Heightfield rendering widget based on sphere-tracing. More...

#include <realtime.h>

Public Member Functions
	TerrainRaytracingWidget (QWidget *=nullptr)
	Default constructor.
	~TerrainRaytracingWidget ()
	Destructor. Release shader program, vao and textures.
virtual void	SetHeightField (ScalarField2 *)
	Internal update function of the widget.
virtual void	UpdateInternal ()
	Update the GPU data from the internal CPU heightfield pointer.
void	UpdateBuffer (GLuint)
	Manually change the underlying heightfield buffer.
void	SetShading (const ScalarField2 &)
	Set the additional shading buffer that can be used by the glsl.
void	UseShading (bool=true)
	Set the additional shading flag.
void	SetExternAlbedo (GLuint)
	Update the albedo texture with an existing OpenGL texture.
void	UseExternAlbedo (bool=true)
	Update the albedo texture flag.
void	SetAlbedo (const QImage &)
	Update the albedo texture. UseAlbedo(true) should have been called before, or no update will be performed.
void	UseAlbedo (bool=true)
	Update the internal albedo texture flag.
void	UseWireframe (bool=true)
	Set the wireframe flag.
void	UseCost (bool=true)
	Set the cost shading flag.
void	UseElevationShading (bool)
	Set the elevation shading flag.
void	UseGreenBrownYellowShading (bool)
	Set the shading from color map flag.
void	SetCamera (const Camera &)
	Function override from AbstractTerrainWidget.
void	Reload ()
	Hot reload of the glsl program. Properly rebinds the albedo texture.
void	SetElevationRange (double, double)
	Set the elevation range for the terrain.
void	SetSteps (int)
	Set the maximum number of raymarching step.
void	SetEpsilon (float)
	Set the minimum stepping distance for raymarching.
void	SetLight (const Vector &)
	Set the directional light.
void	SetAntialiasing (int)
	Set the amount of antialiasing.
void	ShowSides (bool)
	Chooses to show terrain sides.
void	ShowUnderside (bool)
	Chooses to show terrain undersides.
void	UseSmoothShadow (bool=true)
	Set the smooth shadow flag.
void	SetSmoothShadowSteps (int)
	Set the number of smooth shadow steps.
void	SetSmoothShadowMarchingSteps (int)
	Set the maximum number of smooth shadow raymarching steps.
void	SetSmoothShadowMarchingEpsilon (float)
	Set the minimum marching epsilon for smooth shadow rays.
void	SetSmoothShadowStrength (float)
	Set the smooth shadow strength.
void	UseSelfShadow (bool=true)
	Set the smooth shadow flag.
void	SetSelfShadowMarchingSteps (int)
	Set the maximum number of self shadow raymarching steps.
void	SetSelfShadowMarchingEpsilon (float)
	Set the minimum marching epsilon for self shadow rays.
void	SetSelfShadowStrength (float)
	Set the self shadow strength.

Protected Member Functions
virtual void	paintGL ()
	Renders the scene.
virtual void	initializeGL ()
	Initialize OpenGL, shaders and a camera centered at origin.
virtual void	ReloadShaders ()
	Reload the shaders of the widget. Useful for realtime editing and fine tuning of the rendering.

Protected Attributes
ScalarField2 *	sf = nullptr
	Pointer to heightfield.
Box2	bbox
	Bounding box of the heightfield.
float	zMax = 0.0
	Min/max elevation of the heighfield.
float	K = 1.0
	Global Lipschitz constant of the heightfield.
int	ny = 0
	Grid sizes.
GLuint	shaderProgram = 0
	GL program for shader.
GLuint	raytraceVAO = 0
	Raytracer VAO.
GLBuffer	hfBuffer
	Heightfield elevation buffer.
GLBuffer	shadingBuffer
	Shading buffer.
std::vector< float >	tmpData
	Temporary float vector.
GLuint	albedoTextureBuffer = 0
	Albedo texture buffer.
GLuint	externAlbedo = 0
	Extern albedo texture buffer.
bool	useAlbedo = false
	Albedo texture flag.
bool	useWireframe = false
	Wireframe flag.
bool	useCost = false
	Cost shading flag.
bool	useElevationShading = false
	Elevation shading flag.
bool	useGreenBrownYellow = false
	Shading from color map flag.
bool	useShadingBuffer = false
	Additional shading buffer use flag.
bool	show_sides = true
	Flag for showing sides of the terrain.
bool	show_under = false
	Flag for showing the underside of the terrain.

