VTK
Classes | Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
vtkOpenGLInstanceCulling Class Reference

Frustum culling and LOD management. More...

#include <vtkOpenGLInstanceCulling.h>

Inheritance diagram for vtkOpenGLInstanceCulling:
[legend]
Collaboration diagram for vtkOpenGLInstanceCulling:
[legend]

Classes

struct  InstanceLOD
 

Public Types

typedef vtkObject Superclass
 

Public Member Functions

virtual vtkTypeBool IsA (const char *type)
 Return 1 if this class is the same type of (or a subclass of) the named class. More...
 
vtkOpenGLInstanceCullingNewInstance () const
 
void InitLOD (vtkPolyData *pd)
 Initialize LOD with a polydata. More...
 
void AddLOD (float distance, float targetReduction)
 Add a level of detail. More...
 
void BuildCullingShaders (vtkOpenGLShaderCache *cache, vtkIdType numInstances, bool withNormals)
 Build culling shader program (if not created yet) and binds it. More...
 
vtkOpenGLHelperGetHelper ()
 Get helper structure. More...
 
InstanceLODGetLOD (vtkIdType index)
 Get LOD structure. More...
 
vtkIdType GetNumberOfLOD ()
 Get number of LOD currently declared. More...
 
vtkOpenGLBufferObjectGetLODBuffer (vtkIdType index)
 Get the transform feedback buffer generated by the culling program. More...
 
void RunCullingShaders (vtkIdType numInstances, vtkOpenGLBufferObject *matrixBuffer, vtkOpenGLBufferObject *colorBuffer, vtkOpenGLBufferObject *normalBuffer)
 Run the culling program and generate LOD buffers. More...
 
virtual void SetColorLOD (bool)
 Overload color with unique color per LOD. More...
 
virtual bool GetColorLOD ()
 
- Public Member Functions inherited from vtkObject
 vtkBaseTypeMacro (vtkObject, vtkObjectBase)
 
virtual void DebugOn ()
 Turn debugging output on. More...
 
virtual void DebugOff ()
 Turn debugging output off. More...
 
bool GetDebug ()
 Get the value of the debug flag. More...
 
void SetDebug (bool debugFlag)
 Set the value of the debug flag. More...
 
virtual void Modified ()
 Update the modification time for this object. More...
 
virtual vtkMTimeType GetMTime ()
 Return this object's modified time. More...
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
unsigned long AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
unsigned long AddObserver (const char *event, vtkCommand *, float priority=0.0f)
 
vtkCommandGetCommand (unsigned long tag)
 
void RemoveObserver (vtkCommand *)
 
void RemoveObservers (unsigned long event, vtkCommand *)
 
void RemoveObservers (const char *event, vtkCommand *)
 
vtkTypeBool HasObserver (unsigned long event, vtkCommand *)
 
vtkTypeBool HasObserver (const char *event, vtkCommand *)
 
void RemoveObserver (unsigned long tag)
 
void RemoveObservers (unsigned long event)
 
void RemoveObservers (const char *event)
 
void RemoveAllObservers ()
 
vtkTypeBool HasObserver (unsigned long event)
 
vtkTypeBool HasObserver (const char *event)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
 Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, bool(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 Allow user to set the AbortFlagOn() with the return value of the callback method. More...
 
int InvokeEvent (unsigned long event, void *callData)
 This method invokes an event and return whether the event was aborted or not. More...
 
int InvokeEvent (const char *event, void *callData)
 
int InvokeEvent (unsigned long event)
 
int InvokeEvent (const char *event)
 
- Public Member Functions inherited from vtkObjectBase
const char * GetClassName () const
 Return the class name as a string. More...
 
virtual void Delete ()
 Delete a VTK object. More...
 
virtual void FastDelete ()
 Delete a reference to this object. More...
 
void InitializeObjectBase ()
 
void Print (ostream &os)
 Print an object to an ostream. More...
 
virtual void PrintHeader (ostream &os, vtkIndent indent)
 
virtual void PrintTrailer (ostream &os, vtkIndent indent)
 
virtual void Register (vtkObjectBase *o)
 Increase the reference count (mark as used by another object). More...
 
virtual void UnRegister (vtkObjectBase *o)
 Decrease the reference count (release by another object). More...
 
int GetReferenceCount ()
 Return the current reference count of this object. More...
 
void SetReferenceCount (int)
 Sets the reference count. More...
 
void PrintRevisions (ostream &)
 Legacy. More...
 

