TerrainRaytracingWidget Class Reference

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

#include <realtime.h>

Public Member Functions
	TerrainRaytracingWidget (QWidget *parent=nullptr)
	Default constructor.
	~TerrainRaytracingWidget ()
	Destructor. Release shader program, vao and textures.
virtual void	SetHeightField (ScalarField2 *hfPtr)
	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 (const bool &=true)
	Set the additional shading flag.
void	SetExternAlbedo (GLuint)
	Update the albedo texture with an existing OpenGL texture. UseAlbedo(true) should have been called before, or no update will be performed.
void	UseExternAlbedo (const 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 (const bool &=true)
	Update the internal albedo texture flag.
void	UseWireframe (const bool &=true)
	Set the wireframe flag.
void	UseCost (const bool &=true)
	Set the cost shading flag.
void	UseElevationShading (const bool &)
	Set the elevation shading flag.
void	UseGreenBrownYellowShading (const 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	UseSmoothShadow (const 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 (const 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.

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

albedo

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.

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

(

const bool &

u = true

)

Update the internal albedo texture flag.

Parameters

u	new value for albedo flag.

References useAlbedo.

UseCost()

void TerrainRaytracingWidget::UseCost

(

const bool &

cost = true

)

Set the cost shading flag.

Parameters

cost

flag

References useCost.

UseElevationShading()

void TerrainRaytracingWidget::UseElevationShading

(

const bool &

u

)

Set the elevation shading flag.

Parameters

u

flag

References useElevationShading, and useGreenBrownYellow.

UseExternAlbedo()

void TerrainRaytracingWidget::UseExternAlbedo

(

const bool &

u = true

)

Update the albedo texture flag.

Parameters

u	new value for albedo flag.

UseGreenBrownYellowShading()

void TerrainRaytracingWidget::UseGreenBrownYellowShading

(

const bool &

u

)

Set the shading from color map flag.

Parameters

u

flag

References useElevationShading, and useGreenBrownYellow.

UseSelfShadow()

void TerrainRaytracingWidget::UseSelfShadow

(

const bool &

use = true

)

Set the smooth shadow flag.

Parameters

use

flag

References shaderProgram.

UseShading()

void TerrainRaytracingWidget::UseShading

(

const bool &

use = true

)

Set the additional shading flag.

Parameters

use

flag

References useShadingBuffer.

UseSmoothShadow()

void TerrainRaytracingWidget::UseSmoothShadow

(

const bool &

use = true

)

Set the smooth shadow flag.

Parameters

use

flag

References shaderProgram.

UseWireframe()

void TerrainRaytracingWidget::UseWireframe

(

const bool &

wire = true

)

Set the wireframe flag.

Parameters

wire

flag

References useWireframe.