I3DShLightsource Struct Reference
[Shell Interfaces]

Inheritance diagram for I3DShLightsource:


Public Member Functions
virtual MCCOMErr MCCOMAPI	GetLightGlobalTransform (TTransform3D *transform)=0
virtual MCCOMErr MCCOMAPI	ForEachShadowBuffer (ForEachShadowBufferCallback proc, void *priv)=0
virtual MCCOMErr MCCOMAPI	GetLightParameter (int32 keyword, void *parameter)=0
virtual MCCOMErr MCCOMAPI	GetPrimitiveID (int32 &primID)=0
virtual MCCOMErr MCCOMAPI	GetNewTrace (int16 &nb, TLightTraceElement *&traceElem)=0
virtual I3DExLightsource *MCCOMAPI	GetValidExLightNoAddRef ()=0
virtual boolean MCCOMAPI	GetDirection (const TVector3 &position, TVector3 &resultDirection, real &resultDistance)=0
virtual boolean MCCOMAPI	GetColor (const TVector3 &position, const TVector3 &direction, const real distance, TMCColorRGB &result, real &shadowIntensity)=0
virtual MCCOMErr MCCOMAPI	SetGelComponentByID (int32 kindID)=0
virtual MCCOMErr MCCOMAPI	SetGelComponent (I3DShLightsourceGel *gel, ECloneMode cloneMode)=0
virtual void MCCOMAPI	GetGelComponent (I3DShLightsourceGel **gel)=0
virtual MCCOMErr MCCOMAPI	SetShadowFeatureByID (int32 kindID)=0
virtual MCCOMErr MCCOMAPI	SetShadowFeature (I3DShShadowFeature *feature, ECloneMode cloneMode)=0
virtual void MCCOMAPI	GetShShadowFeature (I3DShShadowFeature **feature)=0
virtual void MCCOMAPI	GetExShadowFeature (I3DExShadowFeature **feature)=0
virtual MCCOMErr MCCOMAPI	SetLightComponentByID (int32 kindID)=0
virtual MCCOMErr MCCOMAPI	SetLightComponent (IShComponent *component, ECloneMode cloneMode)=0
virtual MCCOMErr MCCOMAPI	GetLightComponent (IShComponent **component)=0
virtual MCCOMErr MCCOMAPI	GetLightInfo (boolean &hasLightCone, boolean &hasLightSphere, real &halfAngle, TTransform3D &transform)=0
virtual MCCOMErr MCCOMAPI	GetStandardLight (TStandardLight &light) const =0
virtual void MCCOMAPI	InitSampling (const TBBox3D &sceneBoundingBox, real &solidAngle, int32 &regionCount)=0
virtual void MCCOMAPI	GetRandomRay (int32 regionIndex, Ray3D &ray)=0
virtual int32 MCCOMAPI	GetShadowBufferCount ()=0
virtual void MCCOMAPI	GetShadowBuffer (int32 bufferIndex, I3DShCamera **camera, TBBox2D &uvBox)=0
virtual boolean MCCOMAPI	IsVisibleInPerspective ()=0
virtual I3DShTreeElement *MCCOMAPI	GetTreeElement ()=0

Detailed Description

Light sources define the lighting in a 3D scene. All kind of light sources can be designed: spot lights, bulb lights, distant lights (sun, moon), etc. Various features can be coded in a Light Source Extension, because the Light Source has complete control of the light intensity returned to the 3D Shell.

Light sources create light that illuminate object surfaces. The user can combine lights with gels to make additional lighting effects (see the I3DExLightsourceGel interface).

The structure of a light is a little bit more complex that the typical component. It is similar to the structure of Cameras and Primitives.

There are 2 COM objects to consider:

The Light Instance that supports I3DShLightsource, I3DShInstance and I3DShTreeElement.
The Light Component that supports IShComponent, I3DExLightsource and I3DShTreeElementMember

For advanced users: You should note that there are actually 3 C++ object (The light instance, the light component and the external light). However the light component and the external light are aggregated by COM which means that you can be considered as one single COM object).

