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vtkLineIntegralConvolution2D Class Reference

GPU-based implementation of Line Integral Convolution (LIC) More...

#include <vtkLineIntegralConvolution2D.h>

Inheritance diagram for vtkLineIntegralConvolution2D:
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Collaboration diagram for vtkLineIntegralConvolution2D:
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Public Types

enum  { ENHANCE_CONTRAST_OFF =0, ENHANCE_CONTRAST_ON =1 }
 Enable/Disable contrast and dynamic range correction stages. More...
 
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...
 
vtkLineIntegralConvolution2DNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
void SetContext (vtkOpenGLRenderWindow *context)
 Set/Get the rendering context. More...
 
vtkOpenGLRenderWindowGetContext ()
 
virtual void SetEnhancedLIC (int)
 EnhancedLIC mean compute the LIC twice with the second pass using the edge-enhanced result of the first pass as a noise texture. More...
 
virtual int GetEnhancedLIC ()
 
virtual void EnhancedLICOn ()
 
virtual void EnhancedLICOff ()
 
virtual void SetEnhanceContrast (int)
 
virtual int GetEnhanceContrast ()
 
virtual void EnhanceContrastOn ()
 
virtual void EnhanceContrastOff ()
 
virtual void SetLowContrastEnhancementFactor (double)
 This feature is used to fine tune the contrast enhancement. More...
 
virtual double GetLowContrastEnhancementFactor ()
 
virtual void SetHighContrastEnhancementFactor (double)
 
virtual double GetHighContrastEnhancementFactor ()
 
virtual void SetAntiAlias (int)
 Enable/Disable the anti-aliasing pass. More...
 
virtual int GetAntiAlias ()
 
virtual void AntiAliasOn ()
 
virtual void AntiAliasOff ()
 
virtual void SetNumberOfSteps (int)
 Number of streamline integration steps (initial value is 1). More...
 
virtual int GetNumberOfSteps ()
 
virtual void SetStepSize (double)
 Get/Set the streamline integration step size (0.01 by default). More...
 
virtual double GetStepSize ()
 
void SetComponentIds (int c0, int c1)
 If VectorField has >= 3 components, we must choose which 2 components form the (X, Y) components for the vector field. More...
 
void SetComponentIds (int c[2])
 
virtual intGetComponentIds ()
 
virtual void GetComponentIds (int &, int &)
 
virtual void GetComponentIds (int[2])
 
virtual void SetMaxNoiseValue (double)
 Set the max noise value for use during LIC integration normalization. More...
 
virtual double GetMaxNoiseValue ()
 
void SetTransformVectors (int val)
 This class performs LIC in the normalized image space. More...
 
virtual int GetTransformVectors ()
 
void SetNormalizeVectors (int val)
 Set/Get the spacing in each dimension of the plane on which the vector field is defined. More...
 
virtual int GetNormalizeVectors ()
 
virtual void SetMaskThreshold (double)
 The MaskThreshold controls blanking of the LIC texture. More...
 
virtual double GetMaskThreshold ()
 
vtkTextureObjectExecute (vtkTextureObject *vectorTex, vtkTextureObject *noiseTex)
 Compute the lic on the entire vector field texture. More...
 
vtkTextureObjectExecute (const int extent[4], vtkTextureObject *vectorTex, vtkTextureObject *noiseTex)
 Compute the lic on the indicated subset of the vector field texture. More...
 
vtkTextureObjectExecute (const vtkPixelExtent &inputTexExtent, const std::deque< vtkPixelExtent > &vectorExtent, const std::deque< vtkPixelExtent > &licExtent, vtkTextureObject *vectorTex, vtkTextureObject *maskVectorTex, vtkTextureObject *noiseTex)
 Compute LIC over the desired subset of the input texture. More...
 
virtual void SetCommunicator (vtkPainterCommunicator *)
 Set the communicator to use during parallel operation The communicator will not be duplicated or reference counted for performance reasons thus caller should hold/manage reference to the communicator during use of the LIC object. More...
 
virtual vtkPainterCommunicatorGetCommunicator ()
 
virtual void GetGlobalMinMax (vtkPainterCommunicator *, float &, float &)
 For parallel operation, find global min/max min/max are in/out. More...
 
virtual void WriteTimerLog (const char *)
 Methods used for parallel benchmarks. More...
 
