap method
Rhino.Geometry.ShutLiningCurveInfo
Contains shutlining curve information. This is used in Mesh.WithShutLining(bool, double, IEnumerable<ShutLiningCurveInfo>).
Rhino.Geometry.Silhouette
Information about silhouette curves that are generated from geometry (surfaces, brep faces, meshes)

SilhouetteType

Since v6.0
Rhino.Geometry.SilhouetteType
Enumerates the different types of silhouettes and their origins.
Rhino.Geometry.SmoothingCoordinateSystem
The direction of the smoothing used by Curve, Surface, and Mesh Smooth.
Rhino.Geometry.SpaceMorph
Represents a spacial, Euclidean morph.
Rhino.Geometry.Sphere
Represents the plane and radius values of a sphere.
Rhino.Geometry.SquishDeformation
The types of deformation allowed in the squish process
Rhino.Geometry.Squisher
class used to wrap Squish functions
Rhino.Geometry.SquishFlatteningAlgorithm
Represents the type of flattening to use
Rhino.Geometry.SquishParameters
Parameters used by the 'Squish' command flattening algorithm
Rhino.Geometry.SubD
Subdivision surface
Rhino.Geometry.SubD.ExtraordinaryVertexCurvature
ON_SubD::ExtraordinaryVertexCurvature identifies what a curvature evaluation reports exactly on an extraordinary vertex. A SubD limit surface is C1 but generally not C2 at an extraordinary vertex. The mixed second partial does not exist there, so there is no second fundamental form and no curvature of the surface itself. Every other point of the surface, including the rest of an extraordinary vertex's corner quad, has a curvature and is unaffected by this setting.
Rhino.Geometry.SubD.NurbsSurfaceType
ON_SubD::NurbsSurfaceType specifies what type of NURBS surfaces are returned by ON_SubD.GetSurfaceNurbsFragments()
Rhino.Geometry.SubDAutomaticMeshToSubDContext
ON_SubD::AutomaticMeshToSubDContext identifies a context where meshes can automatically be converted to subds.
Rhino.Geometry.SubDChainType
SubD::ChainType specifies what edge and vertex tag tests are used when creating edge chains.
Rhino.Geometry.SubDComponent
A part of SubD geometry. Common base class for vertices, faces, and edges
Rhino.Geometry.SubDComponentLocation
The ON_SubDComponentLocation enum is used when an ON_SubD component is referenced and it is important to distinguish between the component's location in the SubD control net and its location in the SubD limit surface.
Rhino.Geometry.SubDComponentParameter
Identifies a point on the surface of a SubD.

SubDs have no global (u,v) parameterization. Instead a point on the surface is identified relative to a component of the SubD: a vertex, a point on an edge, or a point inside a face. A point inside a face is given by the index of the face corner it belongs to plus two parameters inside that corner, because a face with five or more sides has no single well behaved (u,v) domain.

Use SubD.ClosestPoint(Point3d, Point3d, SubDComponentParameter) to find a parameter and SubD.Evaluate(SubDComponentParameter, Point3d) and its overloads to evaluate one.

Rhino.Geometry.SubDCreationOptions
Options used for creating a SubD
Rhino.Geometry.SubDCreationOptions.ConcaveCornerOption
Defines how concave corners are treated.
Rhino.Geometry.SubDCreationOptions.ConvexCornerOption
Defines how convex corners are treated.
Rhino.Geometry.SubDCreationOptions.InteriorCreaseOption
Specifies the test used to determine when an interior mesh edge generates an interior SubD creased edge.
Rhino.Geometry.SubDCreationOptions.TextureCoordinateOption
Specifies how texture coordinate information is transferred from the mesh to the SubD.
Rhino.Geometry.SubDDisplayParameters
A collection of parameters that are passed to functions that calculate a various representations of SubD objects.
Rhino.Geometry.SubDDisplayParameters.Density
Density enumeration
Rhino.Geometry.SubDEdge
Single edge of a SubD

SubDEdgeChain

Since v8.36
Rhino.Geometry.SubDEdgeChain
An ordered run of connected SubD edges.

