Abstract: A method and device for estimating the quantity of light received by an element of at least a participating medium belonging to a light ray crossing the at least a participating medium and having as origin a light source. As to optimize the estimation and the rendering of the at least a medium, the method comprises determining a pseudo-metric function according to intersection points between the participating medium and the light ray, the pseudo-metric function representing the distance only along the part(s) of the light ray crossing the participating medium; estimating first projection coefficients in a functions basis, the first coefficients being representative of an extinction function along the light ray according to the pseudo-metric function; and estimating the quantity of light received by the element according to the first projection coefficients.

Abstract: To compile a source program comprising first rule(s) not supported by a target environment and to enable the first rule(s) to be executed on the target environment, the method comprises generating a directed graph representative of the source program, generating a first data structure corresponding to a flat representation of the directed graph, first data structure comprising at least a first identifier associated with the at least a first rule, and generating a second data structure comprising first instructions adapted for interpreting the first data structure by using the at least a first identifier, the instructions being coded into a code supported by the target environment.

Abstract: A method for visualizing contact between a first object and at least a second object of a virtual scene commences by first associating a first identifier with first pixels associated with the first object and at least a second identifier with second pixels associated with the at least a second object. Thereafter, for at least one first pixel, at least a distance in world space between the at least one first pixel and at least one second pixel located in the neighbourhood of the at least one first pixel, is computed. Then at least a contact between the first object and the at least a second object is visualized if the at least a computed distance remains less than a first threshold distance.

Abstract: The invention relates to a method for estimation of information representative of a height. In order to minimize the required calculation time, the method comprises steps for: selection of a first point from among a plurality of points of a normal map, a normal being associated with each of the points of said plurality, a reference height being associated with said first point, estimation of a height difference between the first point and a second point of the normal map different from the first point according to the normal associated with the second point and the distance separating the first point from the second point in the normal map.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media, the light being transmitted by a light environment comprising a plurality of light sources. In order to improve the display while minimising the required calculation time, the method comprises steps for: estimation of first projection coefficients in an orthonormal basis of spherical functions, said first projection coefficients being representative of the reduction of light intensity in a point of said media, said estimation of first projection coefficients being carried out for each point of a first set of points of said media, and estimation of the quantity of light scattered by said media, according to at least one scattering direction of the light, using said first estimated projection coefficients.

Abstract: The invention is related to a method for processing a computer-animated scene, the computer-animated scene being represented with at least an animation graph, at least an animation graph comprising a plurality of nodes connected by paths, the paths being representative of dependencies between the nodes, at least an event being associated with each node, a first information representative of the type of each event being associated with each node. As to optimize the parallelization of the nodes, the method comprises a step of classifying the nodes in at least a first batch and at least a second batch according to the first information associated with each node, at least a first batch comprising nodes to be evaluated in parallel and at least a second batch comprising nodes to be evaluated sequentially.

Abstract: A method for estimating the quantity of light received by a point M of a heterogeneous participating media, the light being emitted by a light environment. Thereafter, the method comprises estimating, for each point of a first set of points, first values representative of the light attenuation between the considered point and a first surface bounding the media along a plurality of particular directions of light emission, estimating first coefficients of projection by projection of the first values of reduction of light intensity in an orthonormal basis of spherical functions, estimating second values representative of the light attenuation between the point and a second surface along directions, the second surface comprising some of the points of the neighbourhood of the point, and estimating the quantity of light received by the point using first coefficients of projection and second values of reduction of light intensity.

Abstract: A method for estimating occlusion in a virtual environment comprising at least two objects and observed from a viewpoint. Thereafter, a second item of information representative of the distance separating a second fragment of a second object from the viewpoint according to an observation direction is computed:, the second item of information is compared with a first item of information representative of the distance separating a first fragment of a first object from the viewpoint according to the observation direction and is stored in a first buffer memory. If the second item of information is less than the first item of information, then a third item of information representative of attributes associated with the second fragment is estimated, the second item of information is stored in a second buffer memory and the third item of information is stored in a third buffer memory.

Abstract: The invention relates to a method for estimating information representative of a pixel of a virtual object. In order to improve the rendering while minimizing the required calculation time, the method comprises defining a first surface element associated with the pixel according to a direction of observation of the virtual object, the first surface element belonging to a representation of the virtual object according to a first level of detail; associating a second surface element with the first surface element, the second surface element being determined by intersection between the direction of observation and a first parametric surface representing the virtual object according to a second level of detail; estimating the information representative of the pixel according to the second surface element and information associated with the second surface element enabling the virtual object to be represented according to a third level of detail.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media. In order to optimise the display while minimising the required calculation time, the method comprises steps for selecting at least one level of spatial subdivision of said media from among a plurality of hierarchic levels of spatial subdivision according to at least one item of error information representative of an attenuation difference in said media according to at least one direction between two consecutive hierarchic levels, and estimating the quantity of light scattered by sampling of said media along at least one scattering direction, the sampling being a function of at least one selected spatial subdivision level.

