Visibility function of a three-dimensional scene

A non-transitory computer readable medium storing thereon a computer program comprising instructions for performing a computer-implemented method of computing of a visibility function of a three-dimensional (3D) scene, the method comprising:

• obtaining a set of directions ({right arrow over (ω)}) in the 3D scene;
• for each direction of the set, computing a set of lines that are parallel to the direction;
• for each computed set of lines, sampling the lines of the set into spatial segments;
• associating each line of a set with a bit field, each spatial segment of the line corresponding to a bit of the bit field;
• superimposing the set of lines and the 3D scene;
• when a spatial segment of a line intersects a geometry in the 3D scene, marking the bit corresponding to the spatial segment of the bit field associated with the line;
• obtaining two points in the 3D scene that define a query segment;
• identifying one or more spatial segments having a closest alignment with the query segment;
• and
• computing the visibility of the query segment by performing a logical bit operation on one or more bit fields of the lines the identified one or more spatial segments belong to.

A system comprising:

• a processor coupled to a memory and a graphical card with a graphics processing unit (GPU), the memory having recorded thereon a computer program comprising instructions for computing of a visibility function of a three-dimensional (3D) scene that when executed by the processor causes the processor to be configured to:
• obtain a set of directions ({right arrow over (ω)}) in the 3D scene;
• for each direction of the set, compute a set of lines that are parallel to the direction;
• for each computed set of lines, sample the lines of the set into spatial segments;
• associate each line of a set with a bit field, each spatial segment of the line corresponding to a bit of the bit field;
• superimpose the set of lines and the 3D scene;
• when a spatial segment of a line intersects a geometry in the 3D scene, mark the bit corresponding to the spatial segment of the bit field associated with the line;
• obtain two points in the 3D scene that define a query segment;
• identify one or more spatial segments having a closest alignment with the query segment;
• and
• compute the visibility of the query segment by performing a logical bit operation on one or more bit fields of the lines the identified one or more spatial segments belong to.