Class TShape

Unit

Declaration

type TShape = class(TShapeTree)

Description

Shape is a geometry node Geometry instance and it's State. For VRML >= 2.0, this usually corresponds to a single instance of actual VRML Shape node. It allows to perform many operations that need to know both geometry and it's current state (parent Shape node, current transformation and such).

This class caches results of methods LocalBoundingBox, BoundingBox, and most others (see TShapeValidities for hints). This means that things work fast, but this also means that you must manually call Changed when you changed some properties of Geometry or contents of State.

But note that you can't change Geometry or State to different objects — they are readonly properties.

Also note that if you're using TCastleSceneCore class then you don't have to worry about calling Changed of items in TCastleSceneCore.Shapes. All you have to do is to call appropriate Changed* methods of TCastleSceneCore.

Hierarchy

Overview

Nested Types

Published TNormalsCached = (...);

Methods

Public constructor Create(AParentScene: TObject; AOriginalGeometry: TAbstractGeometryNode; AOriginalState: TX3DGraphTraverseState; ParentInfo: PTraversingInfo);
Public destructor Destroy; override;
Public function Geometry(const OverTriangulate: boolean = true): TAbstractGeometryNode;
Public function State(const OverTriangulate: boolean = true): TX3DGraphTraverseState;
Public function LocalBoundingBox: TBox3D;
Public function BoundingBox: TBox3D;
Public function VerticesCount(OverTriangulate: boolean): Cardinal;
Public function TrianglesCount(OverTriangulate: boolean): Cardinal;
Public function GeometryArrays(OverTriangulate: boolean): TGeometryArrays;
Public function BoundingSphereCenter: TVector3;
Public function BoundingSphereRadiusSqr: Single;
Public function BoundingSphereRadius: Single;
Public function FrustumBoundingSphereCollisionPossible( const Frustum: TFrustum): TFrustumCollisionPossible;
Public function FrustumBoundingSphereCollisionPossibleSimple( const Frustum: TFrustum): boolean;
Public procedure Changed(const InactiveOnly: boolean; const Changes: TX3DChanges); virtual;
Public function InternalOctreeTriangles: TTriangleOctree;
Public function InternalTriangleOctreeLimits: POctreeLimits;
Public function Blending: boolean;
Public function Transparent: boolean; deprecated 'use Blending';
Public procedure Traverse(Func: TShapeTraverseFunc; const OnlyActive: boolean; const OnlyVisible: boolean = false; const OnlyCollidable: boolean = false); override;
Public function ShapesCount(const OnlyActive: boolean; const OnlyVisible: boolean = false; const OnlyCollidable: boolean = false): Cardinal; override;
Public function Visible: boolean;
Public function Collidable: boolean;
Public function RayCollision( const Tag: TMailboxTag; out Intersection: TVector3; out IntersectionDistance: Single; const RayOrigin, RayDirection: TVector3; const ReturnClosestIntersection: boolean; const TriangleToIgnore: PTriangle; const IgnoreMarginAtStart: boolean; const TrianglesToIgnoreFunc: TTriangleIgnoreFunc): PTriangle;
Public function SegmentCollision( const Tag: TMailboxTag; out Intersection: TVector3; out IntersectionDistance: Single; const Pos1, Pos2: TVector3; const ReturnClosestIntersection: boolean; const TriangleToIgnore: PTriangle; const IgnoreMarginAtStart: boolean; const TrianglesToIgnoreFunc: TTriangleIgnoreFunc): PTriangle;
Public function NormalsSmooth(const OverTriangulate, FromCcw: boolean): TVector3List;
Public function NormalsFlat(const OverTriangulate, FromCcw: boolean): TVector3List;
Public function NormalsCreaseAngle(const OverTriangulate, FromCcw: boolean; const CreaseAngle: Single): TVector3List;
Public function EnumerateTextures(Enumerate: TEnumerateShapeTexturesFunction): Pointer; override;
Public function UsesTexture(Node: TAbstractTextureNode): boolean;
Public function ShadowCaster: boolean;
Public procedure Triangulate(OverTriangulate: boolean; TriangleEvent: TTriangleEvent);
Public procedure LocalTriangulate(OverTriangulate: boolean; TriangleEvent: TTriangleEvent);
Public function DebugInfo(const Indent: string = ''): string; override;
Public function NiceName: string;
Public function Node: TAbstractShapeNode;
Public function InternalMaterialProperty: TMaterialProperty;
Public function MaterialProperty: TMaterialProperty; deprecated 'use InternalMaterialProperty, or (better) do not use it at all -- this is internal';

