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Inverse Lambertian in a Given Direction

 

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Description


The Inverse Lambertian in a Given Direction apodization type scales all source rays by their direction to give an Inverse Lambertian intensity distribution.  This effectively apodizes the rays with a cos-1(f) factor, where f is the elevation angle in polar coordinates.  Note that if the source rays are set to be Lambertian on the Positions / Directions tab of the source dialog and then the Inverse Lambertian in a Given Direction apodization is chosen, the source intensity distribution would effectively be isotropic.  The following images show the source and intensity distribution for an isotropic plane of random rays emitting into a 90o cone half angle with the Inverse Lambertian in a Given Direction apodization applied.

 

 

 

Navigation


The Inverse Lambertian in a Given Direction directional apodization is available on the Power tab of a Detailed Source dialog.  From the Power tab, select "Inverse Lambertian in a Given Direction" from the drop down menu of directional apodization types.

 

 

Controls


The following table describes the available controls on the Power tab of a Detailed Source dialog.  Of interest to this help topic are the Direction Apodization parameter settings.

 

Control

Inputs / Description

Defaults

Total Power

Total power of the source after both the position and direction apodization functions have been applied to the rays.

1

Position Apodization

Type

Drop down menu of available position apodization options.

Uniform

Parameters

Dependent on selected Type.

 

Direction Apodization

Type

Drop down menu of available direction apodization options. Select "Inverse Lambertian in a Given Direction" from the drop down menu.

Uniform

Parameters

X

X component of the direction cosine vector for the direction about which the apodization is applied.

0

Y

Y component of the direction cosine vector for the direction about which the apodization is applied.

0

Z

Z component of the direction cosine vector for the direction about which the apodization is applied.

1

Angle

The Inverse Lambertian apodization factor, cos-1(f) , goes to infinity as f approaches 90o,  so this apodization is limited to angles less than 90o.  The Angle value specifies angular region over which the Inverse Lambertian Apodization is applied.

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OK

Accept settings and close the dialog box.

 

Cancel

Discard settings and close the dialog box.

 

Apply

Apply settings and keep the dialog box open.

 

Help

Access this Help page.

 

 

 

Related Topics


Direction Apodization - Uniform Unit Apodization

Direction Apodization - Lambertian in a given direction

Direction Apodization - Gaussian

Direction Apodization - cos^n or sin^n in a given direction

Direction Apodization - Sampled as a function of Spherical Angles 

 

 

 

 

 

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