Portal Extraction Based on an Opening Labeling for Ray Tracing

Laurent Noël (1) , Venceslas Biri (1)

1 LIGM - Laboratoire d'Informatique Gaspard-Monge

Rendering photo-realistic images from a 3D scene description remains a challenging problem when processing complex geometry exposing many occlusions. In that case, simulating light propagation requires hours to produce a correct image. An opening map can be used to extract information from the geometry of the empty space of a scene, where light travels. It describes local thickness and allows to identify narrow regions that are difficult to traverse with ray tracing. We propose a new method to extract portals in order to improve rendering algorithms based on ray tracing. This method is based on the opening map, which is used to define a labeling of the empty space. Then portals-2D surfaces embedded in empty space-are extracted from labeled regions. We demonstrate that those portals can be sampled in order to explore the scene efficiently with ray tracing.

Mots clés: ray tracing; opening map; labeling; portals

Domaines: Synthèse d'image et réalité virtuelle [cs.GR]; Traitement des images [eess.IV]

Laurent Noël, Venceslas Biri. Portal Extraction Based on an Opening Labeling for Ray Tracing. 12th International Symposium, ISMM 2015, May 2015, Reykjavik, Iceland. ⟨10.1007/978-3-319-18720-4_3⟩. ⟨hal-01159795⟩