A ActorEventCallback used to render a volume using viewport aligned slices. More...

#include <SlicedVolume.hpp>

Inheritance diagram for vl::SlicedVolume:

Public Member Functions
	SlicedVolume ()
	Constructor.
void	onActorRenderStarted (Actor actor, real frame_clock, const Camera cam, Renderable renderable, const Shader shader, int pass)
	Event generated just before an Actor is rendered but after the render states are ready and setup.
void	onActorDelete (Actor *)
	Event notifying that an Actor is being deleted.
void	bindActor (Actor *)
	Binds a SlicedVolume to an Actor so that the SlicedVolume can generate the viewport aligned slices' geometry for the Actor as appropriate.
virtual void	updateUniforms (Actor actor, real clock, const Camera camera, Renderable rend, const Shader shader)
	Updates the uniforms used by the GLSLProgram to render the volume each time the onActorRenderStarted() method is called.
void	setSliceCount (int count)
	Defines the number of slices used to render the volume: more slices generate a better (and slower) rendering.
int	sliceCount () const
	Returns the number of slices used to render the volume.
Geometry *	geometry ()
	Returns the Geometry associated to a SlicedVolume and its bound Actor.
const Geometry *	geometry () const
	Returns the Geometry associated to a SlicedVolume and its bound Actor.
void	setBox (const AABB &box)
	Defines the dimensions of the box enclosing the volume.
const AABB &	box () const
	The dimensions of the box enclosing the volume.
const fvec3 *	texCoords () const
	Returns the texture coordinates assigned to each of the 8 box corners of the volume.
fvec3 *	texCoords ()
	Returns the texture coordinates assigned to each of the 8 box corners of the volume.
void	generateTextureCoordinates (const ivec3 &size)
	Generates a default set of texture coordinates for the 8 box corners of the volume based on the given texture dimensions.
void	generateTextureCoordinates (const ivec3 &img_size, const ivec3 &min_corner, const ivec3 &max_corner)
	Generates a default set of texture coordinates for the 8 box corners of the volume based on the given texture dimensions.
Protected Attributes
int	mSliceCount
ref< Geometry >	mGeometry
AABB	mBox
fmat4	mCache
fvec3	mTexCoord [8]

Detailed Description

A ActorEventCallback used to render a volume using viewport aligned slices.

Pictures from: Sliced Volume Rendering with Transfer Functions and Lighting Tutorial tutorial.

Using the SlicedVolume class is very simple, see Sliced Volume Rendering with Transfer Functions and Lighting Tutorial for a complete example.

Basically all SlicedVolume does is to compute the correct texture coordinates and generates on the fly N viewport aligned slices, where N can be specified by the user with setSliceCount(). Such slices then can be rendered using a GLSLProgram specified by the user, thus you can achieve virtually any kind of visual effect with it.

The user can reimplement the updateUniforms() method to update his own uniform variables before the volume is rendered. By default updateUniforms() updates the position of up to 4 lights in object space. Such positions are stored in the "uniform vec3 light_position[4]" variable. The updateUniforms() method also fills the "uniform bool light_enable[4]" variable with a flag marking if the Nth light is active or not. These light values are computed based on the lights bound to the current Shader. The updateUniforms() method also fills the "uniform vec3 eye_position" variable which contains the camera position in object space, useful to compute specular highlights etc.

See also:

Definition at line 42 of file SlicedVolume.hpp.

Constructor & Destructor Documentation

SlicedVolume::SlicedVolume ( )

Constructor.

Definition at line 79 of file SlicedVolume.cpp.

References mGeometry, mSliceCount, mTexCoord, and VL_DEBUG_SET_OBJECT_NAME.

Member Function Documentation

void SlicedVolume::onActorRenderStarted	(	Actor *	actor,
		real	frame_clock,
		const Camera *	cam,
		Renderable *	renderable,
		const Shader *	shader,
		int	pass
	)		`[virtual]`

Event generated just before an Actor is rendered but after the render states are ready and setup.

Reimplement to react to this event.

Parameters:

actor	The Actor bound to this rendering callback.
frame_clock	The current rendering frame time, usually used for animation purposes.
cam	The camera used for the current rendering.
renderable	The currently selected Actor LOD.
shader	The currently active Shader.
pass	The current Actor[s] rendering pass.

Implements vl::ActorEventCallback.

Definition at line 168 of file SlicedVolume.cpp.

References box(), vl::dot(), vl::ref< T >::get(), vl::Shader::getGLSLProgram(), vl::Matrix4< T_Scalar >::getInverse(), mCache, mGeometry, vl::PT_TRIANGLES, sliceCount(), texCoords(), vl::Actor::transform(), updateUniforms(), vl::Camera::viewMatrix(), VL_CHECK, vl::Transform::worldMatrix(), and vl::Vector3< T_Scalar >::z().

void vl::SlicedVolume::onActorDelete ( Actor * actor ) [inline, virtual]

Event notifying that an Actor is being deleted.

Implements vl::ActorEventCallback.

Definition at line 52 of file SlicedVolume.hpp.

void SlicedVolume::bindActor ( Actor * actor )

Binds a SlicedVolume to an Actor so that the SlicedVolume can generate the viewport aligned slices' geometry for the Actor as appropriate.

Definition at line 162 of file SlicedVolume.cpp.

References vl::Actor::actorEventCallbacks(), vl::ref< T >::get(), mGeometry, vl::Collection< T >::push_back(), and vl::Actor::setLod().

void SlicedVolume::updateUniforms	(	Actor *	actor,
		real	clock,
		const Camera *	camera,
		Renderable *	rend,
		const Shader *	shader
	)		`[virtual]`

Updates the uniforms used by the GLSLProgram to render the volume each time the onActorRenderStarted() method is called.

Reimplement this method to update the uniform variables of your GLSL program before the volume is rendered.

By default updateUniforms() updates the position of up to 4 lights in object space. Such positions are stored in the "uniform vec3 light_position[4]" variable. The updateUniforms() method also fills the "uniform bool light_enable[4]" variable with a flag marking if the Nth light is active or not. These light values are computed based on the lights bound to the current Shader. The updateUniforms() method also fills the "uniform vec3 eye_position" variable which contains the camera position in object space, useful to compute specular highlights etc.

Definition at line 102 of file SlicedVolume.cpp.

References vl::Light::boundTransform(), vl::Shader::getGLSLProgram(), vl::Matrix4< T_Scalar >::getInverse(), vl::Shader::getLight(), vl::Matrix4< T_Scalar >::getT(), vl::GLSLProgram::getUniformLocation(), vl::Actor::gocUniform(), vl::Camera::modelingMatrix(), NULL, vl::Light::position(), vl::Uniform::setUniform(), vl::Uniform::setUniform1i(), vl::Actor::transform(), vl::Transform::worldMatrix(), and vl::Vector4< T_Scalar >::xyz().