Static Public Member Functions

static vtkOpenGLInstanceCullingNew ()
 
static vtkTypeBool IsTypeOf (const char *type)
 
static vtkOpenGLInstanceCullingSafeDownCast (vtkObjectBase *o)
 
- Static Public Member Functions inherited from vtkObject
static vtkObjectNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 
static void BreakOnError ()
 This method is called when vtkErrorMacro executes. More...
 
static void SetGlobalWarningDisplay (int val)
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static void GlobalWarningDisplayOn ()
 
static void GlobalWarningDisplayOff ()
 
static int GetGlobalWarningDisplay ()
 
- Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool IsTypeOf (const char *name)
 Return 1 if this class type is the same type of (or a subclass of) the named class. More...
 
static vtkObjectBaseNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 

Protected Member Functions

virtual vtkObjectBaseNewInstanceInternal () const
 
 vtkOpenGLInstanceCulling ()=default
 
 ~vtkOpenGLInstanceCulling () override
 
void DeleteLODs ()
 
void UploadCurrentState (InstanceLOD &lod, vtkPolyData *pd)
 
- Protected Member Functions inherited from vtkObject
 vtkObject ()
 
 ~vtkObject () override
 
void RegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=nullptr)
 These methods allow a command to exclusively grab all events. More...
 
void InternalReleaseFocus ()
 
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
 
virtual ~vtkObjectBase ()
 
virtual void CollectRevisions (ostream &)
 
virtual void ReportReferences (vtkGarbageCollector *)
 
 vtkObjectBase (const vtkObjectBase &)
 
void operator= (const vtkObjectBase &)
 

Additional Inherited Members

- Protected Attributes inherited from vtkObject
bool Debug
 
vtkTimeStamp MTime
 
vtkSubjectHelper * SubjectHelper
 
- Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t > ReferenceCount
 
vtkWeakPointerBase ** WeakPointers
 

Detailed Description

Frustum culling and LOD management.

This class is used to cull instances based on their transformation matrix. It was designed to improve performances when there is large number of instances in vtkOpenGLGlyph3DMapper.

Each instance is tested on the GPU through vertex shader to know if it is inside of the frustum view. If it is, the distance to the camera is computed to select and send to the geometry shader the corresponding LOD index. The geometry shader register the instance to the corresponding vertex stream and therefore the corresponding transform feedback buffer in video memory.

Warning
GL_ARB_gpu_shader5 extension is required.
vtkIdType nbInstances = 1000000;
// buffer of size 16*nbInstances containing transform matrices.
vtkOpenGLBufferObject* bufferMatrix = ...;
// buffer of size 4*nbInstances containing color buffer to pass through.
vtkOpenGLBufferObject* bufferColor = ...;
// Initialize LODs
culling->InitLOD(polydata); // LOD0 : full geometry
culling->AddLOD(2.0, 0.5); // LOD1 : after 2.0, 50% triangles
culling->AddLOD(5.0, 0.99); // LOD2 : after 5.0, 1% triangles
// Build shader and binds
culling->BuildCullingShaders(ren, actor, nbInstances);
culling->RunCullingShaders(nbInstances, bufferMatrix, bufferColor);
// Get number of instances in LOD 0
int nbInstInLOD0 = culling->GetLOD(0).NumberOfInstances;
// Get VBO and IBO of LOD 1
vtkOpenGLBufferObject* IBO1 = culling->GetLOD(1).IBO;
// Get instances buffer of LOD 2
// buffer is interleaved [ transformMatrix0 color0 transformMatrix1 color1 ... ]
vtkOpenGLBufferObject* buffer2 = culling->GetLODBuffer(2);

Definition at line 81 of file vtkOpenGLInstanceCulling.h.

Member Typedef Documentation

◆ Superclass

Definition at line 85 of file vtkOpenGLInstanceCulling.h.

Constructor & Destructor Documentation

◆ vtkOpenGLInstanceCulling()

vtkOpenGLInstanceCulling::vtkOpenGLInstanceCulling ( )
protecteddefault

◆ ~vtkOpenGLInstanceCulling()

vtkOpenGLInstanceCulling::~vtkOpenGLInstanceCulling ( )
overrideprotected

Member Function Documentation

◆ New()

static vtkOpenGLInstanceCulling* vtkOpenGLInstanceCulling::New ( )
static

◆ IsTypeOf()

static vtkTypeBool vtkOpenGLInstanceCulling::IsTypeOf ( const char *  type)
static

◆ IsA()

virtual vtkTypeBool vtkOpenGLInstanceCulling::IsA ( const char *  name)
virtual

Return 1 if this class is the same type of (or a subclass of) the named class.

Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObjectBase.

