HdStInstancer Class Reference

#include <instancer.h>

Inheritance diagram for HdStInstancer:

Public Member Functions
HDST_API	HdStInstancer (HdSceneDelegate *delegate, SdfPath const &id)
	Constructor. More...
HDST_API void	Sync (HdSceneDelegate *sceneDelegate, HdRenderParam *renderParam, HdDirtyBits *dirtyBits) override
HdBufferArrayRangeSharedPtr	GetInstancePrimvarRange () const
HDST_API VtIntArray	GetInstanceIndices (SdfPath const &prototypeId)
Public Member Functions inherited from HdInstancer
HD_API	HdInstancer (HdSceneDelegate *delegate, SdfPath const &id)
	Constructor. More...
virtual HD_API	~HdInstancer ()
SdfPath const &	GetId () const
	Returns the identifier. More...
SdfPath const &	GetParentId () const
	Returns the parent instancer identifier. More...
HdSceneDelegate *	GetDelegate () const
virtual HD_API void	Finalize (HdRenderParam *renderParam)
virtual HD_API HdDirtyBits	GetInitialDirtyBitsMask () const

Protected Member Functions
HDST_API void	_GetInstanceIndices (SdfPath const &prototypeId, std::vector< VtIntArray > *instanceIndicesArray)
HDST_API void	_SyncPrimvars (HdSceneDelegate *sceneDelegate, HdDirtyBits *dirtyBits)
Protected Member Functions inherited from HdInstancer
HD_API void	_UpdateInstancer (HdSceneDelegate *delegate, HdDirtyBits *dirtyBits)

Additional Inherited Members
Static Public Member Functions inherited from HdInstancer
static HD_API int	GetInstancerNumLevels (HdRenderIndex &index, HdRprim const &rprim)
static HD_API TfTokenVector const &	GetBuiltinPrimvarNames ()
static HD_API void	_SyncInstancerAndParents (HdRenderIndex &renderIndex, SdfPath const &instancerId)

Detailed Description

HdSt implements instancing by drawing each proto multiple times with a single draw call. Application of instance primvars (like transforms) is done in shaders. Instance transforms in particular are computed in ApplyInstanceTransform in instancing.glslfx.

If this instancer is nested, instance indices will be computed recursively by ascending the hierarchy. HdStInstancer computes a flattened index structure for each prototype by taking the cartesian product of the instance indices at each level.

For example:

• InstancerA draws instances [ProtoX, InstancerB, ProtoX, InstancerB]
• InstancerB draws instances [ProtoY, ProtoZ, ProtoY] The flattened index for Proto Y is: [0, 0, 1]; [1, 0, 3]; [2, 2, 1]; [3, 2, 3]; where the first tuple element is the position in the flattened index; the second tuple element is the position in Instancer B; and the last tuple element is the position in Instancer A.

The flattened index gives the number of times the proto is drawn, and the index tuple can be passed to the shader so that each instance can look up its instance primvars in the bound primvar arrays.

Definition at line 68 of file instancer.h.

Constructor & Destructor Documentation

HDST_API HdStInstancer::HdStInstancer	(	HdSceneDelegate *	delegate,
		SdfPath const &	id
	)

Constructor.

Member Function Documentation

HDST_API void HdStInstancer::_GetInstanceIndices ( SdfPath const &  prototypeId, std::vector< VtIntArray > *  instanceIndicesArray  )

protected

HDST_API void HdStInstancer::_SyncPrimvars ( HdSceneDelegate *  sceneDelegate, HdDirtyBits *  dirtyBits  )

protected

HDST_API VtIntArray HdStInstancer::GetInstanceIndices

(

SdfPath const &

prototypeId

)

Populates the instance index indirection buffer for prototypeId and returns a flat array of instance index tuples.

HdBufferArrayRangeSharedPtr HdStInstancer::GetInstancePrimvarRange ( ) const

inline

Definition at line 82 of file instancer.h.

HDST_API void HdStInstancer::Sync ( HdSceneDelegate *  sceneDelegate, HdRenderParam *  renderParam, HdDirtyBits *  dirtyBits  )

overridevirtual

Reimplemented from HdInstancer.

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

• pxr/imaging/hdSt/instancer.h