Gaps in voxels:

[nvidia]

Gaps in voxels:

[revillo]

Have you set your voxel size to be very low by any chance? (Like 0.001 units?) You might have some luck if you set a unit (1.0) voxel size and increase the size of your model proportionally. I think this may have to do with single precision / rounding limitations.

In any case, this problem exists on all hardware I've tested so I don't think it's unique to your card.

[ramakarl]

Confirm that UpdateApron is being called after the voxelization func.

[shincysl]

Same here. Just run the pre-compiled g3DPrint.exe. There are gaps at brick boundaries. UpdateApron is called and apron voxels are updated properly. GTX 850M. All samples are affected by the same issue if you check carefully.

Not sure this is related. In rayDeepBrick(), val.w is initialized to 0. The "skip empty voxels" block will step once anyway because val.w is not checked after transfer(). The check against SCN_MINVAL is put in for-loop condition. So the first non-empty voxel in a brick is always skipped and cause some gaps. But this only affects volume rendering.. It's not related to voxel/surface rendering in the issue..

Additinally, there are gaps at brick boundaries if the voxel size is not uniform (voxelSize.x != voxelSize.y || voxelSize.y != voxelSize.z). In rayDeepBrick(), dir is world space direction but p is index space position. If voxel size is not uniform, dir in world space can't be used to march the ray in index space..

[shincysl]

Additionally, the last step in a brick does not terminate at the brick boundary. In most casts, the last point falls out of a brick. In the neighbor brick, gvdb should add the length from the last brick boundary to the last point. Because the transmittance is always computed using SCN_PSTEP. Actually, the first step in the next neighbor brick is smaller than one step if gvdb doesn't add it..

For better appearance, it would be nice to add some jittering..

[shincysl]

One more thing. the alpha in gvdbRayDeep() is not correct. If the ray hits nothing, the final alpha is 1.0 if background color is 0,0,0,0

[ramakarl]

Check out the latest GVDB Voxels 1.1 release where this should be resolved.