de.grogra.imp3d.objects

Class Parallelogram

java.lang.Object

de.grogra.graph.impl.Edge

de.grogra.graph.impl.Node

de.grogra.imp3d.objects.Null

de.grogra.imp3d.objects.ShadedNull

de.grogra.imp3d.objects.AxisBase

de.grogra.imp3d.objects.Axis

de.grogra.imp3d.objects.Parallelogram

All Implemented Interfaces:

Transformation, Pickable, Raytraceable, Renderable, Manageable, PersistenceCapable, Shareable, Emitter, Light, Scattering, UserFields, XObject, Map, java.io.Serializable

public class Parallelogram
extends Axis
implements Pickable, Renderable, Light, Raytraceable

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class de.grogra.graph.impl.Node

Node.AccessorBridge, Node.FieldAttributeAccessor, Node.NType

Nested classes/interfaces inherited from interface de.grogra.util.Map

Map.Chain

Field Summary

Fields

Modifier and Type	Field and Description
static Node.NType	$TYPE
static Node.NType.Field	axis$FIELD
protected AreaLight	light
static Node.NType.Field	light$FIELD

Fields inherited from class de.grogra.imp3d.objects.Axis

endPosition, endPosition$FIELD, length, length$FIELD, startPosition, startPosition$FIELD

Fields inherited from class de.grogra.imp3d.objects.AxisBase

SCALE_V_MASK, scaleV$FIELD, USED_BITS

Fields inherited from class de.grogra.imp3d.objects.ShadedNull

INFINITE_MASK, interior, interior$FIELD, shader, shader$FIELD, treatedAsInfinite$FIELD

Fields inherited from class de.grogra.imp3d.objects.Null

transform, transform$FIELD, TRANSFORMING_MASK, transforming$FIELD

Fields inherited from class de.grogra.graph.impl.Node

ADDITIONAL_FIELDS, bits, DELETED, EXTENT_BIT, EXTENT_MASK, extentIndex$FIELD, extentTail$FIELD, HAS_OBSERVERS, IS_INTERPRETIVE, isInterpretive$FIELD, LAST_EXTENT_INDEX, layer$FIELD, MARK, mark$FIELD, MIME_TYPE, MIN_UNUSED_SPECIAL_OF_SOURCE, MIN_UNUSED_SPECIAL_OF_TARGET, name$FIELD

Fields inherited from interface de.grogra.ray.physics.Light

AMBIENT, AREA, DIRECTIONAL, NO_LIGHT, POINT, SKY

Fields inherited from interface de.grogra.ray.physics.Scattering

DELTA_FACTOR, IS_NON_OPAQUE, MIN_UNUSED_FLAG, NEEDS_NORMAL, NEEDS_POINT, NEEDS_TANGENTS, NEEDS_TRANSFORMATION, NEEDS_UV, RANDOM_RAYS_GENERATE_ORIGINS

Fields inherited from interface de.grogra.util.Map

DEFAULT_VALUE, EMPTY_MAP

Constructor Summary

Constructors

Constructor and Description
Parallelogram()
Parallelogram(float length, float width)

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(LightVisitor visitor)
double	completeRay(Environment env, Point3d vertex, Ray out)
float	computeBSDF(Environment env, Vector3f in, Spectrum specIn, Vector3f out, boolean photon, Spectrum bsdf) Evaluates bidirectional scattering distribution function for given input.
double	computeExitance(Environment env, Spectrum exitance) Evaluates the exitance function for given input.
RaytracerLeaf	createRaytracerLeaf(java.lang.Object object, boolean asNode, long pathId, GraphState gs)
void	draw(java.lang.Object object, boolean asNode, RenderState rs)
void	generateRandomOrigins(Environment env, RayList out, java.util.Random rnd) Pseudorandomly generates, for the given input, a set of origins for this emitter.
void	generateRandomRays(Environment env, Vector3f out, Spectrum specOut, RayList rays, boolean photon, java.util.Random rnd) Pseudorandomly generates, for the given input, a set of scattered rays.
float	getArea()
int	getAverageColor() Returns an average color for the scattering entity.
Vector3f	getAxis()
int	getFlags()
AreaLight	getLight()
int	getLightType() Determines the type of light source which is represented by this light.
protected Node.NType	getNTypeImpl() This method returns the Node.NType which describes the managed fields of the class of this node.
protected java.lang.Object	getObject(ObjectAttribute a, java.lang.Object placeIn, GraphState gs)
double	getSurfaceArea() Calculates the area of an object.
double	getTotalPower(Environment env) Computes the total power of this light source which is emitted to the region defined by env.bounds.
boolean	isIgnoredWhenHit() Determines whether the light source shall be ignored when a shot ray happens to hit the geometry of the light source.
boolean	isShadowless() Determines whether the light source casts shadows or not.
protected Node	newInstance() This method returns a new instance of the class of this node.
static void	pick(float height, Vector3f axis, Point3d origin, Vector3d direction, PickList list)
void	pick(java.lang.Object object, boolean asNode, Point3d origin, Vector3d direction, Matrix4d t, PickList list) Computes intersections of a given ray with this shape.
Light	resolveLight()
void	setAxis(float x, float y, float z)
void	setAxis(Vector3f value)
void	setLight(AreaLight value)