Properties

Public property OriginalGeometry: TAbstractGeometryNode read FOriginalGeometry;
Public property OriginalState: TX3DGraphTraverseState read FOriginalState;
Public property InternalSpatial: TShapeSpatialStructures read FSpatial write SetSpatial;
Public property InternalTriangleOctreeProgressTitle: string read FTriangleOctreeProgressTitle write FTriangleOctreeProgressTitle;
Public property DynamicGeometry: boolean read FDynamicGeometry write FDynamicGeometry;
Public property GeometryParentNodeName: string read FGeometryParentNodeName;
Public property GeometryGrandParentNodeName: string read FGeometryGrandParentNodeName;
Public property GeometryGrandGrandParentNodeName: string read FGeometryGrandGrandParentNodeName;

Description

Nested Types

Published TNormalsCached = (...);
 
Values
  • ncSmooth
  • ncFlat
  • ncCreaseAngle

Methods

Public constructor Create(AParentScene: TObject; AOriginalGeometry: TAbstractGeometryNode; AOriginalState: TX3DGraphTraverseState; ParentInfo: PTraversingInfo);

Constructor.

Parameters
ParentInfo
Resursive information about parents, for the geometry node of given shape. Note that for VRML 2.0/X3D, the immediate parent of geometry node is always TShapeNode.
Public destructor Destroy; override;
 
Public function Geometry(const OverTriangulate: boolean = true): TAbstractGeometryNode;

Geometry of this shape. This may come from initial VRML/X3D node graph (see OriginalGeometry), or it may be processed by TAbstractGeometryNode.Proxy for easier handling.

Public function State(const OverTriangulate: boolean = true): TX3DGraphTraverseState;

State of this shape. This may come from initial VRML/X3D node graph (see OriginalState), or it may be processed by TAbstractGeometryNode.Proxy for easier handling.

Owned by this TShape class.

Public function LocalBoundingBox: TBox3D;

Calculate bounding box and vertices/triangles count, see TAbstractGeometryNode methods.

Public function BoundingBox: TBox3D;
 
Public function VerticesCount(OverTriangulate: boolean): Cardinal;
 
Public function TrianglesCount(OverTriangulate: boolean): Cardinal;
 
Public function GeometryArrays(OverTriangulate: boolean): TGeometryArrays;

Decompose the geometry into primitives, with arrays of per-vertex data.

Public function BoundingSphereCenter: TVector3;

Calculates bounding sphere based on BoundingBox. In the future this may be changed to use BoundingSphere method of TAbstractGeometryNode, when I will implement it. For now, BoundingSphere is always worse approximation of bounding volume than BoundingBox (i.e. BoundingSphere is always larger) but it may be useful in some cases when detecting collision versus bounding sphere is much faster than detecting them versus bounding box.

BoundingSphereRadiusSqr = 0 and BoundingSphereCenter is undefined if Box is empty.

Public function BoundingSphereRadiusSqr: Single;
 
Public function BoundingSphereRadius: Single;
 
Public function FrustumBoundingSphereCollisionPossible( const Frustum: TFrustum): TFrustumCollisionPossible;

Exactly equivalent to getting BoundingSphereCenter and BoundingSphereRadiusSqr and then using TFrustum.SphereCollisionPossible.

But it may be a little faster since it avoids some small speed problems (like copying memory contents when you get values of BoundingSphereXxx properties and checking twice are BoundingSphereXxx calculated).

Public function FrustumBoundingSphereCollisionPossibleSimple( const Frustum: TFrustum): boolean;

Exactly equivalent to getting BoundingSphereCenter and BoundingSphereRadiusSqr and then using TFrustum.SphereCollisionPossibleSimple.

But it may be a little faster since it avoids some small speed problems.

Public procedure Changed(const InactiveOnly: boolean; const Changes: TX3DChanges); virtual;

Notify this shape that you changed a field inside one of it's nodes (automatically done by TCastleSceneCore). This should be called when fields within Shape.Geometry, Shape.State.Last*, Shape.State.ShapeNode or such change.

