Class TAbstractNurbsSurfaceGeometryNode

Unit

Declaration

type TAbstractNurbsSurfaceGeometryNode = class(TAbstractParametricGeometryNode)

Description

Abstract geometry type for all types of NURBS surfaces.

Hierarchy

Overview

Methods

Protected function DirectEnumerateActive(Func: TEnumerateChildrenFunction): Pointer; override;
Public function Proxy(var State: TX3DGraphTraverseState): TAbstractGeometryNode; override;
Public function LocalBoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;
Public function BoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;
Public function TrianglesCount(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): Cardinal; override;
Public function InternalCoord(State: TX3DGraphTraverseState; out ACoord: TMFVec3f): boolean; override;
Public function CoordField: TSFNode; override;
Public function SolidField: TSFBool; override;
Public function Point(const U, V: Single; const OutputNormal: PVector3 = nil): TVector3;
Public procedure CreateNode; override;
Public class function ClassX3DType: string; override;
Public procedure SetWeight(const Value: array of Double); overload;
Public procedure SetWeight(const Value: TDoubleList); overload;
Public procedure SetUKnot(const Value: array of Double); overload;
Public procedure SetUKnot(const Value: TDoubleList); overload;
Public procedure SetVKnot(const Value: array of Double); overload;
Public procedure SetVKnot(const Value: TDoubleList); overload;

Properties

Public property FdControlPoint: TSFNode read FFdControlPoint;
Public property ControlPoint: TAbstractCoordinateNode read GetControlPoint write SetControlPoint;
Public property FdTexCoord: TSFNode read FFdTexCoord;
Public property FdUTessellation: TSFInt32 read FFdUTessellation;
Public property UTessellation: Integer read GetUTessellation write SetUTessellation;
Public property FdVTessellation: TSFInt32 read FFdVTessellation;
Public property VTessellation: Integer read GetVTessellation write SetVTessellation;
Public property FdWeight: TMFDouble read FFdWeight;
Public property FdSolid: TSFBool read FFdSolid;
Public property FdUClosed: TSFBool read FFdUClosed;
Public property UClosed: Boolean read GetUClosed write SetUClosed;
Public property FdUDimension: TSFInt32 read FFdUDimension;
Public property UDimension: Integer read GetUDimension write SetUDimension;
Public property FdUKnot: TMFDouble read FFdUKnot;
Public property FdUOrder: TSFInt32 read FFdUOrder;
Public property UOrder: Integer read GetUOrder write SetUOrder;
Public property FdVClosed: TSFBool read FFdVClosed;
Public property VClosed: Boolean read GetVClosed write SetVClosed;
Public property FdVDimension: TSFInt32 read FFdVDimension;
Public property VDimension: Integer read GetVDimension write SetVDimension;
Public property FdVKnot: TMFDouble read FFdVKnot;
Public property FdVOrder: TSFInt32 read FFdVOrder;
Public property VOrder: Integer read GetVOrder write SetVOrder;

Description

Methods

Protected function DirectEnumerateActive(Func: TEnumerateChildrenFunction): Pointer; override;

This item has no description. Showing description inherited from TX3DNode.DirectEnumerateActive.

Enumerate all active child nodes of given node.

"Active nodes" are the ones affecting current look or collisions, e.g. from Switch node only one child will be enumerated. See Traverse for more precise definition.

"Direct" means that this enumerates only direct descendants, i.e. this is not recursive. See methods like Traverse or EnumerateNodes if you want recursive behavior.

This can enumerate both VRML1Children nodes and nodes within TSFNode and TMFNode fields.

Default implementation in this class enumerates all Children nodes of VRML 1.0. If you need to remove some children for VRML 1.0 (e.g. for Switch or LOD nodes) or add some children for VRML 2.0 you have to override this. You do not need to call inherited when overriding this — in fact, you should not, if you want to omit some nodes.

Stops and returns immediately if Func returns non-nil for some child.

Public function Proxy(var State: TX3DGraphTraverseState): TAbstractGeometryNode; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.Proxy.

Converts this node to another node class that may be better supported.

Typically, converts some complex geometry node (like Extrusion or Teapot) into more common node like IndexedFaceSet or IndexedTriangleSet. TShape class wraps this method into a more comfortable interface, that is TShape methods simply automatically convert geometry nodes to their proxy versions if needed.

In the base TAbstractGeometryNode class, returns Nil indicating that no conversion is known.

The resulting node's Name (if the result is not Nil) must be equal to our Name.

