This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examinati...This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examination, can rapidly remove the irrelevant parts in a scene and find the vertices which fall into the shadow area of a given object. It is an effective alternative to the conventional shadow feeler method.展开更多
The effective temperature of the solar photosphere is usually obtained according to the solar constant, based on the Stefan-Boltzmann law. However its temperature distribution is not homogeneous. A hopeful way to obta...The effective temperature of the solar photosphere is usually obtained according to the solar constant, based on the Stefan-Boltzmann law. However its temperature distribution is not homogeneous. A hopeful way to obtain the area-temperature distribution of the solar photosphere is to solve the Black-body Radiation Inversion (BRI) problem. In this paper, a new practical solution method for BRI is developed. The theoretical analysis and numerical calculations show the low-temperature distribution difficulty of BRI is solved by this new method. Then the area-temperature distribution of the solar photosphere is obtained, according to the measured absolute solar spectral irradiance. It is the first realization of BRI for a real system after almost three decades of efforts. The results are comparable to that from the Stefan-Boltzmann law.展开更多
文摘This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examination, can rapidly remove the irrelevant parts in a scene and find the vertices which fall into the shadow area of a given object. It is an effective alternative to the conventional shadow feeler method.
基金supported by the National Natural Science Foundation of China (Grand Nos. 10675031, 10375012 and 19975009)supported in part by the Department of Education of Zhejiang Province (Grant No. Y200906911)
文摘The effective temperature of the solar photosphere is usually obtained according to the solar constant, based on the Stefan-Boltzmann law. However its temperature distribution is not homogeneous. A hopeful way to obtain the area-temperature distribution of the solar photosphere is to solve the Black-body Radiation Inversion (BRI) problem. In this paper, a new practical solution method for BRI is developed. The theoretical analysis and numerical calculations show the low-temperature distribution difficulty of BRI is solved by this new method. Then the area-temperature distribution of the solar photosphere is obtained, according to the measured absolute solar spectral irradiance. It is the first realization of BRI for a real system after almost three decades of efforts. The results are comparable to that from the Stefan-Boltzmann law.
