Abstract: A raycaster performs a raycasting algorithm, where the raycasting algorithm takes, as an input, a sparse hierarchical volumetric data structure. Performing the raycasting algorithm includes casting a plurality of rays from a reference point into the 3D volume, and, for each of the plurality of rays, traversing the ray to determine whether voxels in the set of voxels are intersected by the ray and are occupied, where the ray is to be traversed according to an approximate traversal algorithm.

Abstract: Blade (1) extending along a geometric axis (1gXY/1gYZ) from a root (111XY/111YZ) where the blade (1) is joined to the rotor (2) to a tip (122XY/122YZ). The blade has in a projection on a side/front plane XY/YZ a side/front root portion (11XY/11YZ) extending from the side/front root (111XY/111YZ) to a first intermediate side/front point (112XY/112YZ); a side/front tip portion (12XY/12YZ) extending from a second intermediate side/front point (121XY/121YZ) to the side/front tip (122XY/122YZ). The side root portion (11XY) forms an acute angle ?1 with the axis y in the side root (111XY), 0°??1?10° and the side tip portion (12XY) forms an acute angle ?2 with the axis y in the second intermediate side point (121XY), 0°??2?10°. The front root portion (11YZ) forms an acute angle ?1 with the front pitch axis (1pYZ) in the front root (111YZ), ?10°??1?10° and the front tip portion (12YZ) forms an acute angle ?2 with the front pitch axis (1pYZ) in the second intermediate front point (121YZ), 0°??2?10°.