- 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...
 
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 vtkLineIntegralConvolution2DNew ()
 
static vtkTypeBool IsTypeOf (const char *type)
 
static vtkLineIntegralConvolution2DSafeDownCast (vtkObjectBase *o)
 
static bool IsSupported (vtkRenderWindow *renWin)
 Returns if the context supports the required extensions. More...
 
static void SetVectorTexParameters (vtkTextureObject *vectors)
 Convenience functions to ensure that the input textures are configured correctly. More...
 
static void SetNoiseTexParameters (vtkTextureObject *noise)
 
- 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
 
 vtkLineIntegralConvolution2D ()
 
 ~vtkLineIntegralConvolution2D () override
 
void SetVTShader (vtkShaderProgram *prog)
 
void SetLIC0Shader (vtkShaderProgram *prog)
 
void SetLICIShader (vtkShaderProgram *prog)
 
void SetLICNShader (vtkShaderProgram *prog)
 
void SetEEShader (vtkShaderProgram *prog)
 
void SetCEShader (vtkShaderProgram *prog)
 
void SetAAHShader (vtkShaderProgram *prog)
 
void SetAAVShader (vtkShaderProgram *prog)
 
void BuildShaders ()
 
void RenderQuad (float computeBounds[4], vtkPixelExtent computeExtent)
 
vtkTextureObjectAllocateBuffer (unsigned int texSize[2])
 
void SetNoise2TexParameters (vtkTextureObject *noise)
 Convenience functions to ensure that the input textures are configured correctly. More...
 
virtual void StartTimerEvent (const char *)
 Methods used for parallel benchmarks. More...
 
virtual void EndTimerEvent (const char *)
 
- 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 &)
 

Protected Attributes

vtkPainterCommunicatorComm
 
vtkWeakPointer< vtkOpenGLRenderWindowContext
 
vtkOpenGLFramebufferObjectFBO
 
int ShadersNeedBuild
 
vtkOpenGLHelperFinalBlendProgram
 
vtkOpenGLHelperIntermediateBlendProgram
 
vtkOpenGLHelperVTShader
 
vtkOpenGLHelperLIC0Shader
 
vtkOpenGLHelperLICIShader
 
vtkOpenGLHelperLICNShader
 
vtkOpenGLHelperEEShader
 
vtkOpenGLHelperCEShader
 
vtkOpenGLHelperAAHShader
 
vtkOpenGLHelperAAVShader
 
int NumberOfSteps
 
double StepSize
 
int EnhancedLIC
 
int EnhanceContrast
 
double LowContrastEnhancementFactor
 
double HighContrastEnhancementFactor
 
int AntiAlias
 
int NoiseTextureLookupCompatibilityMode
 
double MaskThreshold
 
int TransformVectors
 
int NormalizeVectors
 
int ComponentIds [2]
 
double MaxNoiseValue
 
- 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

GPU-based implementation of Line Integral Convolution (LIC)

This class resorts to GLSL to implement GPU-based Line Integral Convolution (LIC) for visualizing a 2D vector field that may be obtained by projecting an original 3D vector field onto a surface (such that the resulting 2D vector at each grid point on the surface is tangential to the local normal, as done in vtkSurfaceLICPainter).

As an image-based technique, 2D LIC works by (1) integrating a bidirectional streamline from the center of each pixel (of the LIC output image), (2) locating the pixels along / hit by this streamline as the correlated pixels of the starting pixel (seed point / pixel), (3) indexing a (usually white) noise texture (another input to LIC, in addition to the 2D vector field, usually with the same size as that of the 2D vetor field) to determine the values (colors) of these pixels (the starting and the correlated pixels), typically through bi-linear interpolation, and (4) performing convolution (weighted averaging) on these values, by adopting a low-pass filter (such as box, ramp, and Hanning kernels), to obtain the result value (color) that is then assigned to the seed pixel.

