{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9639976","patent":{"patent_number":"US-9639976","title":"Efficient computation of shadows for circular light sources","assignee":null,"inventors":[],"filing_date":"2014-10-31T00:00:00.000Z","publication_date":"2017-05-02T00:00:00.000Z","cpc_codes":["G06T","G06T","G06T","G06T","G06T","G06T","G06T"],"num_claims":20,"abstract":"Methods and apparatus are provided for displaying shadows of circular light sources. A computing device can determine a light source and an occluding polygon that is between the light source and a receiver surface, where the occluding polygon includes vertices connected by edges. The computing device can determine a shadow of the occluding polygon on the receiver surface by at least: determining, for a particular vertex, a projection vertex on the receiver surface by projecting a ray from the center point through the particular vertex; determining an outline polygon based on the projection vertex; determining a projection circle around the projection vertex; determining a penumbra of the shadow based on exterior tangents outside of the outline polygon; and determining an umbra of the shadow based on interior tangents inside the outline polygon. The computing device can display at least part of the shadow."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Efficient computation of shadows for circular light sources","description":"Methods and apparatus are provided for displaying shadows of circular light sources. A computing device can determine a light source and an occluding polygon that is between the light source and a rec","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9639976","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-9639976","citation_suggestion":"Patentable. \"Efficient computation of shadows for circular light sources\" (US-9639976). https://patentable.app/patents/US-9639976","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9639976","json":"https://patentable.app/api/llm-context/US-9639976","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T10:20:56.435Z"}