Some Proxy implementations (especially for VRML 1.0) will have to create new State (TX3DGraphTraverseState) instance along with a new geometry node. You should do this by copying the State into a new TX3DGraphTraverseState instance, and modyfying the State reference. Simply speaking, do

#
        State := TX3DGraphTraverseState.CreateCopy(State);

#)

You should not just modify the fields of the provided State instance. (Reasoning: some proxy methods rely on getting the original State, e.g. with original MaterialBinding, not the transformed state, to work correctly.)

You can modify State variable only when returning non-nil geometry.

Public function LocalBoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;

This item has no description.

Public function BoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.BoundingBox.

Calculate bounding box of this geometry node. They require State of this node during VRML traverse state — this is mainly for VRML 1.0 nodes, that depend on such state.

LocalBoundingBox gives a bounding box ignoring current transformation (or, equivalently, assuming like Transform = IdentityMatrix). Normal BoundingBox gives a bounding box taking current transformation into account.

Notes for descendants implementors:

The default implementations of these methods in TAbstractGeometryNode try to be smart and cover all common bases, so that you have to do as little work as possible to implement working descendant.

  1. For nodes based on coordinates (when InternalCoord returns True), LocalBoundingBox and BoundingBox already have optimal and correct implementation in this class. Using Coord and CoordIndex, no other information is needed.

  2. For other nodes, we first check ProxyGeometry and ProxyState. If ProxyGeometry is non-nil, we assume these came from Proxy call and we will use them to calculate bounding boxes, local and not local.

    So for nodes with Proxy overridden, you don't have to implement bounding box calculation, instead a ProxyGeometry will be created and provided here by the caller. This will work Ok if Proxy node will have bounding box calculation implemented.

    You can always override these methods, if you don't want to use proxy (for example, maybe there exists much faster method to calculate bounding box, or maybe tighter bounding box may be calculated directly).

  3. For other nodes (not coordinate-based and without a proxy):

    The default implementation of LocalBoundingBox just calls BoundingBox with a specially modified State, such that Transform is identity.

    The default implementation of BoundingBox, in turn, just calls LocalBoundingBox and transforms this bounding box.

    So the default implementations call each other, and will loop infinitely... But if you override any one of them (local or not local), the other one will magically work.

    Note that the default implementation of LocalBoundingBox may be non-optimal as far as time is concerned, as we'll do useless multiplications by identity matrix. And the default implementation of BoundingBox may generate non-optimal bounding box, more direct approach (transforming each vertex) may give much tightier bounding box.

    So you only have to override one method — although if you want the best implementation, fastest and with the best tight bounding boxes, you may need to override both of them for some nodes.

Public function TrianglesCount(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): Cardinal; override;

This item has no description.

Public function InternalCoord(State: TX3DGraphTraverseState; out ACoord: TMFVec3f): boolean; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.InternalCoord.

Return node's list of coordinates. Returns False if node is not based on coordinates. Returns True and sets ACoord if the node is based on coordinates. Even when returns True, it can set ACoord = Nil, which means that node is based on coordinates but they are empty right now (so for example bounding box may be considered empty).

In base TAbstractGeometryNode class this always returns False.

Override this for descendants that have some kind of "coord" field, then this should return True and set ACoord to coord.point field, assuming that coord is set and specifies Coordinate node. Override this even if coordinates affect the look indirectly, e.g. NURBS "controlPoint" fields also should be returned here. Otherwise should return True and set ACoord = Nil.

For VRML 1.0, coord may be taken from State, that's why we have to pass current traverse state here.

Public function CoordField: TSFNode; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.CoordField.

Node's "coord" field where you can place TCoordinateNode, or Nil if not available.

This gives you more possibilities than the InternalCoord and InternalCoordinates methods (as you can assign texCoord using this). However, it doesn't work for old VRML 1.0 (since they have coordinate information, but no "coord" field).

Public function SolidField: TSFBool; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.SolidField.

Is backface culling used. Nil if given geometry node doesn't have a field to control it.

Public function Point(const U, V: Single; const OutputNormal: PVector3 = nil): TVector3;

Get the position of a point on the surface.

The returned position is in the local transformation space of this shape. This method is guaranteed to work the same, regardless if this node is part of any TX3DRootNode and TCastleSceneCore or not.

Parameters
U
First parameter of the parametric surface, in [0..1] range.
V
Second parameter of the parametric surface, in [0..1] range.
OutputNormal
Optional. If non-nil, will be set to the normal, that is, normalized direction in 3D that is orthogonal to the surface at this point.
Public procedure CreateNode; override;

This item has no description. Showing description inherited from TAbstractParametricGeometryNode.CreateNode.