The GLSL-based GPU implementation herein maps the aforementioned pipeline to fragment shaders and a box kernel is employed. Both the white noise and the vector field are provided to the GPU as texture objects (supported by the multi-texturing capability). In addition, there are four texture objects (color buffers) allocated to constitute two pairs that work in a ping-pong fashion, with one as the read buffers and the other as the write / render targets. Maintained by a frame buffer object (GL_EXT_framebuffer_object), each pair employs one buffer to store the current (dynamically updated) position (by means of the texture coordinate that keeps being warped by the underlying vector) of the (virtual) particle initially released from each fragment while using the bother buffer to store the current (dynamically updated too) accumulated texture value that each seed fragment (before the 'mesh' is warped) collects. Given NumberOfSteps integration steps in each direction, there are a total of (2 * NumberOfSteps + 1) fragments (including the seed fragment) are convolved and each contributes 1 / (2 * NumberOfSteps

One pass of LIC (basic LIC) tends to produce low-contrast / blurred images and vtkLineIntegralConvolution2D provides an option for creating enhanced LIC images. Enhanced LIC improves image quality by increasing inter-streamline contrast while suppressing artifacts. It performs two passes of LIC, with a 3x3 Laplacian high-pass filter in between that processes the output of pass #1 LIC and forwards the result as the input 'noise' to pass #2 LIC.

vtkLineIntegralConvolution2D applies masking to zero-vector fragments so that un-filtered white noise areas are made totally transparent by class vtkSurfaceLICPainter to show the underlying geometry surface.

The convolution process tends to decrease both contrast and dynamic range, sometimes leading to dull dark images. In order to counteract this, optional contrast ehnancement stages have been added. These increase the dynamic range and contrast and sharpen streaking patterns that emerge from the LIC process.

Under some circumstances, typically depending on the contrast and dynamic range and graininess of the noise texture, jagged or pixelated patterns emerge in the LIC. These can be reduced by enabling the optional anti-aliasing pass.

The internal pipeline is as follows, with optional stages denoted by () nested optional stages depend on their parent stage.

  noise texture
          |
          [ LIC ((CE) HPF LIC) (AA) (CE) ]
          |                              |
 vector field                       LIC'd image

where LIC is the LIC stage, HPF is the high-pass filter stage, CE is the contrast ehnacement stage, and AA is the antialias stage.

See also
vtkImageDataLIC2D vtkStructuredGridLIC2D

Definition at line 109 of file vtkLineIntegralConvolution2D.h.

Member Typedef Documentation

◆ Superclass

Definition at line 113 of file vtkLineIntegralConvolution2D.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enable/Disable contrast and dynamic range correction stages.

Stage 1 is applied on the input to the high-pass filter when the high-pass filter is enabled and skipped otherwise. Stage 2, when enabled is the final stage in the internal pipeline. Both stages are implemented by a histogram stretching of the gray scale colors in the LIC'd image as follows:

c = (c-m)/(M-m)

where, c is the fragment color, m is the color value to map to 0, M is the color value to map to 1. The default values of m and M are the min and max over all fragments.

This increase the dynamic range and contrast in the LIC'd image, both of which are naturally attenuated by the LI convolution process.

ENHANCE_CONTRAST_OFF – don't enhance contrast ENHANCE_CONTRAST_ON – enhance high-pass input and final stage output

This feature is disabled by default.

Enumerator
ENHANCE_CONTRAST_OFF 
ENHANCE_CONTRAST_ON 

Definition at line 163 of file vtkLineIntegralConvolution2D.h.

