POINT OF VIEW SELECTION IN VIRTUAL 3D ENVIRONMENT
First Claim
1. A method of positioning a virtual camera in a 3D computer generated environment comprising a plurality of objects defined as a plurality of voxels, such positioning affording a view of a selected one of said objects with minimum occlusion from the other said objects, said method comprising:
- calculating a total occlusion value for each of a plurality of predefined virtual camera positions with respect to a reference point within said selected object, wherein each said total occlusion value is determined by calculating the respective path from each said virtual camera position to the reference point, and identifying each voxel along said path,calculating an occlusion value for each voxel along each said respective path by multiplying that voxel'"'"'s density by a transfer function value defined for that respective density,summing the occlusion values determined for all voxels along each said respective path calculated for a respective said predefined virtual camera position to obtain a total path occlusion value,selecting the predefined virtual camera position corresponding to the path with the lowest total path occlusion value, andenabling display of a graphical representation of said 3D computer generated environment corresponding to said selected predefined virtual camera position.
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Accused Products
Abstract
In a crowded representation of a virtual three dimensional space defined in terms of voxels, an object of interest will often be occluded by one or more objects of varying densities between the virtual camera defining the user'"'"'s point of view, and the object of interest. To automatically identify an optimal camera position, an number of candidate positions are considered, for example situated at the vertices of a regular polyhedron centred on the object of interest. For each of these candidate positions, a ray is cast towards the object of interest, and the occlusion for each intervening voxel is determined as the product of that voxel'"'"'s density, and a density transfer function. The virtual camera position corresponding to the least occluded path is then selected as the new point of view.
15 Citations
15 Claims
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1. A method of positioning a virtual camera in a 3D computer generated environment comprising a plurality of objects defined as a plurality of voxels, such positioning affording a view of a selected one of said objects with minimum occlusion from the other said objects, said method comprising:
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calculating a total occlusion value for each of a plurality of predefined virtual camera positions with respect to a reference point within said selected object, wherein each said total occlusion value is determined by calculating the respective path from each said virtual camera position to the reference point, and identifying each voxel along said path, calculating an occlusion value for each voxel along each said respective path by multiplying that voxel'"'"'s density by a transfer function value defined for that respective density, summing the occlusion values determined for all voxels along each said respective path calculated for a respective said predefined virtual camera position to obtain a total path occlusion value, selecting the predefined virtual camera position corresponding to the path with the lowest total path occlusion value, and enabling display of a graphical representation of said 3D computer generated environment corresponding to said selected predefined virtual camera position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. (canceled)
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14. An apparatus adapted to position a virtual camera in a 3D computer generated environment comprising a plurality of objects defined as a plurality of voxels, such positioning affording a view of a selected one of said objects with minimum occlusion from the other said objects, said apparatus being adapted to calculate a total occlusion value for each of a plurality of predefined virtual camera positions with respect to a reference point within said selected object, wherein each said total occlusion value is determined by calculating the respective path from each said virtual camera position to the reference point, and identifying each voxel along said path,
calculating an occlusion value for each voxel along each said respective path by multiplying that voxel'"'"'s density by a transfer function value defined for that respective density, said apparatus being further adapted to sum the occlusion values determined for all voxels along each said respective path calculated for a respective said predefined virtual camera position to obtain a total path occlusion value; - said apparatus being still further adapted to select the predefined virtual camera position corresponding to the path with the lowest total path occlusion value, said apparatus being further adapted to enable display of a graphical representation of said 3D computer generated environment corresponding to said selected predefined virtual camera position.
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15. A computer program stored on a non-transitory medium for positioning a virtual camera in a 3D computer generated environment comprising a pluralit of objects defined as a plurality of voxels, such positioning affording a view of a selected one of said objects with minimum occlusion from the other said objects, said computer program having computing instructions for:
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calculating a total occlusion value for each of a plurality of predefined virtual camera positions with respect to a reference point within said selected object, wherein each said total occlusion value is determined by calculating the respective path from each said virtual camera position to the reference point, and identifying each voxel along said path, calculating an occlusion value for each voxel along each said respective path by multiplying that voxel'"'"'s density by a transfer function value defined for that respective density, summing the occlusion values determined for all voxels along each said respective path calculated for a respective said predefined virtual camera position to obtain a total path occlusion value, selecting the predefined virtual camera position corresponding to the path with the lowest total path occlusion value, and. enabling display of a graphical representation of said 3D computer generated environment corresponding to said selected predefined virtual camera position.
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Specification