Consecutive edges in a chain share a vertex, and each edge carries the direction it is traversed with, so the chain has a start and an end even when the individual edges do not agree on orientation. Chains are what commands like Bridge, Loft and edge sharpening operate on.

Rhino.Geometry.SubDEdgeSharpness
Sharpness values for the two ends of a SubD edge.

A sharp SubD edge is an edge where the limit surface makes a tighter "fillet radius" around the edge than a smooth edge would, while still staying smooth, unlike a crease edge. It is achieved by applying the crease edge subdivision rules for the number of subdivisions given by the sharpness value, and the smooth edge subdivision rules after that. Sharpness can differ at the two ends of an edge.

Rhino.Geometry.SubDEdgeTag
ON_SubDEdgeTag identifies the type of subdivision edge. Different tags use different subdivision algorithms to calculate the subdivision point.
Rhino.Geometry.SubDEdgeType
ON_SubDEdgeType describes a subdivision edge. ON_SubDEdgeType is typically used when generating text descriptions or filtering edges during selection processes. Do not confuse ON_SubDEdgeType and ON_SubDEdgeTag. The unique types are single bits and suitable for use in bitwise logic.
Rhino.Geometry.SubDEndCapStyle
ON_SubDEndCapStyle enumerates the type of end caps functions like ON_SubD::CreateCylinder will create. Use ON_SubDEndCapStyleFromUnsigned(integer value) to convert integer values to an ON_SubDEndCapStyle. Use ON_SubDEndCapStyleToString(end_cap_style) to convert ON_SubDEndCapStyle values to string descriptions.
Rhino.Geometry.SubDFace
Single face of a SubD
Rhino.Geometry.SubDFriendlyKnotType
ON_SubD::SubDFriendlyKnotType identifies the types of subd friendly NURBS knot vectors. SubD friendly NURBS curves and surfacaes are always cubic and nonrational. Any time there is a multiple knot, the 2nd derivative is zero at the corresponding parameter. SubD friendly NURBS curves are either periodic or have zero 2nd derivative at the ends.
Rhino.Geometry.SubDFromSurfaceMethods
ON_SubDFromSurfaceParameters::Method are ways to create a SubD from a surface.
Rhino.Geometry.SubDHashType
ON_SubDHashType used used to specify what type of SubD information is hashed (topology or geometry).
Rhino.Geometry.SubDPatchStyle
SubD::PatchStyle identifies the style of patch used to fill holes.
Rhino.Geometry.SubDSurfaceInterpolator
Interpolate some or all of the vertices limit surface positions in a SubD to specified locations. NB: It is recommended not to use these methods to interpolate more than 1000 vertices. SubD.SetVertexSurfacePoint(uint, Point3d) SubD.InterpolateSurfacePoints(Point3d[]) SubD.InterpolateSurfacePoints(uint[], Point3d[]) SubDVertex.SurfacePoint()
Rhino.Geometry.SubDSurfaceInterpolator.MaximumCounts
Stores maximum count values for the solver to work in reasonable time.
Rhino.Geometry.SubDTextureCoordinateType
ON_SubDTextureCoordinateType identifies the way ON_SubDMeshFragment texture coordinates are set from an ON_SubDFace.
Rhino.Geometry.SubDToBrepOptions
Options used for converting a SubD to a Brep
Rhino.Geometry.SubDToBrepOptions.ExtraordinaryVertexProcessOption
ON_SubDToBrepParameters::Vertex identifies the options for post processing extraorindary vertices.
Rhino.Geometry.SubDVertex
Single vertex of a SubD
Rhino.Geometry.SubDVertexFacetType
Summarizes the number of edges in faces in the whole object.
Rhino.Geometry.SubDVertexTag
ON_SubDVertexTag identifies the type of subdivision vertex. Different tags use different subdivision algorithms to determine where the subdivision point and limit point are located. There are topological constraints that restrict which tags can be assigned.
Rhino.Geometry.SumSurface
Represents a sum surface, or an extrusion of a curve along a curved path.
Rhino.Geometry.Surface
Represents a base class that is common to most RhinoCommon surface types.