Constructor & Destructor Documentation

◆ vtkLineIntegralConvolution2D()

vtkLineIntegralConvolution2D::vtkLineIntegralConvolution2D ( )
protected

◆ ~vtkLineIntegralConvolution2D()

vtkLineIntegralConvolution2D::~vtkLineIntegralConvolution2D ( )
overrideprotected

Member Function Documentation

◆ New()

static vtkLineIntegralConvolution2D* vtkLineIntegralConvolution2D::New ( )
static

◆ IsTypeOf()

static vtkTypeBool vtkLineIntegralConvolution2D::IsTypeOf ( const char *  type)
static

◆ IsA()

virtual vtkTypeBool vtkLineIntegralConvolution2D::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.

Reimplemented in vtkPLineIntegralConvolution2D.

◆ SafeDownCast()

static vtkLineIntegralConvolution2D* vtkLineIntegralConvolution2D::SafeDownCast ( vtkObjectBase o)
static

◆ NewInstanceInternal()

virtual vtkObjectBase* vtkLineIntegralConvolution2D::NewInstanceInternal ( ) const
protectedvirtual

Reimplemented in vtkPLineIntegralConvolution2D.

◆ NewInstance()

vtkLineIntegralConvolution2D* vtkLineIntegralConvolution2D::NewInstance ( ) const

◆ PrintSelf()

void vtkLineIntegralConvolution2D::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
overridevirtual

Methods invoked by print to print information about the object including superclasses.

Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

Reimplemented in vtkPLineIntegralConvolution2D.

◆ IsSupported()

static bool vtkLineIntegralConvolution2D::IsSupported ( vtkRenderWindow renWin)
static

Returns if the context supports the required extensions.

◆ SetContext()

void vtkLineIntegralConvolution2D::SetContext ( vtkOpenGLRenderWindow context)

Set/Get the rendering context.

A reference is not explicitly held, thus reference to the context must be held externally.

◆ GetContext()

vtkOpenGLRenderWindow* vtkLineIntegralConvolution2D::GetContext ( )

◆ SetEnhancedLIC()

virtual void vtkLineIntegralConvolution2D::SetEnhancedLIC ( int  )
virtual

EnhancedLIC mean compute the LIC twice with the second pass using the edge-enhanced result of the first pass as a noise texture.

Edge enhancedment is made by a simple Laplace convolution.

◆ GetEnhancedLIC()

virtual int vtkLineIntegralConvolution2D::GetEnhancedLIC ( )
virtual

◆ EnhancedLICOn()

virtual void vtkLineIntegralConvolution2D::EnhancedLICOn ( )
virtual

◆ EnhancedLICOff()

virtual void vtkLineIntegralConvolution2D::EnhancedLICOff ( )
virtual

◆ SetEnhanceContrast()

virtual void vtkLineIntegralConvolution2D::SetEnhanceContrast ( int  )
virtual

◆ GetEnhanceContrast()

virtual int vtkLineIntegralConvolution2D::GetEnhanceContrast ( )
virtual

◆ EnhanceContrastOn()

virtual void vtkLineIntegralConvolution2D::EnhanceContrastOn ( )
virtual

◆ EnhanceContrastOff()

virtual void vtkLineIntegralConvolution2D::EnhanceContrastOff ( )
virtual

◆ SetLowContrastEnhancementFactor()

virtual void vtkLineIntegralConvolution2D::SetLowContrastEnhancementFactor ( double  )
virtual

This feature is used to fine tune the contrast enhancement.

Values are provided indicating the fraction of the range to adjust m and M by during contrast enahncement histogram stretching. M and m are the intensity/lightness values that map to 1 and 0. (see EnhanceContrast for an explanation of the mapping procedure). m and M are computed using the factors as follows:

m = min(C) - mFactor * (max(C) - min(C)) M = max(C) - MFactor * (max(C) - min(C))

the default values for mFactor and MFactor are 0 which result in m = min(C), M = max(C), where C is all of the colors in the image. Adjusting mFactor and MFactor above zero provide a means to control the saturation of normalization. These settings only affect the final normalization, the normalization that occurs on the input to the high-pass filter always uses the min and max.

