SoPathTracerAreaLight

InventorModule

author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	SoPathTracer
definition	SoPathTracer.def

Purpose

The SoPathTracerAreaLight module provides a physically based area light that illuminates the scene of a SoPathTracer. The lights can be rectangular or discs and have an area, color and intensity. They can be positioned with spherical coordinates around the bounding box of the renderer, or they can be position in world or camera space.

Since the light is physically modeled, it has a quadratic falloff. By default, the light intensity is adapted depending on the distance of the light to the center of the bounding box, so that the same intensity reaches the center of the bounding box.

There can be many area lights, but the performance will drop noticeable when using too many lights. A future version of the renderer might offer better performance for many lights by using a bounding volume hierarchy for the lights.

Windows

Default Panel

Parameter Fields

Field Index

Altitude: Float	Intensity: Float
Attach light to camera: Bool	Mode: Enum
Azimuth: Float	Orientation: Rotation
Color: Color	Position: Vector3
Diameter: Float	Render source: Bool
Distance: Float	Scale Mode: Enum
Enabled: Bool	Type: Enum
Height: Float

Visible Fields

Enabled

name: enabled, type: Bool, default: TRUE

Enables the light.

Render source

name: renderSource, type: Bool, default: FALSE

Renders the light in the scene (only for debugging).

Color

name: color, type: Color, default: 1 1 1

The color of the light.

Intensity

name: intensity, type: Float, default: 5, minimum: 0, maximum: 20

The intensity of the light.

Diameter

name: width, type: Float, default: 0.5, minimum: 0.01, maximum: 5

The diameter of the disc (relative to the bounding box of the volume).

Height

name: height, type: Float, default: 0.5, minimum: 0.01, maximum: 5

The height of the rectangle (relative to the bounding box of the volume)

Altitude

name: theta, type: Float, default: 180

The spherical coordinate theta.

Azimuth

name: phi, type: Float, default: 45

The spherical coordinate phi.

Distance

name: distance, type: Float, default: 3.5, minimum: 0, maximum: 10

The distance of the light to the bounding box of the scene, relative to the bounding box diameter.

Attach light to camera

name: attachToCamera, type: Bool, default: FALSE

Attaches the light to the camera space instead of world space.

Position

name: position, type: Vector3, default: 0 0 0

The position of the light (world or camera space), when Mode is PositionAndOrientation.

Orientation

name: orientation, type: Rotation, default: 0 0 1 0

The orientation of the light (world or camera space), when Mode is PositionAndDirection.

Type

name: type, type: Enum, default: AreaLight_Rectangle

Shape of the light.

Values:

Title	Name	Description
Disc	AreaLight_Disc	Disc
Rectangle	AreaLight_Rectangle	Rectangle

Mode

name: mode, type: Enum, default: DistanceAndAngles

Selects the positioning mode.

Values:

Title	Name	Description
Position And Orientation	PositionAndOrientation	Light is positioned via position and orientation, in world or camera space depending on Attach light to camera.
Distance And Angles	DistanceAndAngles	Light is positioned around bounding box of the scene in given distance and with given spherical coordinates (angles).

Scale Mode

name: scaleMode, type: Enum, default: ScaleToBoundingSphere

The scaling of the light parameters.

Values:

Title	Name	Description
Scale To Bounding Sphere	ScaleToBoundingSphere	Scale light intensity and distance by the bounding sphere diameter.
Scaling Off	ScalingOff	No scaling.