A method and intersection testing module in a ray tracing system for determining whether a ray intersects a 3D axis-aligned box that represents a volume defined by a front-facing plane and a back-facing plane for each dimension. Scaled inverse ray components are determined and a scaled minimum culling distance is determined using a result of multiplying an unscaled minimum culling distance for the ray by a predetermined magnitude. Scaled intersection distances to the planes defining the box are determined using scaled inverse ray components. The largest of the determined scaled intersection distances to a front-facing plane of the box is identified. The smallest of the determined scaled intersection distances to a back-facing plane of the box is identified. It is determined that the ray intersects the box if all of three determinations are satisfied, and it is determined that the ray misses the box if one or more of the three determinations are not satisfied.

A method and an intersection testing module in a ray tracing system for performing intersection testing for a ray with respect to a plurality of convex polygons, each of which is defined by an ordered set of vertices, wherein at least one of the vertices is a shared vertex which is used to define at least two of the convex polygons. The vertices of the convex polygons are projected onto a pair of axes orthogonal to the ray direction. A vertex ordering scheme defines an ordering of the projected vertices which is independent of the ordering of the vertices in the ordered sets. For each of the convex polygons, for each edge of the convex polygon defined by two of the projected vertices, a parameter indicative of which side of the edge the ray passes on is determined, wherein if the ray is determined to intersect a point on the edge then the parameter is determined based upon whether the ordering of the projected vertices defining the edge matches the ordering of the vertices in the ordered set of vertices defining the convex polygon. Whether the ray intersects the convex polygon is determined based on the parameters determined for the edges of the convex polygon.

A method and an intersection testing module in a ray tracing system for performing intersection testing for a ray with respect to a plurality of convex polygons, each of which is defined by an ordered set of vertices. The vertices of the convex polygons are projected onto a pair of axes orthogonal to the ray direction. For each edge of a convex polygon defined by two of the projected vertices, a signed parameter is determined, wherein the sign of the signed parameter is indicative of which side of the edge the ray passes on. If the ray is determined to intersect a point on the edge then the sign of the signed parameter is determined using a module which is configured to: take as inputs, indications which classify each of p.sub.i, q.sub.i, p.sub.j and q.sub.j coordinates as negative, zero or positive, and output, for valid combinations of classifications of the p.sub.i, q.sub.i, p.sub.j and q.sub.j coordinates, an indication of the sign of the signed parameter. It is then determined whether the ray intersects the convex polygon based on the signs of the signed parameters determined for the edges of the convex polygon.

A method and an intersection testing module for performing intersection testing of a ray with a box in a ray tracing system. The ray and the box are defined in a 3D space using a space-coordinate system, and the ray is defined with a ray origin and a ray direction. A ray-coordinate system is used to perform intersection testing, wherein the ray-coordinate system has an origin at the ray origin, and the ray-coordinate system has three basis vectors. A first of the basis vectors is aligned with the ray direction. A second and a third of the basis vectors: (i) are both orthogonal to the first basis vector, (ii) are not parallel with each other, and (iii) have a zero as one component when expressed in the space-coordinate system. A result of performing the intersection testing is outputted for use by the ray tracing system.

A method and an intersection testing module for performing intersection testing of a ray with a convex polygon in a ray tracing system. The ray and the convex polygon are defined in a 3D space using a space-coordinate system. The ray is defined with a ray origin and a ray direction. A ray-coordinate system is used to perform intersection testing, wherein the ray-coordinate system has an origin at the ray origin, and wherein the ray-coordinate system has three basis vectors. A first of the basis vectors is aligned with the ray direction. A second and a third of the basis vectors: (i) are both orthogonal to the first basis vector, (ii) are not parallel with each other, and (iii) have a zero as one component when expressed in the space-coordinate system. A result of performing the intersection testing is outputted for use by the ray tracing system.

A method and intersection testing module in a ray tracing system for determining whether a ray intersects a 3D axis-aligned box that represents a volume defined by a front-facing plane and a back-facing plane for each dimension. Scaled inverse ray components are determined and a scaled minimum culling distance is determined using a result of multiplying an unscaled minimum culling distance for the ray by a predetermined magnitude. Scaled intersection distances to the planes defining the box are determined using scaled inverse ray components. The largest of the determined scaled intersection distances to a front-facing plane of the box is identified. The smallest of the determined scaled intersection distances to a back-facing plane of the box is identified. It is determined that the ray intersects the box if all of three determinations are satisfied, and it is determined that the ray misses the box if one or more of the three determinations are not satisfied.

A method and intersection testing module are provided in a ray tracing system for determining whether a ray intersects a 3D axis-aligned box. The box represents a volume defined by a front-facing plane and a back-facing plane for each of the dimensions of the three-dimensional axis-aligned box. Scaled ray components are determined, wherein a third scaled ray component equals 1. A scaled minimum culling distance and a scaled maximum culling distance are determined. Determined cross-multiplication values are used to identify which of the front-facing planes intersects the ray furthest along the ray and identify which of the back-facing planes intersects the ray least far along the ray. It is determined whether the ray intersects the identified front-facing plane of the box at a position that is no further along the ray than the position at which the ray intersects the identified back-facing plane.

An information processing apparatus creates a first virtual object expressing a physical object that is detected from physical object information obtained from a physical object information acquisition unit. The information processing apparatus determines a display state of the first virtual object in accordance with a result of detecting collision between the first virtual object and a second virtual object. The information processing apparatus creates, on the basis of a virtual space including the first virtual object and the second virtual object, position-orientation of an HMD, the determined display state, and a physical space image obtained from the HMD, a mixed reality image in combination of an image of the virtual space and the physical space image, and displays the created mixed reality image on the HMD.

A method and intersection testing module are provided in a ray tracing system for determining whether a ray intersects a 3D axis-aligned box. The box represents a volume defined by a front-facing plane and a back-facing plane for each of the dimensions of the three-dimensional axis-aligned box. Scaled ray components are determined, wherein a third scaled ray component equals 1. A scaled minimum culling distance and a scaled maximum culling distance are determined. Determined cross-multiplication values are used to identify which of the front-facing planes intersects the ray furthest along the ray and identify which of the back-facing planes intersects the ray least far along the ray. It is determined whether the ray intersects the identified front-facing plane of the box at a position that is no further along the ray than the position at which the ray intersects the identified back-facing plane.

Disclosed herein are an apparatus and method for generating a topological map for navigation of a robot. The method for generating a topological map for navigation of a robot, performed by the apparatus for building the topological map for the navigation of the robot, includes calculating the physical size of a single pixel on a metric map of a space in which a mobile robot is to navigate, extracting the physical coordinates of the pixel on the metric map, building node data and edge data for the navigation of the mobile robot using the physical coordinates, and generating a topological map for the navigation of the mobile robot based on the built node data and the built edge data.