A surface represents an entity that can be all visited by providing two independent parameters, usually called (u, v), or sometimes (s, t).

Rhino.Geometry.SurfaceCurvature
Maintains computed information for principal surface curvature evaluation.
Rhino.Geometry.SurfaceDirectionIndicators
Surface direction indicators can be drawn by a display pipeline.
Rhino.Geometry.SurfaceFilletBase
New interactive FilletSrf
Rhino.Geometry.SurfaceProxy
Provides a base class to brep faces and other surface proxies.

SweepBlend

Since v7.0
Rhino.Geometry.SweepBlend
Blend types for creating swept surfaces

SweepFrame

Since v7.0
Rhino.Geometry.SweepFrame
Frame types for creating swept surfaces

SweepMiter

Since v7.0
Rhino.Geometry.SweepMiter
Miter types for creating swept surfaces
Rhino.Geometry.SweepOneRail
Utility class for generating Breps by sweeping cross section curves over a single rail curve. Note, this class has been superseded by the Rhino.Geometry.Brep.CreateFromSweep static functions.

SweepRebuild

Since v6.16
Rhino.Geometry.SweepRebuild
Rebuild types for creating swept surfaces
Rhino.Geometry.SweepTwoRail
Utility class for generating Breps by sweeping cross section curves over two rail curves. Note, this class has been superseded by the Rhino.Geometry.Brep.CreateFromSweep static functions.
Rhino.Geometry.TextDot
Represents a text dot, or an annotation entity with text that always faces the camera and always has the same size.

This class refers to the geometric element that is independent from the document.

Rhino.Geometry.TextEntity
Rhino.Geometry.TextJustification
Specifies enumerated constants used to indicate the internal alignment and justification of text.

TextRunType

Since v6.0
Rhino.Geometry.TextRunType
Rhino.Geometry.Torus
Represents the value of a plane and two radii in a torus that is oriented in three-dimensional space.
Rhino.Geometry.Transform
Represents the values in a 4x4 transform matrix.

This is parallel to C++ ON_Xform.

Rhino.Geometry.Transform2d
Represents the values in a 2d affine transformation.

This is parallel to C++ ON_Xform2d.

Rhino.Geometry.TransformRigidType
Lists all possible outcomes for rigid transformation.
Rhino.Geometry.TransformSimilarityType
Lists all possible outcomes for transform similarity.
Rhino.Geometry.Triangle3d
Represents a triangle, modeled using double three points that use double-precision floating point numbers.
Rhino.Geometry.Unroller
Represents the operation of unrolling a single surface.
Rhino.Geometry.Vector2d
Represents the two components of a vector in two-dimensional space, using double-precision floating point numbers.
Rhino.Geometry.Vector2f
Represents the two components of a vector in two-dimensional space, using float-precision floating point numbers.
Rhino.Geometry.Vector3d
Represents the three components of a vector in three-dimensional space, using double-precision floating point numbers.
Rhino.Geometry.Vector3f
Represents the three components of a vector in three-dimensional space, using float-precision floating point numbers.

VertexAligner

Since v9.0
Rhino.Geometry.VertexAligner
Moves vertices of different kinds of geometry onto one another, within a distance.

See the

_AlignVertices
Rhino command for more information.

Rhino.Geometry.VolumeMassProperties
Contains static initialization methods and allows access to the computed metrics of volume, volume centroid and volume moments in in solid meshes, in solid surfaces and in solid (closed) boundary representations.