Methods inherited from class de.grogra.imp3d.objects.Axis

getEndPosition, getLength, getPivotShift, getStartPosition, postTransform, preTransform, setEndPoints, setEndPoints, setEndPoints, setEndPosition, setLength, setStartPosition

Methods inherited from class de.grogra.imp3d.objects.AxisBase

isScaleV, setScaleV

Methods inherited from class de.grogra.imp3d.objects.ShadedNull

getInterior, getShader, getSymbolColor, getVolume, isTreatedAsInfinite, setBackShader, setColor, setColor, setFrontShader, setInterior, setMaterial, setShader, setShaders, setTreatedAsInfinite

Methods inherited from class de.grogra.imp3d.objects.Null

getLocalTransformation, getTransform, getTranslation, isTransforming, setRotation, setScale, setTransform, setTransform, setTransform, setTransform, setTransform, setTransform, setTransform, setTransform, setTransforming, setTranslation

Methods inherited from class de.grogra.graph.impl.Node

addEdgeBitsTo, addReference, appendBranchNode, appendBranchNode, appendReferencesTo, clone, clone, cloneGraph, dump, dumpTree, dup, dupUnmanagedFields, edgeChanged, fieldModified, findAdjacent, findRefinementType, get, getAccessor, getAccessor, getAttributes, getAxisParent, getBoolean, getBranch, getBranchLength, getBranchNode, getBranchTail, getByte, getChar, getCommonAncestor, getCurrentGraphState, getDirectChildCount, getDouble, getEdgeAttributeAccessor, getEdgeAttributes, getEdgeBitsTo, getEdgeTo, getExtentIndex, getFirst, getFirstEdge, getFloat, getGraph, getId, getIndex, getInstantiator, getInt, getLayer, getLong, getManageableType, getName, getNeighbor, getNext, getNType, getOrCreateEdgeTo, getOrNull, getPersistenceManager, getPredecessor, getProvider, getShort, getSource, getStamp, getSuccessor, getSymbol, getTarget, getTransaction, getUserField, getUserFieldCount, getXClass, getXData, hasName, initProvider, initXClass, insertBranchNode, insertBranchNode, instantiateGraph, isAncestorOf, isDirection, isEncoarseOf, isManagingInstance, isMarked, isRoot, isSource, isTarget, manageableReadResolve, manageableWriteReplace, paramString, removeAll, removeEdgeBitsTo, removeFromChain, removeFromChain, removeReference, setBranch, setBranch, setExtentIndex, setGraphForDeserialization, setLayer, setMark, setName, setSuccessor, setSuccessor, specialEdgeAdded, specialEdgeRefModified, specialEdgeRemoved, toString, writeReplace

Methods inherited from class de.grogra.graph.impl.Edge

addEdgeBits, getBitMark, getEdgeBits, getObjectMark, getSpecialEdgeDescriptor, parseEdgeKeys, remove, removeEdgeBits, setBitMark, setEdgeBits, setObjectMark, testEdgeBits

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface de.grogra.persistence.PersistenceCapable

getBitMark, getObjectMark, setBitMark, setObjectMark

Field Detail

$TYPE

public static final Node.NType $TYPE

axis$FIELD

public static final Node.NType.Field axis$FIELD

light

protected AreaLight light

light$FIELD

public static final Node.NType.Field light$FIELD

Constructor Detail

Parallelogram

public Parallelogram()

