PanoRendo is an HTML/JS application which can be accessed by the WEB browser of any device to simulate the sky appearance in color, both for daylight & twilight. Parameters such as Sun position, observer altitude and haze can be freely modified (JavaScript must be enabled). PanoRendo has three different tone-mapping options with adjustable brightness. The view screen can be chosen as panoramic to cover all of the sky, or zoomed to explore the horizon in detail for the twilight. Besides the rectangular views, it incorporates a fish-eye mode as well. PanoRendo uses a fast single-pass rendering algorithm. Detailed explanation about the employed sky model can be found in the relevant paper. A spreadsheet in MS Excel format is also available.


Sun Elevation and Sun Azimuth angles can be altered between -20° ~ +90° and -180° ~ +180°, respectively. The elevation above sea level can be entered into the Altitude box. The Haze field changes the turbidity of the air. The value "1" implies a clean & dry atmosphere (pure Rayleigh scattering). Any greater value scales the amount of aerosol (Mie scattering). When the value is set to "0", the Martian sky will be simulated. The luminance can be boosted by increasing the value in the Luma field as to analyze e.g. a twilight condition in depth. The sample picture above is a panoramic snapshot for a sunset, where the Venus Belt can be discriminated. The below one is a zoomed view for a hazy sunrise.


Three different tone-mapping functions are available through the drop-down menu Tone Map, namely "Reinhard", "sRGB" or "linear". Using the Zoom field, the magnification of the equi-rectangular projection can be changed. "1" enforces full panoramic Field-of-View (360° x 90°), while higher values shrink the range. If the value is set to "0", the polar equidistant projection is implemented causing a fish-eye view, with the zenith at center and the horizon on circumference, as shown below.



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