Class TCubeNode_1

Unit

Declaration

type TCubeNode_1 = class(TAbstractGeometryNode_1)

Description

This item has no description. Showing description inherited from TAbstractGeometryNode_1.

Geometry node allowed only in VRML <= 1.0.

In VRML 1.0 shape nodes are allowed pretty everywhere, while VRML 2.0 has different idea of how shapes are handled (they must be inside Shape node), so no shape node is suitable at the same time for VRML 1.0 and VRML 2.0.

Hierarchy

Overview

Methods

Public function Proxy(var State: TX3DGraphTraverseState): TAbstractGeometryNode; override;
Public function BoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;
Public function LocalBoundingBox(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): TBox3D; override;
Public function TrianglesCount(State: TX3DGraphTraverseState; ProxyGeometry: TAbstractGeometryNode; ProxyState: TX3DGraphTraverseState): Cardinal; override;
Public function AutoGenerate3DTexCoords: boolean; override;
Public procedure CreateNode; override;
Public class function ClassX3DType: string; override;
Public class function ForVRMLVersion(const Version: TX3DVersion): Boolean; override;

Properties

Public property FdWidth: TSFFloat read FFdWidth;
Public property Width: Single read GetWidth write SetWidth;
Public property FdHeight: TSFFloat read FFdHeight;
Public property Height: Single read GetHeight write SetHeight;
Public property FdDepth: TSFFloat read FFdDepth;
Public property Depth: Single read GetDepth write SetDepth;

Description

Methods

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

This item has no description.

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

This item has no description.

Public function AutoGenerate3DTexCoords: boolean; override;

This item has no description. Showing description inherited from TAbstractGeometryNode.AutoGenerate3DTexCoords.

Should renderer automatically generate 3D texture coordinates, in case we will apply 3D texture on this geometry.

The generated coordinates will follow the X3D specification at "Texturing3D" component: "Texture coordinate generation for primitive objects". The 3D texture space will be mapped nicely to the shape bounding box.

Implementation in this class (TAbstractGeometryNode) returns always False. Override it for primitives that have no texture coordinates to return True.

Public procedure CreateNode; override;

This item has no description. Showing description inherited from TAbstractGeometryNode_1.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 class function ForVRMLVersion(const Version: TX3DVersion): Boolean; override;

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

Some nodes are present only in specific VRML/X3D version. This functions decides it.

For example some nodes can only work in VRML < 2.0, some others only in VRML >= 2.0. There are even some pairs of nodes: for example TConeNode_1 works with VRML < 2.0, TConeNode works with VRML >= 2.0.

NodesManager will use this.

Default implementation of this function returns always True. Generally, I don't try to set this too aggresively — in other words, for all cases when it's sensible, I allow nodes to be used in every VRML/X3D version, even when official specification doesn't. This means that when reading VRML 1.0 files actually a large part of VRML 2.0 is allowed too, and also while reading VRML 2.0 many constructs from VRML 1.0 (officially no longer present in VRML 2.0) are allowed too. I'm trying to support what I call a "sum of VRML 1.0 and 2.0".

In practice I only use this function when various VRML/X3D versions specify the same node name but

  • With different fields.

    For example Cone and Cylinder have slightly different fields, due to the fact that VRML 2.0 resigned from using TSFBitMask fields.

  • With different behavior.

    For example definitions of Sphere for VRML 1.0 and 2.0 are practically equal. However, the behavior from where to take texture and material info is different — in VRML 1.0 we take last Texture2, Material etc. nodes, while in VRML 2.0 we look in parent Shape's "appearance" field. So once again two different Sphere classes are needed.

Properties

Public property FdWidth: TSFFloat read FFdWidth;

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

Public property Width: Single read GetWidth write SetWidth;

This item has no description.

Public property FdHeight: TSFFloat read FFdHeight;

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

Public property Height: Single read GetHeight write SetHeight;

This item has no description.

Public property FdDepth: TSFFloat read FFdDepth;

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

Public property Depth: Single read GetDepth write SetDepth;

This item has no description.


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