Detailed Description

Heightfield rendering widget based on sphere-tracing.

Member Function Documentation

◆ SetAlbedo()

void TerrainRaytracingWidget::SetAlbedo ( const QImage & albedo )

Update the albedo texture. UseAlbedo(true) should have been called before, or no update will be performed.

Parameters

albedo texture

References albedoTextureBuffer, sf, and shaderProgram.

◆ SetAntialiasing()

void TerrainRaytracingWidget::SetAntialiasing ( int AA )

Set the amount of antialiasing.

Parameters

AA	antialiasing, should be between [1, 128].

References shaderProgram.

◆ SetCamera()

void TerrainRaytracingWidget::SetCamera ( const Camera & cam )

Function override from AbstractTerrainWidget.

Used to store the camera vertical angle of view, which avoids calling atan() intensively.

Parameters

cam	new camera

◆ SetElevationRange()

void TerrainRaytracingWidget::SetElevationRange	(	double	min,
		double	max )

Set the elevation range for the terrain.

Parameters

min,max elevation range

References zMax.

◆ SetEpsilon()

void TerrainRaytracingWidget::SetEpsilon ( float eps )

Set the minimum stepping distance for raymarching.

Parameters

eps	minimum stepping distance

References shaderProgram.

◆ SetExternAlbedo()

void TerrainRaytracingWidget::SetExternAlbedo ( GLuint texture )

Update the albedo texture with an existing OpenGL texture.

UseAlbedo(true) should have been called before, or no update will be performed.

Parameters

texture Texture.

References externAlbedo, sf, and shaderProgram.

◆ SetHeightField()

void TerrainRaytracingWidget::SetHeightField ( ScalarField2 * sfPtr )

virtual

Internal update function of the widget.

Updates the internal height buffer from the heightfield pointer, recomputes the Lipschitz constant and min/max elevations.

References sf, and UpdateInternal().

◆ SetLight()

void TerrainRaytracingWidget::SetLight ( const Vector & light )

Set the directional light.

Parameters

light light direction

References shaderProgram, and VectorFloat::z.

◆ SetSelfShadowMarchingEpsilon()

void TerrainRaytracingWidget::SetSelfShadowMarchingEpsilon ( float eps )

Set the minimum marching epsilon for self shadow rays.

Parameters

eps	marching epsilon

References shaderProgram.

◆ SetSelfShadowMarchingSteps()

void TerrainRaytracingWidget::SetSelfShadowMarchingSteps ( int steps )

Set the maximum number of self shadow raymarching steps.

Parameters

steps max number of steps

References shaderProgram.

◆ SetSelfShadowStrength()

void TerrainRaytracingWidget::SetSelfShadowStrength ( float strength )

Set the self shadow strength.

Parameters

strength

References shaderProgram.

◆ SetShading()

void TerrainRaytracingWidget::SetShading ( const ScalarField2 & shading )

Set the additional shading buffer that can be used by the glsl.

Parameters

shading 2D shading map, must be the same size as the underlying heightfield.

References ScalarField2::at(), sf, shadingBuffer, and tmpData.

◆ SetSmoothShadowMarchingEpsilon()

void TerrainRaytracingWidget::SetSmoothShadowMarchingEpsilon ( float eps )

Set the minimum marching epsilon for smooth shadow rays.

Parameters

eps	marching epsilon

References shaderProgram.

◆ SetSmoothShadowMarchingSteps()

void TerrainRaytracingWidget::SetSmoothShadowMarchingSteps ( int steps )

Set the maximum number of smooth shadow raymarching steps.

Parameters

steps max number of steps

References shaderProgram.

◆ SetSmoothShadowSteps()

void TerrainRaytracingWidget::SetSmoothShadowSteps ( int steps )

Set the number of smooth shadow steps.

Parameters

steps number of steps

References shaderProgram.

◆ SetSmoothShadowStrength()

void TerrainRaytracingWidget::SetSmoothShadowStrength ( float strength )

Set the smooth shadow strength.