◆ GetLowContrastEnhancementFactor()

virtual double vtkLineIntegralConvolution2D::GetLowContrastEnhancementFactor ( )
virtual

◆ SetHighContrastEnhancementFactor()

virtual void vtkLineIntegralConvolution2D::SetHighContrastEnhancementFactor ( double  )
virtual

◆ GetHighContrastEnhancementFactor()

virtual double vtkLineIntegralConvolution2D::GetHighContrastEnhancementFactor ( )
virtual

◆ SetAntiAlias()

virtual void vtkLineIntegralConvolution2D::SetAntiAlias ( int  )
virtual

Enable/Disable the anti-aliasing pass.

This optional pass (disabled by default) can be enabled to reduce jagged patterns in the final LIC image. Values greater than 0 control the number of iterations, one is typically sufficient.

◆ GetAntiAlias()

virtual int vtkLineIntegralConvolution2D::GetAntiAlias ( )
virtual

◆ AntiAliasOn()

virtual void vtkLineIntegralConvolution2D::AntiAliasOn ( )
virtual

◆ AntiAliasOff()

virtual void vtkLineIntegralConvolution2D::AntiAliasOff ( )
virtual

◆ SetNumberOfSteps()

virtual void vtkLineIntegralConvolution2D::SetNumberOfSteps ( int  )
virtual

Number of streamline integration steps (initial value is 1).

In term of visual quality, the greater (within some range) the better.

◆ GetNumberOfSteps()

virtual int vtkLineIntegralConvolution2D::GetNumberOfSteps ( )
virtual

◆ SetStepSize()

virtual void vtkLineIntegralConvolution2D::SetStepSize ( double  )
virtual

Get/Set the streamline integration step size (0.01 by default).

This is the length of each step in normalized image space i.e. in range [0, FLOAT_MAX]. In term of visual quality, the smaller the better. The type for the interface is double as VTK interface is, but GPU only supports float. Thus it will be converted to float in the execution of the algorithm.

◆ GetStepSize()

virtual double vtkLineIntegralConvolution2D::GetStepSize ( )
virtual

◆ SetComponentIds() [1/2]

void vtkLineIntegralConvolution2D::SetComponentIds ( int  c0,
int  c1 
)

If VectorField has >= 3 components, we must choose which 2 components form the (X, Y) components for the vector field.

Must be in the range [0, 3].

◆ SetComponentIds() [2/2]

void vtkLineIntegralConvolution2D::SetComponentIds ( int  c[2])
inline

Definition at line 235 of file vtkLineIntegralConvolution2D.h.

◆ GetComponentIds() [1/3]

virtual int* vtkLineIntegralConvolution2D::GetComponentIds ( )
virtual

◆ GetComponentIds() [2/3]

virtual void vtkLineIntegralConvolution2D::GetComponentIds ( int ,
int  
)
virtual

◆ GetComponentIds() [3/3]

virtual void vtkLineIntegralConvolution2D::GetComponentIds ( int  [2])
virtual

◆ SetMaxNoiseValue()

virtual void vtkLineIntegralConvolution2D::SetMaxNoiseValue ( double  )
virtual

Set the max noise value for use during LIC integration normalization.

The integration normalization factor is the max noise value times the number of steps taken. The default value is 1.

◆ GetMaxNoiseValue()

virtual double vtkLineIntegralConvolution2D::GetMaxNoiseValue ( )
virtual

◆ SetTransformVectors()

void vtkLineIntegralConvolution2D::SetTransformVectors ( int  val)

This class performs LIC in the normalized image space.

Hence, by default it transforms the input vectors to the normalized image space (using the GridSpacings and input vector field dimensions). Set this to 0 to disable transformation if the vectors are already transformed.

◆ GetTransformVectors()

virtual int vtkLineIntegralConvolution2D::GetTransformVectors ( )
virtual

◆ SetNormalizeVectors()

void vtkLineIntegralConvolution2D::SetNormalizeVectors ( int  val)

Set/Get the spacing in each dimension of the plane on which the vector field is defined.

