The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2024
Filed:
Sep. 14, 2020
Nanjing Institute of Astronomical Optics & Technology, National Astronomical Observatories, Cas, Jiangsu, CN;
Yi Zheng, Jiangsu, CN;
Kai Wei, Jiangsu, CN;
Bin Liang, Jiangsu, CN;
Ying Li, Jiangsu, CN;
Changpeng Ding, Jiangsu, CN;
Abstract
The invention discloses a method for rendering on the basis of hemispherical orthogonal function, the method comprising the following steps: selecting rendering fragments and establishing a local coordinate system; acquiring a bidirectional reflectance distribution function of a material; if global illumination is an orthogonal function, determining a rotation matrix of an orthogonal function coefficient according to the rotation angles of the global coordinate system and the local coordinate system, and calculating a local orthogonal function illumination coefficient; converting the local orthogonal function illumination coefficient into a hemispherical orthogonal function illumination coefficient; sampling to obtain the spatial distribution of a bidirectional reflection distribution function of a rendered material; obtaining a hemispherical orthogonal function of the bidirectional reflection distribution function of the rendered material; and using the dot product of a hemispherical orthogonal function coefficient of illumination and a hemispherical orthogonal function coefficient of the bidirectional reflection distribution function of the rendered material and accumulating to obtain the light intensity in the reflection direction. A hemispherical harmonic function(HSH) is used to fit measurement data or theoretically derived data of a BRDF, which may avoid the difficulty of fitting that accurs for a hemispherical harmonics function due to data being missing in the lower hemisphere.