Pass InactiveOnly = True is you know that this shape is fully in inactive VRML graph part (inactive Switch, LOD etc. children).

Including chTransform in Changes means something more than general chTransform (which means that transformation of children changed, which implicates many things — not only shape changes). Here, chTransform in Changes means that only the transformation of TShape.State changed (so only on fields ignored by EqualsNoTransform).

Public function InternalOctreeTriangles: TTriangleOctree;

The dynamic octree containing all triangles. It contains only triangles within this shape.

There is no distinction here between collidable / visible (as for TCastleSceneCore octrees), since only the whole shape may be marked as visible and/or collidable, not particular triangles.

The triangles are specified in local coordinate system of this shape (that is, they are independent from transformation within State.Transform). This allows the tree to remain unmodified when transformation of this shape changes.

This is automatically managed (initialized, updated, and used) by parent TCastleSceneCore. You usually don't need to know about this octree from outside.

To initialize this, add ssTriangles to InternalSpatial property, otherwise it's Nil. Parent TCastleSceneCore will take care of this (when parent TCastleSceneCore.Spatial contains ssDynamicCollisions, then all shapes contain ssTriangles within their InternalSpatial).

Parent TCastleSceneCore will take care to keep this octree always updated.

Parent TCastleSceneCore will also take care of actually using this octree: TCastleSceneCore.OctreeCollisions methods actually use the octrees of specific shapes at the bottom.

Public function InternalTriangleOctreeLimits: POctreeLimits;

Properties of created triangle octrees. See TriangleOctree unit comments for description.

Default value comes from DefLocalTriangleOctreeLimits.

They are used only when the octree is created, so usually you want to set them right before changing InternalSpatial from [] to something else.

Public function Blending: boolean;

Decide should the shape use alpha blending (partial transparency), looking at material, color, texture nodes (including at texture images contents).

This may look at the data of the texture node, so it should be called before any calls to TCastleSceneCore.FreeResources. It checks AlphaChannel of textures, so assumes that given shape textures are already loaded.

Public function Transparent: boolean; deprecated 'use Blending';

Warning: this symbol is deprecated: use Blending

 
Public procedure Traverse(Func: TShapeTraverseFunc; const OnlyActive: boolean; const OnlyVisible: boolean = false; const OnlyCollidable: boolean = false); override;
 
Public function ShapesCount(const OnlyActive: boolean; const OnlyVisible: boolean = false; const OnlyCollidable: boolean = false): Cardinal; override;
 
Public function Visible: boolean;

Is shape visible, according to VRML Collision node rules. Ths is simply a shortcut (with more obvious name) for State.InsideInvisible = 0.

Public function Collidable: boolean;

Is shape collidable, according to VRML Collision node rules. Ths is simply a shortcut (with more obvious name) for State.InsideIgnoreCollision = 0.

Public function RayCollision( const Tag: TMailboxTag; out Intersection: TVector3; out IntersectionDistance: Single; const RayOrigin, RayDirection: TVector3; const ReturnClosestIntersection: boolean; const TriangleToIgnore: PTriangle; const IgnoreMarginAtStart: boolean; const TrianglesToIgnoreFunc: TTriangleIgnoreFunc): PTriangle;

Equivalent to using OctreeTriangles.RayCollision, except this wil use the mailbox.

Public function SegmentCollision( const Tag: TMailboxTag; out Intersection: TVector3; out IntersectionDistance: Single; const Pos1, Pos2: TVector3; const ReturnClosestIntersection: boolean; const TriangleToIgnore: PTriangle; const IgnoreMarginAtStart: boolean; const TrianglesToIgnoreFunc: TTriangleIgnoreFunc): PTriangle;

Equivalent to using OctreeTriangles.SegmentCollision, except this wil use the mailbox.

Public function NormalsSmooth(const OverTriangulate, FromCcw: boolean): TVector3List;

Create normals suitable for this shape.

You can call this only when Geometry is coordinate-based X3D geometry, implementing Coord and having non-empty coordinates (that is, Geometry.Coord returns True and sets ACoord <> Nil), and having Geometry.CoordIndex <> Nil.

For NormalsSmooth, also Geometry.CoordIndex = Nil is allowed, but make sure that Geometry.InternalCoordPolygons is available. See CreateSmoothNormalsCoordinateNode.