This class performs LIC in the normalized image space and hence generally it needs to transform the input vector field (given in physical space) to the normalized image space. The Spacing is needed to determine the transform. Default is (1.0, 1.0). It is possible to disable vector transformation by setting TransformVectors to 0. vtkSetVector2Macro(GridSpacings, double); vtkGetVector2Macro(GridSpacings, double); Normalize vectors during integration. When set(the default) the input vector field is normalized during integration, and each integration occurs over the same arclength. When not set each integration occurs over an arc length proportional to the field magnitude as is customary in traditional numerical methods. See, "Imaging Vector Fields Using Line Integral Convolution" for an axample where normalization is used. See, "Image Space Based Visualization of Unsteady Flow on Surfaces" for an example of where no normalization is used.

◆ GetNormalizeVectors()

virtual int vtkLineIntegralConvolution2D::GetNormalizeVectors ( )
virtual

◆ SetMaskThreshold()

virtual void vtkLineIntegralConvolution2D::SetMaskThreshold ( double  )
virtual

The MaskThreshold controls blanking of the LIC texture.

For fragments with |V|<threshold the LIC fragment is not rendered. The default value is 0.0.

For surface LIC MaskThreshold units are in the original vector space. For image LIC be aware that while the vector field is transformed to image space while the mask threshold is not. Therefore the mask threshold must be specified in image space units.

◆ GetMaskThreshold()

virtual double vtkLineIntegralConvolution2D::GetMaskThreshold ( )
virtual

◆ Execute() [1/3]

vtkTextureObject* vtkLineIntegralConvolution2D::Execute ( vtkTextureObject vectorTex,
vtkTextureObject noiseTex 
)

Compute the lic on the entire vector field texture.

◆ Execute() [2/3]

vtkTextureObject* vtkLineIntegralConvolution2D::Execute ( const int  extent[4],
vtkTextureObject vectorTex,
vtkTextureObject noiseTex 
)

Compute the lic on the indicated subset of the vector field texture.

◆ Execute() [3/3]

vtkTextureObject* vtkLineIntegralConvolution2D::Execute ( const vtkPixelExtent inputTexExtent,
const std::deque< vtkPixelExtent > &  vectorExtent,
const std::deque< vtkPixelExtent > &  licExtent,
vtkTextureObject vectorTex,
vtkTextureObject maskVectorTex,
vtkTextureObject noiseTex 
)

Compute LIC over the desired subset of the input texture.

The result is copied into the desired subset of the provided output texture.

inputTexExtent : screen space extent of the input texture vectorExtent : part of the inpute extent that has valid vectors licExtent : part of the inpute extent to compute on outputTexExtent : screen space extent of the output texture outputExtent : part of the output texture to store the result

◆ SetVectorTexParameters()

static void vtkLineIntegralConvolution2D::SetVectorTexParameters ( vtkTextureObject vectors)
static

Convenience functions to ensure that the input textures are configured correctly.

◆ SetNoiseTexParameters()

static void vtkLineIntegralConvolution2D::SetNoiseTexParameters ( vtkTextureObject noise)
static

◆ SetCommunicator()

virtual void vtkLineIntegralConvolution2D::SetCommunicator ( vtkPainterCommunicator )
inlinevirtual

Set the communicator to use during parallel operation The communicator will not be duplicated or reference counted for performance reasons thus caller should hold/manage reference to the communicator during use of the LIC object.

Reimplemented in vtkPLineIntegralConvolution2D.

Definition at line 352 of file vtkLineIntegralConvolution2D.h.

◆ GetCommunicator()

virtual vtkPainterCommunicator* vtkLineIntegralConvolution2D::GetCommunicator ( )
virtual

Reimplemented in vtkPLineIntegralConvolution2D.

