# 7.27. Ray Trace Source

## 7.27.1. Raytrace Source

Scope

  Aria Region, Equation System, Explicit Equation System, Root Finder Equation System

Summary

  Specification of ray source to be used as part of a ray tracing boundary condition

    begin Raytrace Source Value

       Absorption Expression [For Band Band] {=} Value

       Absorption Model {=} {fresnel | specular}

       Banded Wavelength Model {=} Value

       Direction Function {=} Value

       Discretization {=} {monte_carlo | radial}

       Exponent {=} Value

       Exponential Factor {=} Value

       Flux Function [For Band Band] {=} Value

       Maximum Intersections {=} Value

       Minimum Power Ratio {=} Value

       Number Of Circular Segments {=} Value

       Number Of Radial Segments {=} Value

       Number Of Rays {=} Value

       Parallel Type {=} {ray | scene}

       Path Function {=} Value

       Power Function [For Band Band] {=} Value

       Radius {=} Value

       Type {=} {circular | circular_gaussian}

    end Raytrace Source Value

### 7.27.1.1. Line Commands

###### Absorption Expression

Syntax

  Absorption Expression [For Band Band] {=} Value

Summary

  Specify the expression to use to calculate the surface absorption properties

Parameter | Value | Default
--- | --- | ---
Band | string | –
{=} | {= | are | is} | –
Value | string | –

###### Absorption Model

Syntax

  Absorption Model {=} {fresnel | specular}

Summary

  Set the method for calculating ray interactions with surfaces. Valid values are ‘Specular’ and ‘Fresnel’

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | {fresnel | specular} | –

###### Banded Wavelength Model

Syntax

  Banded Wavelength Model {=} Value

Summary

  Specify a banded wavelength model to use for banded radiation

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | string | –

###### Direction Function

Syntax

  Direction Function {=} Value

Summary

  Specify the user function giving the 3 components of the travel direction for the rays as a function of time

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | string | –

###### Discretization

Syntax

  Discretization {=} {monte_carlo | radial}

Summary

  Set the method for discretizing the source into rays. Valid values are ‘Monte Carlo’ and ‘Radial’

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | {monte_carlo | radial} | –

###### Exponent

Syntax

  Exponent {=} Value

Summary

  Set the exponent for the Circular_Gaussian type. An exponent of 2 gives a standard Gaussian and is the default

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | integer | –

###### Exponential Factor

Syntax

  Exponential Factor {=} Value

Summary

  Set the exponential factor. Required for the Circular_Gaussian type

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | real | –

###### Flux Function

Syntax

  Flux Function [For Band Band] {=} Value

Summary

  Specify the user function giving the flux of the circular sources as a function of time

Parameter | Value | Default
--- | --- | ---
Band | string | –
{=} | {= | are | is} | –
Value | string | –

###### Maximum Intersections

Syntax

  Maximum Intersections {=} Value

Summary

  Set the number of times that a ray may intersect surfaces before it is no longer tracked. Default is 10

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | integer | –

###### Minimum Power Ratio

Syntax

  Minimum Power Ratio {=} Value

Summary

  Set the minimum fraction of initial power that a ray may have before it is no longer tracked. Default is 0.001

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | real | –

###### Number Of Circular Segments

Syntax

  Number Of Circular Segments {=} Value

Summary

  Set the number of segments to discretize the circle circumference into at the innermost radial segment. Required for the radial discretization type

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | integer | –

###### Number Of Radial Segments

Syntax

  Number Of Radial Segments {=} Value

Summary

  Set the number of segments to discretize the circle radius into. Required for the radial discretization type

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | integer | –

###### Number Of Rays

Syntax

  Number Of Rays {=} Value

Summary

  Set the number of rays to be generated by the circular sources. Required for the Monte Carlo discretization type

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | integer | –

###### Parallel Type

Syntax

  Parallel Type {=} {ray | scene}

Summary

  Set the parallel decomposition method for the ray tracer. Valid values are ‘Ray’ and ‘Scene’

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | {ray | scene} | –

###### Path Function

Syntax

  Path Function {=} Value

Summary

  Specify the user function giving the x, y, and z position of the circular sources as a function of time

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | string | –

###### Power Function

Syntax

  Power Function [For Band Band] {=} Value

Summary

  Specify the user function giving the power of the circular sources as a function of time

Parameter | Value | Default
--- | --- | ---
Band | string | –
{=} | {= | are | is} | –
Value | string | –

###### Radius

Syntax

  Radius {=} Value

Summary

  Set the radius for the circular shapes

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | real | –

###### Type

Syntax

  Type {=} {circular | circular_gaussian}

Summary

  Set the type of the ray source. Valid values are ‘Circular’ and ‘Circular_Gaussian’

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Value | {circular | circular_gaussian} | –