Module raytracer

Package de.grogra.ray.physics

Interface Light

All Superinterfaces:

Emitter, Scattering

All Known Subinterfaces:

Light

All Known Implementing Classes:

AmbientLight, DirectionalLight, LaserLight, LightBase, Parallelogram, PhysicalLight, PointLight, Sky, SpectralLight, SpotLight, SunSkyLight, SunSkyToDirectionalLightWrapper

public interface Light
extends Emitter

A Light instance represents a light source. The interface specializes the common methods of the Emitter interface for light sources.

Author:

Ole Kniemeyer

Field Summary

Fields

Modifier and Type	Field	Description
static final int	AMBIENT	This return value for getLightType() indicates an ambient light.
static final int	AREA	This return value for getLightType() indicates an area light.
static final int	DIRECTIONAL	This return value for getLightType() indicates a directional light.
static final int	NO_LIGHT	This return value for getLightType() indicates that this light should actually be ignored.
static final int	POINT	This return value for getLightType() indicates a point light, i.e., a light source whose rays emanate from a single point.
static final int	SKY	This return value for getLightType() indicates a sky light.

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

Method Summary

Modifier and Type	Method	Description
int	getLightType()	Determines the type of light source which is represented by this light.
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.

Methods inherited from interface de.grogra.ray.physics.Emitter

completeRay, computeExitance, generateRandomOrigins

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

computeBSDF, generateRandomRays, getAverageColor, getFlags

Field Details

NO_LIGHT

static final int NO_LIGHT

This return value for getLightType() indicates that this light should actually be ignored.

See Also:

• Constant Field Values

POINT

static final int POINT

This return value for getLightType() indicates a point light, i.e., a light source whose rays emanate from a single point. This includes the usual point lights which radiate equally in all directions, but also more general lights with a direction-dependent radiant intensity, e.g., spot lights.

See Also:

• Constant Field Values

AREA

static final int AREA

This return value for getLightType() indicates an area light.

See Also:

• Constant Field Values

DIRECTIONAL

static final int DIRECTIONAL

This return value for getLightType() indicates a directional light.

See Also:

• Constant Field Values

SKY

static final int SKY

This return value for getLightType() indicates a sky light.

See Also:

• Constant Field Values

AMBIENT

static final int AMBIENT

This return value for getLightType() indicates an ambient light. Ambient lights have no physically plausible counterpart in the real world and, thus, should not be considered in physically based rendering at all.

See Also:

• Constant Field Values

Method Details

getLightType

int getLightType()

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

Returns:

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

isShadowless

boolean isShadowless()

Determines whether the light source casts shadows or not.

Returns:

true iff the light source does not cast shadows

isIgnoredWhenHit

boolean isIgnoredWhenHit()

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

Returns:

true iff the light source shall be ignored

getTotalPower

double getTotalPower(Environment env)

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.

Parameters:

env - environment which defines the bounds of the scene

Returns:

total power emitted to the region env.bounds