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76 lines
3.0 KiB
Plaintext
76 lines
3.0 KiB
Plaintext
This file is part of a sample implementation of the analytical skylight and
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solar radiance models presented in the SIGGRAPH 2012 paper
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"An Analytic Model for Full Spectral Sky-Dome Radiance"
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and the 2013 IEEE CG&A paper
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"Adding a Solar Radiance Function to the Hosek Skylight Model"
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both by
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Lukas Hosek and Alexander Wilkie
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Charles University in Prague, Czech Republic
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Version: 1.4a, February 22nd, 2013
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Version history:
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1.4a February 22nd, 2013
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Removed unnecessary and counter-intuitive solar radius parameters
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from the interface of the colourspace sky dome initialisation functions.
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1.4 February 11th, 2013
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Fixed a bug which caused the relative brightness of the solar disc
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and the sky dome to be off by a factor of about 6. The sun was too
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bright: this affected both normal and alien sun scenarios. The
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coefficients of the solar radiance function were changed to fix this.
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1.3 January 21st, 2013 (not released to the public)
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Added support for solar discs that are not exactly the same size as
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the terrestrial sun. Also added support for suns with a different
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emission spectrum ("Alien World" functionality).
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1.2a December 18th, 2012
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Fixed a mistake and some inaccuracies in the solar radiance function
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explanations found in ArHosekSkyModel.h. The actual source code is
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unchanged compared to version 1.2.
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1.2 December 17th, 2012
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Native RGB data and a solar radiance function that matches the turbidity
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conditions were added.
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1.1 September 2012
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The coefficients of the spectral model are now scaled so that the output
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is given in physical units: W / (m^-2 * sr * nm). Also, the output of the
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XYZ model is now no longer scaled to the range [0...1]. Instead, it is
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the result of a simple conversion from spectral data via the CIE 2 degree
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standard observer matching functions. Therefore, after multiplication
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with 683 lm / W, the Y channel now corresponds to luminance in lm.
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1.0 May 11th, 2012
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Initial release.
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Please visit http://cgg.mff.cuni.cz/projects/SkylightModelling/ to check if
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an updated version of this code has been published!
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This archive contains the following files:
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README.txt This file.
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ArHosekSkyModel.h Header file for the reference functions. Their
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usage is explained there, and sample code for
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calling them is given.
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ArHosekSkyModel.c Implementation of the functions.
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ArHosekSkyModelData_Spectral.h Spectral coefficient data.
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ArHosekSkyModelData_CIEXYZ.h CIE XYZ coefficient data.
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ArHosekSkyModelData_RGB.h RGB coefficient data.
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Please note that the source files are in C99, and you have to set appropriate
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compiler flags for them to work. For example, when compiling this code with
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gcc, you have to add the "-std=c99" or "-std=gnu99" flags. |