Parallelogram

public Parallelogram(float length,
             float width)

Method Detail

accept

public void accept(LightVisitor visitor)

completeRay

public double completeRay(Environment env,
                 Point3d vertex,
                 Ray out)

Specified by:

completeRay in interface Emitter

computeBSDF

public float computeBSDF(Environment env,
                Vector3f in,
                Spectrum specIn,
                Vector3f out,
                boolean photon,
                Spectrum bsdf)

Description copied from interface: Scattering

Evaluates bidirectional scattering distribution function for given input.

The computed spectrum is an integral over the spectrum of the following product:

|cos θ| BSDF(ω_i, ν_i; ω_o, ν_o) where BSDF is the bidirectional scattering distribution function (= BRDF + BTDF) at the point env.point, ω_i the (negated) direction of the incoming light ray, ν_i the frequency where the incoming ray is sampled, ω_o the direction of the outgoing light ray, ν_o the frequency where the outgoing ray is sampled, and θ the angle between the surface normal and out.

If adjoint is false, in and out describe true light rays from light sources to sensors. In this case, ω_i = in, ω_o = out, and the integral is

bsdf(ν) = |cos θ| ∫ BSDF(in, ν_i; out, ν) specIn(ν_i) dν_i Otherwise, adjoint is true. in and out then describe importance rays (inverse light rays from sensors to light sources). In this case, ω_i = out, ω_o = in, and the integral is bsdf(ν) = |cos θ| ∫ BSDF(out, ν; in, ν_o) specIn(ν_o) dν_o

If this Scattering instance is in fact a Light source, adjoint is false, and the BSDF is defined as BSDF(in, μ; ω, ν) = L¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted radiance at env.point, see Emitter. In this case, in is not used.

If this Scattering instance is in fact a Sensor, adjoint is true, and the BSDF is defined as BSDF(ω, ν; in, μ) = W¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted importance at env.point, see Emitter. In this case, in is not used.

The computation should be physically valid. This excludes, e.g., ambient or emissive light contributions.

The returned value is the value of the probability density p_ω that would be calculated by Scattering.generateRandomRays(de.grogra.ray.physics.Environment, javax.vecmath.Vector3f, de.grogra.ray.physics.Spectrum, de.grogra.ray.util.RayList, boolean, java.util.Random) if the ray happened to be one of the randomly generated rays.

Specified by:

computeBSDF in interface Scattering

Parameters:

env - the environment for scattering

in - the (negated) direction unit vector of the incoming ray (i.e., pointing away from the surface)

specIn - the spectrum of the incoming ray

out - the direction unit vector of the outgoing ray (i.e., pointing away from the surface)

photon - light ray or importance ray?

bsdf - the computed spectrum of the outgoing ray will be placed in here

Returns:

the value of the probability density for the ray direction

computeExitance

public double computeExitance(Environment env,
                     Spectrum exitance)

Description copied from interface: Emitter

Evaluates the exitance function for given input. The computed value is the spectrum of the radiant exitance (emitted power per area) L⁰_j(x, ν) at the point env.point in case of light sources, or the corresponding function W⁰_j(x, ν) in case of sensors.

The returned value is the value of the probability density p_x that would be calculated by Emitter.generateRandomOrigins(de.grogra.ray.physics.Environment, de.grogra.ray.util.RayList, java.util.Random) if env.point happened to be one of the randomly generated origins.

Specified by:

computeExitance in interface Emitter

Parameters:

env - the environment for scattering

exitance - the exitance values will be placed in here

Returns:

the value of the probability density for the ray origin

createRaytracerLeaf

public RaytracerLeaf createRaytracerLeaf(java.lang.Object object,
                                boolean asNode,
                                long pathId,
                                GraphState gs)

Specified by:

createRaytracerLeaf in interface Raytraceable

draw

public void draw(java.lang.Object object,
        boolean asNode,
        RenderState rs)

Specified by:

draw in interface Renderable

generateRandomOrigins

public void generateRandomOrigins(Environment env,
                         RayList out,
                         java.util.Random rnd)

Description copied from interface: Emitter

Pseudorandomly generates, for the given input, a set of origins for this emitter. They are generated such that they can be used for Monte Carlo-based photon tracing algorithms in the following way.