◆ SafeDownCast()

static vtkOpenGLInstanceCulling* vtkOpenGLInstanceCulling::SafeDownCast ( vtkObjectBase o)
static

◆ NewInstanceInternal()

virtual vtkObjectBase* vtkOpenGLInstanceCulling::NewInstanceInternal ( ) const
protectedvirtual

◆ NewInstance()

vtkOpenGLInstanceCulling* vtkOpenGLInstanceCulling::NewInstance ( ) const

◆ InitLOD()

void vtkOpenGLInstanceCulling::InitLOD ( vtkPolyData pd)

Initialize LOD with a polydata.

◆ AddLOD()

void vtkOpenGLInstanceCulling::AddLOD ( float  distance,
float  targetReduction 
)

Add a level of detail.

distance is the distance after which LOD is enabled targetReduction is the reduction factor applied on polydata (vtkDecimatePro is used)

See also
vtkDecimatePro::SetTargetReduction

◆ BuildCullingShaders()

void vtkOpenGLInstanceCulling::BuildCullingShaders ( vtkOpenGLShaderCache cache,
vtkIdType  numInstances,
bool  withNormals 
)

Build culling shader program (if not created yet) and binds it.

◆ GetHelper()

vtkOpenGLHelper& vtkOpenGLInstanceCulling::GetHelper ( )

Get helper structure.

◆ GetLOD()

InstanceLOD& vtkOpenGLInstanceCulling::GetLOD ( vtkIdType  index)

Get LOD structure.

◆ GetNumberOfLOD()

vtkIdType vtkOpenGLInstanceCulling::GetNumberOfLOD ( )

Get number of LOD currently declared.

◆ GetLODBuffer()

vtkOpenGLBufferObject* vtkOpenGLInstanceCulling::GetLODBuffer ( vtkIdType  index)

Get the transform feedback buffer generated by the culling program.

◆ RunCullingShaders()

void vtkOpenGLInstanceCulling::RunCullingShaders ( vtkIdType  numInstances,
vtkOpenGLBufferObject matrixBuffer,
vtkOpenGLBufferObject colorBuffer,
vtkOpenGLBufferObject normalBuffer 
)

Run the culling program and generate LOD buffers.

◆ SetColorLOD()

virtual void vtkOpenGLInstanceCulling::SetColorLOD ( bool  )
virtual

Overload color with unique color per LOD.

◆ GetColorLOD()

virtual bool vtkOpenGLInstanceCulling::GetColorLOD ( )
virtual

◆ DeleteLODs()

void vtkOpenGLInstanceCulling::DeleteLODs ( )
protected

◆ UploadCurrentState()

void vtkOpenGLInstanceCulling::UploadCurrentState ( InstanceLOD lod,
vtkPolyData pd 
)
protected

The documentation for this class was generated from the following file:
vtkOpenGLBufferObject
OpenGL buffer object.
Definition: vtkOpenGLBufferObject.h:33
vtkOpenGLInstanceCulling::RunCullingShaders
void RunCullingShaders(vtkIdType numInstances, vtkOpenGLBufferObject *matrixBuffer, vtkOpenGLBufferObject *colorBuffer, vtkOpenGLBufferObject *normalBuffer)
Run the culling program and generate LOD buffers.
vtkIdType
int vtkIdType
Definition: vtkType.h:349
vtkOpenGLInstanceCulling::AddLOD
void AddLOD(float distance, float targetReduction)
Add a level of detail.
vtkOpenGLInstanceCulling::GetLOD
InstanceLOD & GetLOD(vtkIdType index)
Get LOD structure.
vtkOpenGLInstanceCulling::GetLODBuffer
vtkOpenGLBufferObject * GetLODBuffer(vtkIdType index)
Get the transform feedback buffer generated by the culling program.
vtkOpenGLInstanceCulling::BuildCullingShaders
void BuildCullingShaders(vtkOpenGLShaderCache *cache, vtkIdType numInstances, bool withNormals)
Build culling shader program (if not created yet) and binds it.
vtkNew< vtkOpenGLInstanceCulling >
vtkOpenGLInstanceCulling::InstanceLOD::PositionVBO
vtkOpenGLBufferObject * PositionVBO
Definition: vtkOpenGLInstanceCulling.h:92
vtkOpenGLInstanceCulling::InitLOD
void InitLOD(vtkPolyData *pd)
Initialize LOD with a polydata.
vtkOpenGLInstanceCulling::InstanceLOD::IBO
vtkOpenGLIndexBufferObject * IBO
Definition: vtkOpenGLInstanceCulling.h:91
vtkOpenGLInstanceCulling::InstanceLOD::NumberOfInstances
int NumberOfInstances
Definition: vtkOpenGLInstanceCulling.h:94