Combining heterogeneous volumes

[FrankEscobar]

I'm trying to combine some different volumes that belong to the same area.

If I use as bounding box the bounding box that covers both volumes the result is ok, but if I sample them separately using each own bounding box the result is not correct.

Obviously I could use the "global" bounding box but I should increase the subdivision amount (lower the voxel size) to keep the same quality.

Is there any way I've missed to combine that both heterogeneous volumes?

Thank you in advance