At first, we consider the case where the emitter is in fact a light source. Let L(x, ω, ν) be the emitted spectral radiance for the frequency ν at the light's surface point x in direction ω. The radiant exitance (emitted spectral power per area) at x is defined as

L⁰(x, ν) = ∫ cos θ L(x, ω, ν) dω where θ is the angle between the surface normal and ω. Now the directional distribution of the emitted radiance at x can be described by the density L¹(x, ω, ν) = L(x, ω, ν) / L⁰(x, ν) so that the radiance is split into L(x, ω, ν) = L⁰(x, ν) L¹(x, ω, ν) Let o_i and s_i denote the origins and spectra of the N generated rays (N = rays.size). Then for a function f(x, ν) which is to be integrated over the light surface, the sum 1 / N ∑_i s_i(ν) f(o_i, ν) is an unbiased estimate for the integral ∫ L⁰(x, ν) f(x, ν) dA The integral ranges over the whole surface A of the light source. As a consequence, the spectrum of a ray is to be considered as the ray's radiant spectral power.

Now if the emitter is a sensor, let W(x, ω, ν) be the emitted spectral importance for frequency ν at the sensors's surface point x in direction ω. The quantities W⁰(x, ν) and W¹(x, ω, ν) are defined similarly to the case of light sources:

W⁰(x, ν) = ∫ cos θ W(x, ω, ν) dω
W(x, ω, ν) = W⁰(x) W¹(x, ω, ν) The formulas for light sources are valid for sensors if the L-quantites are replaced by the corresponding W-quantities.

Let p_x be the probability density used for the ray origin, then the field originDensity is set to p_x(o_i) for each ray. For emitters which are concentrated at a single point (e.g., point lights) p_x is not a regular function, the value originDensity will be set to a multiple of Scattering.DELTA_FACTOR.

The ray properties which are not mentioned in the given formulas are neither used nor modified. These are the direction and its density.

Specified by:

generateRandomOrigins in interface Emitter

Parameters:

env - the environment

out - the outgoing rays to be generated

rnd - pseudorandom generator

generateRandomRays

public void generateRandomRays(Environment env,
                      Vector3f out,
                      Spectrum specOut,
                      RayList rays,
                      boolean photon,
                      java.util.Random rnd)

Description copied from interface: Scattering

Pseudorandomly generates, for the given input, a set of scattered rays. The scattered rays are generated such that they can be used for a Monte Carlo integration of a function f(ω;ν) over cos θ BSDF(ω_i, ν_i; ω_o, ν_o) in the following way:

• If adjoint is false, out = ω_o describes the direction of an outgoing light ray. In this case, the integration is with respect to ω_i. Let g(ω, ν; out, μ) = BSDF(ω, ν; out, μ)
• Otherwise, adjoint is true. In this case, out = ω_i describes the direction of an outgoing importance ray (an inverse light ray). Now the integration is with respect to ω_o. Let g(ω, ν; out, μ) = BSDF(out, μ; ω, ν)

Let d_i and s_i denote the directions and spectra of the N generated rays (N = rays.size). Then, for every frequency ν the sum 1 / N ∑_i s_i(ν) f(d_i; ν) is an unbiased estimate for the integral ∫ cos θ f(ω; ν) g(ω, ν; out, μ) specOut(μ) dμ dω θ is the angle between the surface normal and ω. The domain of integration is the whole sphere, since the bidirectional scattering distribution includes both reflection and transmission (BSDF = BRDF + BTDF).

If this Scattering instance is in fact a Light source, adjoint is true, and the BSDF is defined as BSDF(out, μ; ω, ν) = L¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted radiance at env.point, see Emitter. In this case, out is not used.

If this Scattering instance is in fact a Sensor, adjoint is false, and the BSDF is defined as BSDF(ω, ν; out, μ) = W¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted importance at env.point, see Emitter. In this case, out is not used.

Let p_ω be the probability density used for the ray direction (measured with respect to solid angle ω), then the field directionDensity of the ray i is set to p_ω(d_i). For ideal specular reflection or transmission, or for directional lights or sensors, p_ω is not a regular function, the value directionDensity will be set to a multiple of Scattering.DELTA_FACTOR.