Automatically generated node properties.

Do not edit this file manually! To add new properties: - add them to the text files in tools/internal/x3d-nodes-to-pascal/nodes-specification/ , - and regenerate include files by running x3d-nodes-to-pascal

Public class function ClassX3DType: string; override;

This item has no description. Showing description inherited from TX3DNode.ClassX3DType.

Node type name in VRML/X3D, for this class. Normal VRML/X3D node classes should override this to return something non-empty, and then X3DType automatically will return the same value.

Empty for classes that don't have a hardcoded VRML/X3D node name, like a special TX3DUnknownNode. Such special classes should override then X3DType to return actual non-empty name there.

You usually should call X3DType. The only use of this method is that it works on classes (it's "class function"), without needing at actual instance.

Public procedure SetWeight(const Value: array of Double); overload;

This item has no description.

Public procedure SetWeight(const Value: TDoubleList); overload;

This item has no description.

Public procedure SetUKnot(const Value: array of Double); overload;

This item has no description.

Public procedure SetUKnot(const Value: TDoubleList); overload;

This item has no description.

Public procedure SetVKnot(const Value: array of Double); overload;

This item has no description.

Public procedure SetVKnot(const Value: TDoubleList); overload;

This item has no description.

Properties

Public property FdControlPoint: TSFNode read FFdControlPoint;

Internal wrapper for property ControlPoint. This wrapper API may change, we advise to access simpler ControlPoint instead.

Public property ControlPoint: TAbstractCoordinateNode read GetControlPoint write SetControlPoint;

This item has no description.

Public property FdTexCoord: TSFNode read FFdTexCoord;

Internal wrapper for property TexCoord. This wrapper API may change, we advise to access simpler TexCoord instead.

Public property FdUTessellation: TSFInt32 read FFdUTessellation;

Internal wrapper for property UTessellation. This wrapper API may change, we advise to access simpler UTessellation instead.

Public property UTessellation: Integer read GetUTessellation write SetUTessellation;

This item has no description.

Public property FdVTessellation: TSFInt32 read FFdVTessellation;

Internal wrapper for property VTessellation. This wrapper API may change, we advise to access simpler VTessellation instead.

Public property VTessellation: Integer read GetVTessellation write SetVTessellation;

This item has no description.

Public property FdWeight: TMFDouble read FFdWeight;

Internal wrapper for property Weight. This wrapper API may change, we advise to access simpler Weight instead.

Public property FdSolid: TSFBool read FFdSolid;

Internal wrapper for property Solid. This wrapper API may change, we advise to access simpler Solid instead.

Public property FdUClosed: TSFBool read FFdUClosed;

Internal wrapper for property UClosed. This wrapper API may change, we advise to access simpler UClosed instead.

Public property UClosed: Boolean read GetUClosed write SetUClosed;

This item has no description.

Public property FdUDimension: TSFInt32 read FFdUDimension;

Internal wrapper for property UDimension. This wrapper API may change, we advise to access simpler UDimension instead.

Public property UDimension: Integer read GetUDimension write SetUDimension;

This item has no description.

Public property FdUKnot: TMFDouble read FFdUKnot;

Internal wrapper for property UKnot. This wrapper API may change, we advise to access simpler UKnot instead.

Public property FdUOrder: TSFInt32 read FFdUOrder;

Internal wrapper for property UOrder. This wrapper API may change, we advise to access simpler UOrder instead.

Public property UOrder: Integer read GetUOrder write SetUOrder;

This item has no description.

Public property FdVClosed: TSFBool read FFdVClosed;

Internal wrapper for property VClosed. This wrapper API may change, we advise to access simpler VClosed instead.

Public property VClosed: Boolean read GetVClosed write SetVClosed;

This item has no description.

Public property FdVDimension: TSFInt32 read FFdVDimension;

Internal wrapper for property VDimension. This wrapper API may change, we advise to access simpler VDimension instead.

Public property VDimension: Integer read GetVDimension write SetVDimension;

This item has no description.

Public property FdVKnot: TMFDouble read FFdVKnot;

Internal wrapper for property VKnot. This wrapper API may change, we advise to access simpler VKnot instead.

Public property FdVOrder: TSFInt32 read FFdVOrder;

Internal wrapper for property VOrder. This wrapper API may change, we advise to access simpler VOrder instead.

Public property VOrder: Integer read GetVOrder write SetVOrder;

This item has no description.


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