◆ GetGlobalMinMax()

virtual void vtkLineIntegralConvolution2D::GetGlobalMinMax ( vtkPainterCommunicator ,
float ,
float  
)
inlinevirtual

For parallel operation, find global min/max min/max are in/out.

Reimplemented in vtkPLineIntegralConvolution2D.

Definition at line 359 of file vtkLineIntegralConvolution2D.h.

◆ WriteTimerLog()

virtual void vtkLineIntegralConvolution2D::WriteTimerLog ( const char *  )
inlinevirtual

Methods used for parallel benchmarks.

Use cmake to define vtkLineIntegralConviolution2DTIME to enable benchmarks. During each update timing information is stored, it can be written to disk by calling WriteLog.

Reimplemented in vtkPLineIntegralConvolution2D.

Definition at line 370 of file vtkLineIntegralConvolution2D.h.

◆ SetVTShader()

void vtkLineIntegralConvolution2D::SetVTShader ( vtkShaderProgram prog)
protected

◆ SetLIC0Shader()

void vtkLineIntegralConvolution2D::SetLIC0Shader ( vtkShaderProgram prog)
protected

◆ SetLICIShader()

void vtkLineIntegralConvolution2D::SetLICIShader ( vtkShaderProgram prog)
protected

◆ SetLICNShader()

void vtkLineIntegralConvolution2D::SetLICNShader ( vtkShaderProgram prog)
protected

◆ SetEEShader()

void vtkLineIntegralConvolution2D::SetEEShader ( vtkShaderProgram prog)
protected

◆ SetCEShader()

void vtkLineIntegralConvolution2D::SetCEShader ( vtkShaderProgram prog)
protected

◆ SetAAHShader()

void vtkLineIntegralConvolution2D::SetAAHShader ( vtkShaderProgram prog)
protected

◆ SetAAVShader()

void vtkLineIntegralConvolution2D::SetAAVShader ( vtkShaderProgram prog)
protected

◆ BuildShaders()

void vtkLineIntegralConvolution2D::BuildShaders ( )
protected

◆ RenderQuad()

void vtkLineIntegralConvolution2D::RenderQuad ( float  computeBounds[4],
vtkPixelExtent  computeExtent 
)
protected

◆ AllocateBuffer()

vtkTextureObject* vtkLineIntegralConvolution2D::AllocateBuffer ( unsigned int  texSize[2])
protected

◆ SetNoise2TexParameters()

void vtkLineIntegralConvolution2D::SetNoise2TexParameters ( vtkTextureObject noise)
protected

Convenience functions to ensure that the input textures are configured correctly.

◆ StartTimerEvent()

virtual void vtkLineIntegralConvolution2D::StartTimerEvent ( const char *  )
inlineprotectedvirtual

Methods used for parallel benchmarks.

Use cmake to define vtkSurfaceLICPainterTIME to enable benchmarks. During each update timing information is stored, it can be written to disk by calling WriteLog (defined in vtkSurfaceLICPainter).

Reimplemented in vtkPLineIntegralConvolution2D.

Definition at line 407 of file vtkLineIntegralConvolution2D.h.

◆ EndTimerEvent()

virtual void vtkLineIntegralConvolution2D::EndTimerEvent ( const char *  )
inlineprotectedvirtual

Reimplemented in vtkPLineIntegralConvolution2D.

Definition at line 408 of file vtkLineIntegralConvolution2D.h.

Member Data Documentation

◆ Comm

vtkPainterCommunicator* vtkLineIntegralConvolution2D::Comm
protected

Definition at line 376 of file vtkLineIntegralConvolution2D.h.

◆ Context

vtkWeakPointer<vtkOpenGLRenderWindow> vtkLineIntegralConvolution2D::Context
protected

Definition at line 411 of file vtkLineIntegralConvolution2D.h.

◆ FBO

vtkOpenGLFramebufferObject* vtkLineIntegralConvolution2D::FBO
protected

Definition at line 412 of file vtkLineIntegralConvolution2D.h.