Abstract: A method for estimation of the quantity of light received at a point P of a virtual environment that comprises several first points lit by a light source, these first points forming a plurality of groups each comprising at least one first point is disclosed. In order to improve the display while minimizing the required calculation time, the method estimates the quantity of incident light received at point P by estimating a surface including point P grouping at least some of the points of the virtual environment, estimating a first group of points contributing to the lighting of point P by reflection of the incident light received from the light source based on occlusion information associated with the surface including point P and estimating the quantity of incident light received by the first group of point based on reflectance information associated with such group.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media. In order to improve the display while minimizing the required calculation time, the method comprises steps for estimating projection coefficients in a function database using values representative of density for a set of points of said media situated along at least one emission direction of light by a light source, and for estimating of the quantity of light scattered by said media, according to at least one diffusion direction of the light, using said estimated projection coefficients.

Abstract: The invention relates to a method for estimation of information representative of a height. In order to minimize the required calculation time, the method comprises steps for: selection of a first point from among a plurality of points of a normal map, a normal being associated with each of the points of said plurality, a reference height being associated with said first point, estimation of a height difference between the first point and a second point of the normal map different from the first point according to the normal associated with the second point and the distance separating the first point from the second point in the normal map.

Abstract: An environment map representative of lighting information of a real environment. As to enhance the impression of immersion into a virtual environment, the method comprises the steps of acquisition at real time of an image representative of a partial lighting information of said real environment from a digital optical acquisition device, said image comprising a plurality of pixels; and estimation of said environment map by extrapolation of at least a part of said pixels of said image, the extrapolation comprising the application of a first value corresponding to the mean value of the pixels of said image to at least a first part of the environment map.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media. In order to improve the display while minimising the required calculation time, the method comprises steps for: estimation of projection coefficients in a function basis using values representative of density for a set of points of said media that are situated along at least one emission direction of light by a light source, and estimation of the quantity of light scattered by said media, according to at least one scattering direction of the light, using said estimated projection coefficients.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media. In order to optimise the display while minimising the required calculation time, the method comprises steps for selecting at least one level of spatial subdivision of said media from among a plurality of hierarchic levels of spatial subdivision according to at least one item of error information representative of an attenuation difference in said media according to at least one direction between two consecutive hierarchic levels, and estimating the quantity of light scattered by sampling of said media along at least one scattering direction, the sampling being a function of at least one selected spatial subdivision level.

Abstract: The invention relates to a method for estimating the quantity of light scattered by a heterogeneous participating media, the light being transmitted by a light environment comprising a plurality of light sources. In order to improve the display while minimising the required calculation time, the method comprises steps for: estimation of first projection coefficients in an orthonormal basis of spherical functions, said first projection coefficients being representative of the reduction of light intensity in a point of said media, said estimation of first projection coefficients being carried out for each point of a first set of points of said media, and estimation of the quantity of light scattered by said media, according to at least one scattering direction of the light, using said first estimated projection coefficients.

Abstract: The invention relates to a method for estimation of the occlusion at a point P of a virtual environment, the point P belonging to a surface (S) grouping at least some of the points of the virtual environment visible from a viewpoint. In order to improve the display while minimising the required calculation time, the method comprises steps for: estimating intersections between said surface (S) and a plurality of half-lines having as origin said point P, said intersections being estimated by discretization of each half-line of said plurality of half-lines, associating of occlusion factors with the half-lines of said plurality of half-lines having an intersection with said surface (S), said occlusion factors being a function of occlusion distances ?0 separating said point P from said intersections, and estimation of the occlusion in said point P from said estimated intersections.

Abstract: As to generate shadows in an image, the method comprises the steps of: Computing a depth-map that comprises an array of pixels, wherein pixels in the depth-map are associated to a single value corresponding to depth value that indicates a depth from a light source to a portion of nearest occluding object visible through the pixel, projecting a point visible through a pixel of said image into a light space, the result of said projection being a pixel of said depth-map, calculating a distance between the said visible point and the light source, fetching the depth value associated to said pixel of depth-map, computing, for said pixel of said image, an adaptive bias as a function of a predetermined base bias and a relationship between the normal of a surface on which the said visible point is located and incident light direction at said visible point, comparing for said pixel in the image, the distance between said visible point and the light source with the sum of the corresponding depth map value and said ad

Abstract: The invention relates to a method for live construction of a video sequence comprising a modelled 3D object, the method comprising the following steps: pre-calculating data representative of at least one first image of a three-dimensional environment and a first item of associated depth information, live calculation of: data representative of at least one second image representing said modelled object on which is mapped a current image of a live video stream, and a second item of depth information associated with said at least one second image, and composing live said sequence by combining said at least one first image and said at least one second image according to said first and second items of depth information.