TBasicDistantLight Class Reference
[Base Classes for plugins]

Inheritance diagram for TBasicDistantLight:


Public Member Functions
	TBasicDistantLight ()
virtual MCCOMErr MCCOMAPI	ExtensionDataChanged ()
virtual MCCOMErr MCCOMAPI	SetTransform (TTransform3D *transform)
virtual MCCOMErr MCCOMAPI	GetDirection (const TVector3 &point, TVector3 &resultDirection, real &resultDistance)
virtual boolean MCCOMAPI	GetColor (const TVector3 &point, const TVector3 &direction, const real distance, TMCColorRGB &result, real &ShadowIntensity)
virtual boolean MCCOMAPI	IsVisibleInPerspective ()
virtual uint32 MCCOMAPI	GetPrimitiveID ()
virtual MCCOMErr MCCOMAPI	ForEachShadowBuffer (ForEachShadowBufferCallback proc, void *priv)
virtual boolean MCCOMAPI	GetUVfromDirection (TVector2 &uv, const TVector3 &direction) const
virtual MCCOMErr MCCOMAPI	GetStandardLight (TStandardLight &light) const
virtual void MCCOMAPI	InitSampling (const TBBox3D &sceneBoundingBox, real &solidAngle, int32 &regionCount)
virtual void MCCOMAPI	GetRandomRay (int32 regionIndex, Ray3D &ray) const
virtual int32 MCCOMAPI	GetShadowBufferCount () const
virtual void MCCOMAPI	GetShadowBuffer (int32 bufferIndex, I3DShCamera **camera, TBBox2D &uvBox) const
Public Attributes
Data	fData
Static Public Attributes
static const MCGUID	ClassId
Protected Attributes
TMCColorRGB	fBritColor
TTransform3D	fTransform
TVector3	fI
TVector3	fJ
TVector3	fD
TVector2	fMin
TVector2	fMax
TMCArray< int32 >	fSampleIndices
Classes
struct	Data

Detailed Description

Basic Distant Light class. Derive from this for a default implementation of an I3DExLightsource for a distant type light

See also:: I3DExLightsource

Constructor & Destructor Documentation

TBasicDistantLight::TBasicDistantLight ( )

Member Function Documentation

virtual MCCOMErr MCCOMAPI TBasicDistantLight::ExtensionDataChanged ( ) [virtual]

Called each time a parameter of the parameter map (Pmap) is modified. This should only be used to invalidate caches and should be quick since it can be called many times.
Reimplemented from TBasicDataExchanger.

virtual MCCOMErr MCCOMAPI TBasicDistantLight::ForEachShadowBuffer ( ForEachShadowBufferCallback proc,

void * priv

) [virtual]

Deprecated:

Reimplemented from TBasicLight.

virtual boolean MCCOMAPI TBasicDistantLight::GetColor ( const TVector3 & point,

const TVector3 & direction,

const real distance,

TMCColorRGB & result,

real & ShadowIntensity

) [virtual]

Returns the color of light seen through a given point.
When using a spot, use the position parameter and the light source position and orientation to determine whether a point is in the light beam or not. When using a sun, use the direction parameter to calculate the intensity. When lighting is based on distance, (such as distance fall-off), use the distance parameter.

Parameters:

point The point on the surface for which the lighting is going to be calculated.

direction The direction from which the light arrives on the point (as calculated in GetDirection()).

distance The distance from the point to the light (as calculated in GetDirection()).

result The color of the light that reaches this point

ShadowIntensity The intensity of the shadow cast by that light

Reimplemented from TBasicLight.

virtual MCCOMErr MCCOMAPI TBasicDistantLight::GetDirection ( const TVector3 & point,

TVector3 & resultDirection,

real & resultDistance

) [virtual]

Returns the direction from the point to the light source as well as the distance between the surface point and light source. GetDirection() is called prior to GetColor() to perform preliminary calculations. The surface point is the point on the object where the light is about to be calculated.
A light bulb typically calculates resultDirection by subtracting the postion point to the light source origin, then normalizes the results. A simulated sun light returns its light direction in resultDirection, and the maximum possible value in resultDistance.

Parameters:

point The point on the surface for which the lighting is going to be calculated

resultDirection The direction from which the light arrives on the point

resultDistance The distance from the point to the light

Reimplemented from TBasicLight.

virtual uint32 MCCOMAPI TBasicDistantLight::GetPrimitiveID ( ) [virtual]

Returns the ID of the primitive that is display in place of the light.
Reimplemented from TBasicLight.

virtual void MCCOMAPI TBasicDistantLight::GetRandomRay ( int32 regionIndex,

Ray3D & ray

) const [virtual]

Returns a random ray starting from the light The rays should sample uniformly a solid angle that contains at least the intersection of the light cone (or sphere) and the scene.

Note:
Must be called after InitSampling

Parameters:

ray A reference to the ray that should be returned

regionIndex Index of the region in which the ray should be picked

Reimplemented from TBasicLight.

virtual void MCCOMAPI TBasicDistantLight::GetShadowBuffer ( int32 bufferIndex,

I3DShCamera ** camera,

TBBox2D & uvBox

) const [virtual]

Returns a camera equivalent to a shadow buffer

Parameters:

bufferIndex index of the shadow buffer (0 based)

camera returns a pointer to the camera corresponding to the shadow buffer

uvBox returns the box in screen coordinates corresponding to the shadow buffer

Reimplemented from TBasicLight.

virtual int32 MCCOMAPI TBasicDistantLight::GetShadowBufferCount ( ) const [virtual]

Returns the number of shadow buffer needed for this light
Reimplemented from TBasicLight.

virtual MCCOMErr MCCOMAPI TBasicDistantLight::GetStandardLight ( TStandardLight & light ) const [virtual]

Retrieves a standard description of the light for use in the interactive renderer.

Parameters:

light A reference to the simplified description of the light for the interactive rendering

Reimplemented from TBasicLight.

virtual boolean MCCOMAPI TBasicDistantLight::GetUVfromDirection ( TVector2 & uv,

const TVector3 & direction

) const [virtual]

returns the uv for the gel given a direction

Parameters:

uv The uv that are returned.

direction The direction as calculated in GetDirection()

Reimplemented from TBasicLight.

virtual void MCCOMAPI TBasicDistantLight::InitSampling ( const TBBox3D & sceneBoundingBox,

real & solidAngle,

int32 & regionCount

) [virtual]

Initialize sampling of the light and returns the solid angle containing the sampling rays. It must be called before GetRandomRay

Parameters:

sceneBoundingBox The bounding box of the scene

solidAngle Returns the solid Angle of the sampling rays

regionCount Returns the number of region for ray sampling (each region represent an equal number of rays)

Reimplemented from TBasicLight.

virtual boolean MCCOMAPI TBasicDistantLight::IsVisibleInPerspective ( ) [virtual]

Returns true if the light should be displayed in the 3D View. In this case, the lights is displayed with the geometry of the primitive given by GetPrimitiveID().
If it returns false, then the light is not displayed, this is used for sun lights for example.
Reimplemented from TBasicLight.

virtual MCCOMErr MCCOMAPI TBasicDistantLight::SetTransform ( TTransform3D * transform ) [virtual]

Called to tell a light source its position and orientation in space. This function is used to cache transform information to speed up GetDirection() and GetColor().

Parameters:

transform A pointer to the Global Transform of the light

Reimplemented from TBasicLight.