org.sunflow.core.light
Class PointLight

java.lang.Object
  org.sunflow.core.light.PointLight

All Implemented Interfaces:

LightSource, RenderObject

public class PointLight
extends java.lang.Object
implements LightSource

Constructor Summary

PointLight()

Method Summary

Instance	createInstance() Create an instance which represents the geometry of this light source.
int	getNumSamples() Get the maximum number of samples that can be taken from this light source.
void	getPhoton(double randX1, double randY1, double randX2, double randY2, Point3 p, Vector3 dir, Color power) Gets a photon to emit from this light source by setting each of the arguments.
float	getPower() Get the total power emitted by this light source.
void	getSamples(ShadingState state) Samples the light source to compute direct illumination.
boolean	update(ParameterList pl, SunflowAPI api) Update this object given a list of parameters.

Methods inherited from class java.lang.Object

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

Constructor Detail

PointLight

public PointLight()

Method Detail

update

public boolean update(ParameterList pl,
                      SunflowAPI api)

Description copied from interface: RenderObject

Update this object given a list of parameters. This method is guarenteed to be called at least once on every object, but it should correctly handle empty parameter lists. This means that the object should be in a valid state from the time it is constructed. This method should also return true or false depending on whether the update was succesfull or not.

Specified by:

update in interface RenderObject

Parameters:

pl - list of parameters to read from

api - reference to the current scene

Returns:

true if the update is succesfull, false otherwise

getNumSamples

public int getNumSamples()

Description copied from interface: LightSource

Get the maximum number of samples that can be taken from this light source. This is currently only used for statistics reporting.

Specified by:

getNumSamples in interface LightSource

Returns:

maximum number of samples to be taken from this light source

getSamples

public void getSamples(ShadingState state)

Description copied from interface: LightSource

Samples the light source to compute direct illumination. Light samples can be created using the LightSample class and added to the current ShadingState. This method is responsible for the shooting of shadow rays which allows for non-physical lights that don't cast shadows. It is recommended that only a single shadow ray be shot if ShadingState.getDiffuseDepth() is greater than 0. This avoids an exponential number of shadow rays from being traced.

Specified by:

getSamples in interface LightSource

Parameters:

state - current state, including point to be shaded

See Also:

LightSample

getPhoton

public void getPhoton(double randX1,
                      double randY1,
                      double randX2,
                      double randY2,
                      Point3 p,
                      Vector3 dir,
                      Color power)

Description copied from interface: LightSource

Gets a photon to emit from this light source by setting each of the arguments. The two sampling parameters are points on the unit square that can be used to sample a position and/or direction for the emitted photon.

Specified by:

getPhoton in interface LightSource

Parameters:

randX1 - sampling parameter

randY1 - sampling parameter

randX2 - sampling parameter

randY2 - sampling parameter

p - position to shoot the photon from

dir - direction to shoot the photon in

power - power of the photon

getPower

public float getPower()

Description copied from interface: LightSource

Get the total power emitted by this light source. Lights that have 0 power will not emit any photons.

Specified by:

getPower in interface LightSource

Returns:

light source power

createInstance

public Instance createInstance()

Description copied from interface: LightSource

Create an instance which represents the geometry of this light source. This instance will be created just before and removed immediately after rendering. Non-area light sources can return null to indicate that no geometry needs to be created.

Specified by:

createInstance in interface LightSource

Returns:

an instance describing the light source