Parameters

strength

References shaderProgram.

◆ SetSteps()

void TerrainRaytracingWidget::SetSteps ( int s )

Set the maximum number of raymarching step.

Parameters

s steps

References shaderProgram.

◆ ShowSides()

void TerrainRaytracingWidget::ShowSides ( bool showSides )

Chooses to show terrain sides.

Parameters

showSides true to show grey terrain sides, false for transparency.

References show_sides.

◆ ShowUnderside()

void TerrainRaytracingWidget::ShowUnderside ( bool showUnder )

Chooses to show terrain undersides.

Parameters

showUnder true to show underside of the terrain with the same texture, false for transparency.

References show_under.

◆ UpdateBuffer()

void TerrainRaytracingWidget::UpdateBuffer ( GLuint buffer )

Manually change the underlying heightfield buffer.

This function is useful when performing erosion on the gpu - no need to retrieve the data on the CPU and manually recreate all the buffers.

Note that the buffer must contain data whose size is equal to the base heightfield.

Parameters

buffer initialized buffer with elevation data.

References hfBuffer.

◆ UpdateInternal()

void TerrainRaytracingWidget::UpdateInternal ( )

virtual

Update the GPU data from the internal CPU heightfield pointer.

This function is computationally intensive as it recomputes the Lipschitz constant of the terrain and send data to the GPU.

References bbox, hfBuffer, K, ny, sf, shadingBuffer, tmpData, and zMax.

Referenced by SetHeightField().

◆ UseAlbedo()

void TerrainRaytracingWidget::UseAlbedo ( bool u = true )

Update the internal albedo texture flag.

Parameters

u	new value for albedo flag.

References useAlbedo.

◆ UseCost()

void TerrainRaytracingWidget::UseCost ( bool cost = true )

Set the cost shading flag.

Parameters

cost flag

References useCost.

◆ UseElevationShading()

void TerrainRaytracingWidget::UseElevationShading ( bool u )

Set the elevation shading flag.

Parameters

u flag

References useElevationShading, and useGreenBrownYellow.

◆ UseExternAlbedo()

void TerrainRaytracingWidget::UseExternAlbedo ( bool u = true )

Update the albedo texture flag.

Parameters

u	new value for albedo flag.

◆ UseGreenBrownYellowShading()

void TerrainRaytracingWidget::UseGreenBrownYellowShading ( bool u )

Set the shading from color map flag.

Parameters

u flag

References useElevationShading, and useGreenBrownYellow.

◆ UseSelfShadow()

void TerrainRaytracingWidget::UseSelfShadow ( bool use = true )

Set the smooth shadow flag.

Parameters

use flag

References shaderProgram.

◆ UseShading()

void TerrainRaytracingWidget::UseShading ( bool use = true )

Set the additional shading flag.

Parameters

use flag

References useShadingBuffer.

◆ UseSmoothShadow()

void TerrainRaytracingWidget::UseSmoothShadow ( bool use = true )

Set the smooth shadow flag.

Parameters

use flag

References shaderProgram.

◆ UseWireframe()

void TerrainRaytracingWidget::UseWireframe ( bool wire = true )

Set the wireframe flag.

Parameters

wire flag

References useWireframe.

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ SetAlbedo()

◆ SetAntialiasing()

◆ SetCamera()

◆ SetElevationRange()

◆ SetEpsilon()

◆ SetExternAlbedo()

◆ SetHeightField()

◆ SetLight()

◆ SetSelfShadowMarchingEpsilon()

◆ SetSelfShadowMarchingSteps()

◆ SetSelfShadowStrength()

◆ SetShading()

◆ SetSmoothShadowMarchingEpsilon()

◆ SetSmoothShadowMarchingSteps()

◆ SetSmoothShadowSteps()

◆ SetSmoothShadowStrength()

◆ SetSteps()

◆ ShowSides()

◆ ShowUnderside()

◆ UpdateBuffer()

◆ UpdateInternal()

◆ UseAlbedo()

◆ UseCost()

◆ UseElevationShading()

◆ UseExternAlbedo()

◆ UseGreenBrownYellowShading()

◆ UseSelfShadow()

◆ UseShading()

◆ UseSmoothShadow()

◆ UseWireframe()