  • Smooth normals are perfectly smooth, per-vertex.

    As an exception, you can call this even when coords are currently empty (Geometry.Coord returns True but ACoord is Nil), then result is also Nil.

  • Flat normals are per-face. Calculated by CreateFlatNormals.

  • Finally NormalsCreaseAngle creates separate normal per index (auto-smoothing by CreaseAngle).

The normals here are cached. So using these methods makes condiderable speedup if the shape will not change (Changed method) and will need normals many times (e.g. will be rendered many times).

Public function NormalsFlat(const OverTriangulate, FromCcw: boolean): TVector3List;
 
Public function NormalsCreaseAngle(const OverTriangulate, FromCcw: boolean; const CreaseAngle: Single): TVector3List;
 
Public function EnumerateTextures(Enumerate: TEnumerateShapeTexturesFunction): Pointer; override;
 
Public function UsesTexture(Node: TAbstractTextureNode): boolean;

Is the texture node Node possibly used by this shape. This is equivalent to checking does EnumerateShapeTextures return this shape.

Public function ShadowCaster: boolean;

Check is shape a shadow caster. Looks at Shape's Appearance.shadowCaster field (see https://castle-engine.io/x3d_extensions.php#section_ext_shadow_caster).

Public procedure Triangulate(OverTriangulate: boolean; TriangleEvent: TTriangleEvent);

Triangulate shape. Calls TriangleEvent callback for each triangle. LocalTriangulate returns coordinates in local shape transformation (that is, not transformed by State.Transform yet).

OverTriangulate determines if we should make more triangles for Gouraud shading. For example, it makes Cones and Cylinders divided into additional stacks.

Public procedure LocalTriangulate(OverTriangulate: boolean; TriangleEvent: TTriangleEvent);
 
Public function DebugInfo(const Indent: string = ''): string; override;
 
Public function NiceName: string;
 
Public function Node: TAbstractShapeNode;

Shape node in VRML/X3D graph. This is always present for VRML >= 2 (including X3D). For VRML 1.0 and Inventor this is Nil.

Public function InternalMaterialProperty: TMaterialProperty;

Material property associated with this shape's material/texture.

Public function MaterialProperty: TMaterialProperty; deprecated 'use InternalMaterialProperty, or (better) do not use it at all -- this is internal';

Warning: this symbol is deprecated: use InternalMaterialProperty, or (better) do not use it at all -- this is internal

 

Properties

Public property OriginalGeometry: TAbstractGeometryNode read FOriginalGeometry;

Original geometry node, that you get from a VRML/X3D graph.

Public property OriginalState: TX3DGraphTraverseState read FOriginalState;

Original state, that you get from a VRML/X3D graph.

Public property InternalSpatial: TShapeSpatialStructures read FSpatial write SetSpatial;

Which spatial structrues (octrees, for now) should be created and managed. This works analogous to TCastleSceneCore.Spatial, but this manages octrees within this TShape.

Parent TCastleSceneCore will take care to keep this value updated, you should only set TCastleSceneCore.Spatial from the outside.

Public property InternalTriangleOctreeProgressTitle: string read FTriangleOctreeProgressTitle write FTriangleOctreeProgressTitle;

If TriangleOctreeProgressTitle <> '', it will be shown during octree creation (through TProgress.Title). Will be shown only if progress is not active already (so we avoid starting "progress bar within progress bar").

Public property DynamicGeometry: boolean read FDynamicGeometry write FDynamicGeometry;

Local geometry is treated as dynamic (changes very often, like every frame). This is automatically detected and set to True, although you can also explicitly set this if you want.

Dynamic geometry has worse collision detection (using a crude approximation) and falls back to rendering method better for dynamic geometry (for example, marking VBO data as dynamic for OpenGL rendering).

Public property GeometryParentNodeName: string read FGeometryParentNodeName;

Node names of parents of the geometry node. Note that for X3D/VRML 2.0, GeometryParentNodeName is the same as Node.NodeName, because the parent of geometry node is always a TShapeNode.

Public property GeometryGrandParentNodeName: string read FGeometryGrandParentNodeName;
 
Public property GeometryGrandGrandParentNodeName: string read FGeometryGrandGrandParentNodeName;
 

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