HdInstancedBySchema Class Reference

A schema marking a prim as instanced by another prim. More...

#include <instancedBySchema.h>

Inheritance diagram for HdInstancedBySchema:

Classes
class	Builder
	Utility class for setting sparse sets of child data source fields to be filled as arguments into BuildRetained. More...

Public Member Functions
Member accessor
HD_API HdPathArrayDataSourceHandle	GetPaths () const
HD_API HdPathArrayDataSourceHandle	GetPrototypeRoots () const
Public Member Functions inherited from HdSchema
	HdSchema (HdContainerDataSourceHandle container)
HD_API HdContainerDataSourceHandle	GetContainer () const
	Returns the container data source that this schema is interpreting.
HD_API bool	IsDefined () const
	operator bool () const
	Returns true if this schema is applied on top of a non-null container.

Static Public Member Functions
Schema location
static HD_API const TfToken &	GetSchemaToken ()
	Returns a token where the container representing this schema is found in a container by default.
static HD_API const HdDataSourceLocator &	GetDefaultLocator ()
	Returns an HdDataSourceLocator (relative to the prim-level data source) where the container representing this schema is found by default.
Data source locators for members
The following methods return an HdDataSourceLocator (relative to the prim-level data source) where the data source for a member can be found. This is often useful for checking intersection against the HdDataSourceLocatorSet sent with HdDataSourceObserver::PrimsDirtied.
static HD_API const HdDataSourceLocator &	GetPathsLocator ()
	Prim-level relative data source locator to locate paths.
Schema construction
static HD_API HdContainerDataSourceHandle	BuildRetained (const HdPathArrayDataSourceHandle &paths, const HdPathArrayDataSourceHandle &prototypeRoots)

Schema retrieval
	HdInstancedBySchema (HdContainerDataSourceHandle container)
static HD_API HdInstancedBySchema	GetFromParent (const HdContainerDataSourceHandle &fromParentContainer)
	Retrieves a container data source with the schema's default name token "instancedBy" from the parent container and constructs a HdInstancedBySchema instance.

Additional Inherited Members
Public Types inherited from HdSchema
using	UnderlyingDataSource = HdContainerDataSource
Protected Member Functions inherited from HdSchema
template<typename T >
T::Handle	_GetTypedDataSource (TfToken name) const
	Returns a datasource of the requested type for the given name: schema implementations can use this to ask for child containers, sampled values, vectors, etc.
Protected Attributes inherited from HdSchema
HdContainerDataSourceHandle	_container

Detailed Description

A schema marking a prim as instanced by another prim.

Many renderers need to know not what prototypes an instancer has, but rather what instancers a prototype has; this is encoded in "instancedBy". A prim is "instancedBy" /Instancer if /Instancer has a prototype path that's a parent of the prim. A complicating exception is if /A instances /A/B, which instances /A/B/C, we don't consider /A to be instancing /A/B/C directly; this is to support nested explicit instancing of things like leaves/trees/forests.

This value is computed based on the instancer topology of instancer prims in the scene.

Note: if multiple instancers reference a prototype, it's possible for instancedBy to contain multiple entries. Some renderers may be able to read this directly, but some may need to duplicate prims with an op so that each prim has a single instancer, depending on how the renderer exposes instancing.

Definition at line 67 of file instancedBySchema.h.

Constructor & Destructor Documentation

HdInstancedBySchema()

HdInstancedBySchema ( HdContainerDataSourceHandle  container )

inline

Definition at line 73 of file instancedBySchema.h.

Member Function Documentation

BuildRetained()

static HD_API HdContainerDataSourceHandle BuildRetained ( const HdPathArrayDataSourceHandle &  paths, const HdPathArrayDataSourceHandle &  prototypeRoots  )

static

Deprecated:

Use Builder instead.

Builds a container data source which includes the provided child data sources. Parameters with nullptr values are excluded. This is a low-level interface. For cases in which it's desired to define the container with a sparse set of child fields, the Builder class is often more convenient and readable.

GetDefaultLocator()

static HD_API const HdDataSourceLocator & GetDefaultLocator ( )

static

Returns an HdDataSourceLocator (relative to the prim-level data source) where the container representing this schema is found by default.

GetFromParent()

static HD_API HdInstancedBySchema GetFromParent ( const HdContainerDataSourceHandle &  fromParentContainer )

static

Retrieves a container data source with the schema's default name token "instancedBy" from the parent container and constructs a HdInstancedBySchema instance.

Because the requested container data source may not exist, the result should be checked with IsDefined() or a bool comparison before use.

GetPathsLocator()

static HD_API const HdDataSourceLocator & GetPathsLocator ( )

static

Prim-level relative data source locator to locate paths.

GetSchemaToken()

static HD_API const TfToken & GetSchemaToken ( )

static

Returns a token where the container representing this schema is found in a container by default.

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The documentation for this class was generated from the following file:

• pxr/imaging/hd/instancedBySchema.h