TY - GEN
T1 - Modelling of clouds from a hemispherical image
AU - Alldieck, Thiemo
AU - Lundtoft, Dennis H.
AU - Montanari, Niels
AU - Nikolov, Ivan
AU - Vlaykov, Iskren G.
AU - Madsen, Claus B.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - This paper presents an image-based method for modelling clouds. Unlike previous image-based approaches, a hemispherical photograph is used as input, enabling to consider an entire sky instead of merely a portion. Our method computes the intensity and opacity of the clouds from the photograph. For this purpose, beforehand, the sun illumination is filtered, the pixels are classified between cloud and sky pixels, and the sky behind the clouds is reconstructed. After having been smoothed, the intensity of the clouds is used to create vertices on a hemisphere, and their radius coordinate is modulated by the intensity value of the corresponding pixel. Finally, the mesh is generated by triangulation of the vertices. Additionally, the use of the opacity of the clouds to simulate their transparency and render them is proposed. The results show that our method can be used to produce a realistic full sky populated with clouds in a very straightforward way for the user.
AB - This paper presents an image-based method for modelling clouds. Unlike previous image-based approaches, a hemispherical photograph is used as input, enabling to consider an entire sky instead of merely a portion. Our method computes the intensity and opacity of the clouds from the photograph. For this purpose, beforehand, the sun illumination is filtered, the pixels are classified between cloud and sky pixels, and the sky behind the clouds is reconstructed. After having been smoothed, the intensity of the clouds is used to create vertices on a hemisphere, and their radius coordinate is modulated by the intensity value of the corresponding pixel. Finally, the mesh is generated by triangulation of the vertices. Additionally, the use of the opacity of the clouds to simulate their transparency and render them is proposed. The results show that our method can be used to produce a realistic full sky populated with clouds in a very straightforward way for the user.
UR - http://www.scopus.com/inward/record.url?scp=85089470176&partnerID=8YFLogxK
U2 - 10.2312/cgvc.20141202
DO - 10.2312/cgvc.20141202
M3 - Article in proceeding
AN - SCOPUS:85089470176
T3 - TPCG 2014 - Theory and Practice of Computer Graphics, Proceedings
SP - 17
EP - 24
BT - TPCG 2014 - Theory and Practice of Computer Graphics, Proceedings
A2 - Borgo, Rita
A2 - Tang, Wen
PB - European Association for Computer Graphics
T2 - 2014 EG UK Theory and Practice of Computer Graphics Conference, TPCG 2014
Y2 - 10 September 2014 through 11 September 2014
ER -