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