The ray properties which are not mentioned in the given formulas are neither used nor modified. These are the origin and its density.

Specified by:

generateRandomRays in interface Scattering

Parameters:

env - the environment for scattering

out - the direction unit vector of the outgoing ray (i.e., pointing away from the surface)

specOut - the spectrum of the outgoing ray

rays - the rays to be generated

photon - represents out a light ray or an importance ray?

rnd - pseudorandom generator

See Also:

Scattering.computeBSDF(de.grogra.ray.physics.Environment, javax.vecmath.Vector3f, de.grogra.ray.physics.Spectrum, javax.vecmath.Vector3f, boolean, de.grogra.ray.physics.Spectrum)

getArea

public float getArea()

getAverageColor

public int getAverageColor()

Description copied from interface: Scattering

Returns an average color for the scattering entity. This color is used for simplified graphical representations of the corresponding objects.

Specified by:

getAverageColor in interface Scattering

Returns:

an average color in Java's default sRGB color space, encoded as an int (0xAARRGGBB).

getAxis

public Vector3f getAxis()

getFlags

public int getFlags()

Specified by:

getFlags in interface Scattering

getLight

public AreaLight getLight()

getLightType

public int getLightType()

Description copied from interface: Light

Determines the type of light source which is represented by this light.

Specified by:

getLightType in interface Light

Returns:

one of Light.NO_LIGHT, Light.POINT, Light.AREA, Light.DIRECTIONAL, Light.SKY, Light.AMBIENT.

getNTypeImpl

protected Node.NType getNTypeImpl()

Description copied from class: Node

This method returns the Node.NType which describes the managed fields of the class of this node. This method has to be implemented in every concrete subclass.

Overrides:

getNTypeImpl in class ShadedNull

Returns:

type describing the managed fields of the class of this node

getObject

protected java.lang.Object getObject(ObjectAttribute a,
                         java.lang.Object placeIn,
                         GraphState gs)

Overrides:

getObject in class Node

getSurfaceArea

public double getSurfaceArea()

Calculates the area of an object. (Note: both sides are counted!) Intersection with other object are not considered.The total area will be calculated. A=a*b*2

Overrides:

getSurfaceArea in class ShadedNull

Returns:

area

getTotalPower

public double getTotalPower(Environment env)

Description copied from interface: Light

Computes the total power of this light source which is emitted to the region defined by env.bounds. Note that the computed value is not necessarily exact: It should be used just as a hint, e.g., when one of a set of lights has to be chosen randomly on the basis of their relative power.

Specified by:

getTotalPower in interface Light

Parameters:

env - environment which defines the bounds of the scene

Returns:

total power emitted to the region env.bounds

isIgnoredWhenHit

public boolean isIgnoredWhenHit()

Description copied from interface: Light

Determines whether the light source shall be ignored when a shot ray happens to hit the geometry of the light source.

Specified by:

isIgnoredWhenHit in interface Light

Returns:

true iff the light source shall be ignored

isShadowless

public boolean isShadowless()

Description copied from interface: Light

Determines whether the light source casts shadows or not.

Specified by:

isShadowless in interface Light

Returns:

true iff the light source does not cast shadows

newInstance

protected Node newInstance()

Description copied from class: Node

This method returns a new instance of the class of this node. This method has to be implemented in every concrete subclass.

Overrides:

newInstance in class ShadedNull

Returns:

new instance of class of this node

pick

public static void pick(float height,
        Vector3f axis,
        Point3d origin,
        Vector3d direction,
        PickList list)

pick

public void pick(java.lang.Object object,
        boolean asNode,
        Point3d origin,
        Vector3d direction,
        Matrix4d t,
        PickList list)

Description copied from interface: Pickable

Computes intersections of a given ray with this shape.

Specified by:

pick in interface Pickable

Parameters:

object - the object of which this shape is an attribute

asNode - true iff object is a node

origin - the origin of the ray, in local coordinates

direction - the direction of the ray, in local coordinates

t - the transformation from local coordinates to world coordinates

list - the list to which intersections have to be added

resolveLight

public Light resolveLight()

setAxis

public void setAxis(float x,
           float y,
           float z)

setAxis

public void setAxis(Vector3f value)

setLight

public void setLight(AreaLight value)