◆ ShadersNeedBuild

int vtkLineIntegralConvolution2D::ShadersNeedBuild
protected

Definition at line 414 of file vtkLineIntegralConvolution2D.h.

◆ FinalBlendProgram

vtkOpenGLHelper* vtkLineIntegralConvolution2D::FinalBlendProgram
protected

Definition at line 415 of file vtkLineIntegralConvolution2D.h.

◆ IntermediateBlendProgram

vtkOpenGLHelper* vtkLineIntegralConvolution2D::IntermediateBlendProgram
protected

Definition at line 416 of file vtkLineIntegralConvolution2D.h.

◆ VTShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::VTShader
protected

Definition at line 417 of file vtkLineIntegralConvolution2D.h.

◆ LIC0Shader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::LIC0Shader
protected

Definition at line 418 of file vtkLineIntegralConvolution2D.h.

◆ LICIShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::LICIShader
protected

Definition at line 419 of file vtkLineIntegralConvolution2D.h.

◆ LICNShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::LICNShader
protected

Definition at line 420 of file vtkLineIntegralConvolution2D.h.

◆ EEShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::EEShader
protected

Definition at line 421 of file vtkLineIntegralConvolution2D.h.

◆ CEShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::CEShader
protected

Definition at line 422 of file vtkLineIntegralConvolution2D.h.

◆ AAHShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::AAHShader
protected

Definition at line 423 of file vtkLineIntegralConvolution2D.h.

◆ AAVShader

vtkOpenGLHelper* vtkLineIntegralConvolution2D::AAVShader
protected

Definition at line 424 of file vtkLineIntegralConvolution2D.h.

◆ NumberOfSteps

int vtkLineIntegralConvolution2D::NumberOfSteps
protected

Definition at line 426 of file vtkLineIntegralConvolution2D.h.

◆ StepSize

double vtkLineIntegralConvolution2D::StepSize
protected

Definition at line 427 of file vtkLineIntegralConvolution2D.h.

◆ EnhancedLIC

int vtkLineIntegralConvolution2D::EnhancedLIC
protected

Definition at line 428 of file vtkLineIntegralConvolution2D.h.

◆ EnhanceContrast

int vtkLineIntegralConvolution2D::EnhanceContrast
protected

Definition at line 429 of file vtkLineIntegralConvolution2D.h.

◆ LowContrastEnhancementFactor

double vtkLineIntegralConvolution2D::LowContrastEnhancementFactor
protected

Definition at line 430 of file vtkLineIntegralConvolution2D.h.

◆ HighContrastEnhancementFactor

double vtkLineIntegralConvolution2D::HighContrastEnhancementFactor
protected

Definition at line 431 of file vtkLineIntegralConvolution2D.h.

◆ AntiAlias

int vtkLineIntegralConvolution2D::AntiAlias
protected

Definition at line 432 of file vtkLineIntegralConvolution2D.h.

◆ NoiseTextureLookupCompatibilityMode

int vtkLineIntegralConvolution2D::NoiseTextureLookupCompatibilityMode
protected

Definition at line 433 of file vtkLineIntegralConvolution2D.h.

◆ MaskThreshold

double vtkLineIntegralConvolution2D::MaskThreshold
protected

Definition at line 434 of file vtkLineIntegralConvolution2D.h.

◆ TransformVectors

int vtkLineIntegralConvolution2D::TransformVectors
protected

Definition at line 435 of file vtkLineIntegralConvolution2D.h.

◆ NormalizeVectors

int vtkLineIntegralConvolution2D::NormalizeVectors
protected

Definition at line 436 of file vtkLineIntegralConvolution2D.h.

◆ ComponentIds

int vtkLineIntegralConvolution2D::ComponentIds[2]
protected

Definition at line 437 of file vtkLineIntegralConvolution2D.h.

◆ MaxNoiseValue

double vtkLineIntegralConvolution2D::MaxNoiseValue
protected

Definition at line 438 of file vtkLineIntegralConvolution2D.h.


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