helios::PragueSkyModelInterface Class Reference

Wrapper class providing Helios-friendly interface to Prague Sky Model. More...

#include <PragueSkyModelInterface.h>

Public Member Functions
	PragueSkyModelInterface ()
	Constructor - creates uninitialized interface.
	~PragueSkyModelInterface ()
	Destructor - cleans up Prague model instance.
void	initialize (const std::string &dataset_path)
	Initialize the Prague Sky Model with dataset file.
bool	isInitialized () const
	Check if model has been initialized.
float	getSkyRadiance (const vec3 &view_direction, const vec3 &sun_direction, float wavelength_nm, float visibility_km, float albedo=-1.0f) const
	Get sky radiance at a single wavelength and direction.
float	computeIntegratedSkyRadiance (const vec3 &view_direction, const vec3 &sun_direction, float visibility_km, const std::vector< vec2 > &camera_response, float albedo=-1.0f) const
	Compute sky radiance integrated over camera spectral response.
void	getAvailableRanges (float &min_wavelength_nm, float &max_wavelength_nm, float &min_visibility_km, float &max_visibility_km, float &min_elevation_deg, float &max_elevation_deg) const
	Get available data ranges from loaded dataset.

Static Public Member Functions
static float	turbidityToVisibility (float turbidity)
	Convert Helios turbidity (AOD) to Prague visibility (km)

Detailed Description

Wrapper class providing Helios-friendly interface to Prague Sky Model.

This class:

• Manages Prague model instance lifecycle
• Loads reduced dataset on initialization
• Handles coordinate system conversions (Helios ↔ Prague)
• Converts turbidity (AOD) to visibility (km)
• Integrates sky radiance over camera spectral response
• Converts Prague exceptions to helios_runtime_error

Definition at line 46 of file PragueSkyModelInterface.h.

Constructor & Destructor Documentation

PragueSkyModelInterface()

PragueSkyModelInterface::PragueSkyModelInterface

(

)

Constructor - creates uninitialized interface.

Definition at line 28 of file PragueSkyModelInterface.cpp.

~PragueSkyModelInterface()

PragueSkyModelInterface::~PragueSkyModelInterface

(

)

Destructor - cleans up Prague model instance.

Definition at line 32 of file PragueSkyModelInterface.cpp.

Member Function Documentation

computeIntegratedSkyRadiance()

float PragueSkyModelInterface::computeIntegratedSkyRadiance	(	const vec3 &	view_direction,
		const vec3 &	sun_direction,
		float	visibility_km,
		const std::vector< vec2 > &	camera_response,
		float	albedo = -1.0f
	)		const

Compute sky radiance integrated over camera spectral response.

Integrates: ∫ L(λ) × R(λ) dλ / ∫ R(λ) dλ where L(λ) is sky radiance and R(λ) is camera spectral response.

Parameters

[in]	view_direction	Viewing direction (normalized vector)
[in]	sun_direction	Sun direction (normalized vector)
[in]	visibility_km	Atmospheric visibility in kilometers
[in]	camera_response	Camera spectral response [(lambda_nm, response), ...] Must be sorted by wavelength. Response values are unitless (0-1).
[in]	albedo	Ground albedo [0-1] (optional, uses dataset default if <0)

Returns

Integrated sky radiance in W/m²/sr

Note

Uses trapezoidal integration with automatic wavelength sampling

Definition at line 156 of file PragueSkyModelInterface.cpp.

getAvailableRanges()

void PragueSkyModelInterface::getAvailableRanges	(	float &	min_wavelength_nm,
		float &	max_wavelength_nm,
		float &	min_visibility_km,
		float &	max_visibility_km,
		float &	min_elevation_deg,
		float &	max_elevation_deg
	)		const

Get available data ranges from loaded dataset.

Parameters

[out]	min_wavelength_nm	Minimum wavelength (nm)
[out]	max_wavelength_nm	Maximum wavelength (nm)
[out]	min_visibility_km	Minimum visibility (km)
[out]	max_visibility_km	Maximum visibility (km)
[out]	min_elevation_deg	Minimum solar elevation (degrees)
[out]	max_elevation_deg	Maximum solar elevation (degrees)

Note

Throws helios_runtime_error if model not initialized

Definition at line 227 of file PragueSkyModelInterface.cpp.

getSkyRadiance()

float PragueSkyModelInterface::getSkyRadiance	(	const vec3 &	view_direction,
		const vec3 &	sun_direction,
		float	wavelength_nm,
		float	visibility_km,
		float	albedo = -1.0f
	)		const

Get sky radiance at a single wavelength and direction.

Parameters

[in]	view_direction	Viewing direction (normalized vector)
[in]	sun_direction	Sun direction (normalized vector from origin to sun)
[in]	wavelength_nm	Wavelength in nanometers [360-1480 nm]
[in]	visibility_km	Atmospheric visibility in kilometers [20-131.8 km]
[in]	albedo	Ground albedo [0-1] (optional, uses dataset default if <0)

Returns

Sky radiance in W/m²/sr/nm

Note

Throws helios_runtime_error if:

• Model not initialized
• Wavelength outside dataset range
• Visibility outside dataset range

Definition at line 105 of file PragueSkyModelInterface.cpp.

initialize()

void PragueSkyModelInterface::initialize

(

const std::string &

dataset_path

)

Initialize the Prague Sky Model with dataset file.

Parameters

[in]

dataset_path

Absolute path to Prague dataset (.dat file)

Note

Fails with helios_runtime_error if:

• Dataset file not found
• Dataset read error
• Already initialized

Definition at line 37 of file PragueSkyModelInterface.cpp.

isInitialized()

bool PragueSkyModelInterface::isInitialized

(

)

const

Check if model has been initialized.

Returns

true if initialize() was called successfully

Definition at line 70 of file PragueSkyModelInterface.cpp.

turbidityToVisibility()

float PragueSkyModelInterface::turbidityToVisibility ( float  turbidity )

static

Convert Helios turbidity (AOD) to Prague visibility (km)

Uses Koschmieder formula: V ≈ 3.9 / turbidity Clamps result to Prague dataset range [20, 131.8 km]

Parameters

[in]

turbidity

Ångström aerosol optical depth at 500 nm

Returns

Visibility in kilometers

Definition at line 208 of file PragueSkyModelInterface.cpp.

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The documentation for this class was generated from the following files:

• plugins/solarposition/include/PragueSkyModelInterface.h
• plugins/solarposition/src/PragueSkyModelInterface.cpp