To get a pointer to a I3DShLightsource from a I3DExLightsource, you can use the following code:

    TMCCountedPtr<I3DShTreeElementMember> lightComponent;
    exLight->QueryInterface(IID_I3DShTreeElementMember,(void**)&lightComponent);
    ThrowIfNil(lightComponent);
   
    TMCCountedPtr<I3DShTreeElement> lightTree;
    lightComponent->GetTreeElement(&lightTree);
    ThrowIfNil(lightTree);
   
    TMCCountedPtr<I3DShLightsource> shLight;
    lightTree->QueryInterface(IID_I3DShLightsource.(void**)&shLight);

To access I3DExLightsource from I3DShLightsource, you can use the following code:

    TMCCountedPtr<IShComponent> lightComponent;
    shLight->GetLightComponent(&lightComponent);
    ThrowIfNil(lightComponent);
   
    TMCCountedPtr<I3DExLightsource> exLight;
    lightComponent->QueryInterface(IID_I3DExLightsource,(void**)&exLight);

This code might seem a bit complicated at first but it is actually simple. You have two COM objects that point on each other. I3DShLightsource::GetLightComponent() and I3DShTreeElementMember::GetTreeElement() allow you to get a pointer from one object to the other. The rest is only calling QueryInterface to get the right interface on each object.

Whenever it is possible you should use the Shell interface (I3DShLightsource) to access the light because the Shell will make sure that the parameter map of the external component is valid. This is especially important if the component is animated. For more information on components see the Overview of the SDK.

See also:: I3DExLightsource

Member Function Documentation

virtual MCCOMErr MCCOMAPI I3DShLightsource::ForEachShadowBuffer ( ForEachShadowBufferCallback proc,

void * priv

) [pure virtual]

Deprecated:
Use GetShadowBuffer() instead.

virtual boolean MCCOMAPI I3DShLightsource::GetColor ( const TVector3 & position,

const TVector3 & direction,

const real distance,

TMCColorRGB & result,

real & shadowIntensity

) [pure 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:

position 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.

virtual boolean MCCOMAPI I3DShLightsource::GetDirection ( const TVector3 & position,

TVector3 & resultDirection,

real & resultDistance

) [pure 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 position 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:

position 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

virtual void MCCOMAPI I3DShLightsource::GetExShadowFeature ( I3DExShadowFeature ** feature ) [pure virtual]

Returns a pointer to the external Shadow feature. This call is equivalent to calling GetShShadowFeature and then QueryInterface(IID_I3DExShadowFeature,...) on the result.

Parameters:

feature A pointer to the shadow feature.

virtual void MCCOMAPI I3DShLightsource::GetGelComponent ( I3DShLightsourceGel ** gel ) [pure virtual]

Returns the Gel component attached to this light.

Parameters:

gel The gel component.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetLightComponent ( IShComponent ** component ) [pure virtual]

Returns a pointer to the light component associated with this instance.

Parameters:

component A pointer to the light component.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetLightGlobalTransform ( TTransform3D * transform ) [pure virtual]

Returns the global transform of the light.

Parameters:

transform The global transform of the light.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetLightInfo ( boolean & hasLightCone,

boolean & hasLightSphere,

real & halfAngle,

TTransform3D & transform

) [pure virtual]

Returns information about light cones and sphere...

Parameters:

hasLightCone True on exit if the light supports a light cone (spot lights)

hasLightSphere True on ext if the light supports a light sphere (bulb lights)

halfAngle Half angle of the light cone if there is one

transform Global Transform of the light.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetLightParameter ( int32 keyword,

void * parameter

) [pure virtual]

Returns the value of a given parameter of the light.

