Publicação
Rendering the Sky
| Resumo: | The appearance of the sky is defined by the position of the elements we can see in it. With that in mind, it’s interesting to comprehensively understand the procedures needed to accurately compute the position of said elements in the sky, given the latitude, longitude of the observer and the date. Alongside the accurate position of these elements, we can take into consideration the atmospheric scattering and attenuation, as well as taking advantage of our virtual environment to implement non-realistic features that enhance the visualization experience. Two applications, one for desktop and for Android, were developed using multiple free publicly available tools and resources. The 3 most relevant resources are a star catalogue (Nash), giving us the positions of over 140.000 stars, the set of equations presented in Paul Schlyter’s website (Schlyter) which compute the positions of the planets of the Solar System, and the SAMPA algorithm developed by NREL (2012). The latter both computes the position of the Sun and Moon and allows us to translate the position of celestial elements from a geocentric coordinate system to a topocentric one. This thesis mostly focuses on describing how to use these resources to accurately compute the position of and display the stars, planets, Moon and Sun. Besides the accurate positioning of these elements, atmospheric scattering is also taken into account, during the day, which gives our sky its familiar color, as well as atmospheric attenuation, during the night, which color shifts the planets, Moon and stars depending on their position on the sky. For ease of visualiza tion, non-realistic features were added that increase the visibility of usually imperceptible elements, such as increasing the scale of the planets, increasing the brightness of the dimmest stars and overlaying the artwork of the 88 constellations over the night sky. |
|---|---|
| Autores principais: | Fernandes, Pedro Miguel Machado |
| Assunto: | Atmospheric scattering Night sky Stars Real time simulation Dispersão atmosférica Céu noturno Estrelas Simulação em tempo real |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | The appearance of the sky is defined by the position of the elements we can see in it. With that in mind, it’s interesting to comprehensively understand the procedures needed to accurately compute the position of said elements in the sky, given the latitude, longitude of the observer and the date. Alongside the accurate position of these elements, we can take into consideration the atmospheric scattering and attenuation, as well as taking advantage of our virtual environment to implement non-realistic features that enhance the visualization experience. Two applications, one for desktop and for Android, were developed using multiple free publicly available tools and resources. The 3 most relevant resources are a star catalogue (Nash), giving us the positions of over 140.000 stars, the set of equations presented in Paul Schlyter’s website (Schlyter) which compute the positions of the planets of the Solar System, and the SAMPA algorithm developed by NREL (2012). The latter both computes the position of the Sun and Moon and allows us to translate the position of celestial elements from a geocentric coordinate system to a topocentric one. This thesis mostly focuses on describing how to use these resources to accurately compute the position of and display the stars, planets, Moon and Sun. Besides the accurate positioning of these elements, atmospheric scattering is also taken into account, during the day, which gives our sky its familiar color, as well as atmospheric attenuation, during the night, which color shifts the planets, Moon and stars depending on their position on the sky. For ease of visualiza tion, non-realistic features were added that increase the visibility of usually imperceptible elements, such as increasing the scale of the planets, increasing the brightness of the dimmest stars and overlaying the artwork of the 88 constellations over the night sky. |
|---|