Apparatus and method for approximate trilinear interpolation for scene reconstruction

A non-transitory machine-readable medium having program code stored thereon which, when executed by a machine, causes the machine to perform:

• dividing a three-dimensional (3D) space into a voxel grid comprising a plurality of voxels;
• associating a plurality of distance values with the plurality of voxels, each distance value based on a distance to a boundary of an object;
• selecting a first interpolation mode for stepping a ray through a first one or more voxels of the 3D space responsive to the first one or more voxels having distance values greater than a threshold, wherein stepping the ray through the first one or more voxels in the first interpolation mode comprises performing interpolation of the ray through the first one or more voxels by passing distance values associated with the first one or more voxels through a sign-preserving shift circuit, the sign-preserving shift circuit performing bit shifting on the distance values, wherein a number of bits in the bit shifting performed on a distance value of the distance values corresponding to a voxel of the first one or more voxels is selected based on a plurality of voxel address fractions of the voxel;
• detecting the ray reaching a second one or more voxels having distance values less than the threshold;
• and
• responsively selecting a second interpolation mode that is more precise than the first interpolation mode for stepping the ray through the second one or more voxels.