Parameters:

keyword The identifier of the parameter

parameter A point to a buffer that can store the parameter value.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetNewTrace ( int16 & nb,

TLightTraceElement *& traceElem

) [pure virtual]

Deprecated:

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetPrimitiveID ( int32 & primID ) [pure virtual]

Returns the ID of the primitive that is displayed in place of the light.

Parameters:

primID The ID of the primitive that is displayed in place of the light.

virtual void MCCOMAPI I3DShLightsource::GetRandomRay ( int32 regionIndex,

Ray3D & ray

) [pure 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:

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

ray A reference to the ray that should be returned

virtual void MCCOMAPI I3DShLightsource::GetShadowBuffer ( int32 bufferIndex,

I3DShCamera ** camera,

TBBox2D & uvBox

) [pure 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

virtual int32 MCCOMAPI I3DShLightsource::GetShadowBufferCount ( ) [pure virtual]

Returns the number of shadow buffer needed for this light

virtual void MCCOMAPI I3DShLightsource::GetShShadowFeature ( I3DShShadowFeature ** feature ) [pure virtual]

Returns the Shadow feature attached to this light.

Parameters:

feature A pointer to the shadow feature.

virtual MCCOMErr MCCOMAPI I3DShLightsource::GetStandardLight ( TStandardLight & light ) const [pure 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

virtual I3DShTreeElement* MCCOMAPI I3DShLightsource::GetTreeElement ( ) [pure virtual]

Returns the I3DShTreeElement interface. This call is faster than calling QueryInterface.

virtual I3DExLightsource* MCCOMAPI I3DShLightsource::GetValidExLightNoAddRef ( ) [pure virtual]

Returns a valid external light for the current time (to by pass the app for speed) You should use this call with extreme caution: It assumes nothing will be changed in the scene while you use the external interface. In particular, if the time is changed you should call this function to get a new pointer.

Returns:
A pointer to a valid external light source. Not that it returns null if the light is not active in the current scene.

virtual void MCCOMAPI I3DShLightsource::InitSampling ( const TBBox3D & sceneBoundingBox,

real & solidAngle,

int32 & regionCount

) [pure 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)

virtual boolean MCCOMAPI I3DShLightsource::IsVisibleInPerspective ( ) [pure 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.

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetGelComponent ( I3DShLightsourceGel * gel,

ECloneMode cloneMode

) [pure virtual]

Sets the Gel component attached to this light.

Parameters:

gel The gel component

cloneMode The clone mode (see ECloneMode)

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetGelComponentByID ( int32 kindID ) [pure virtual]

Sets the type of Gel component attached to this light.

Parameters:

kindID The class ID of the Gel attached to this light

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetLightComponent ( IShComponent * component,

ECloneMode cloneMode

) [pure virtual]

Sets the light component associated with this instance.

Parameters:

component A pointer to the light component.

cloneMode The clone mode (see ECloneMode).

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetLightComponentByID ( int32 kindID ) [pure virtual]

Sets the type of the light (Buld, Distance, Spot...).

Parameters:

kindID The Class ID of the light.

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetShadowFeature ( I3DShShadowFeature * feature,

ECloneMode cloneMode

) [pure virtual]

Sets the Shadow feature attached to this light.

Parameters:

feature A pointer to the shadow feature.

cloneMode The clone mode (see ECloneMode)

virtual MCCOMErr MCCOMAPI I3DShLightsource::SetShadowFeatureByID ( int32 kindID ) [pure virtual]

Sets the type of Shadow feature attached to this light.

Parameters:

kindID The class ID of the Shadow feature attached to this light

The documentation for this struct was generated from the following file:

I3DShLightSource.h

Generated on Mon Mar 14 12:29:02 2005 for Carrara SDK Doc by

1.3.9.1

I3DShLightsource Struct Reference [Shell Interfaces]

Public Member Functions

Detailed Description

Member Function Documentation

I3DShLightsource Struct Reference
[Shell Interfaces]