Hey guys, I continue to work on the 3D thing, and I have a few questions, it would be *super helpful *if you can answer me, even for some of my questions. So if you even have a hint I would like to hear about it. Thats what I have now: ART example <https://sketchfab.com/models/d267102434274bdbb5f75f5b9ef27b44>, so with some help I might succeed. Thanx, Tomer 0. What is the main reason that _extract_isocontours_from_grid doesn't work on ART? is it just not implemented? is there another big problem beneath it? is it related to KDTree? How come ENZO work and ART doesn't? 1. What is the ghost zones idea? does it work on ENZO? does it work on ART OcTree data? 2. Can ghost_zone_interpolate work on OcTree? on OctreeSubsetBlockSlice? 3. In get_vertex_centered_data, it gets from ENZO 6X6X6 data blocks, is it true that one of the differences between ENZO and ART, is that the adaptive mesh of Art is divided to 2X2X2 but ENZO has 6X6X6? The code I look at is in "construction_data_containers.py" YTSurfaceBase.get_data(..) function line 1031: for block, mask in self.data_source.blocks: 4. What is main idea of the classes AMRGridPatch(YTSelectionContainer), OctreeSubsetBlockSlice(object), OctreeSubset(YTSelectionContainer)? what is the difference between them? doesn't OctreeSubsetBlockSlice supposed to inherite OctreeSubset? while calling self.data_source.blocks for ENZO I get AMRGridPatch and for ART I get OctreeSubsetBlockSlice. but AMRGridPatch inherits from YTSelectionContainer as OctreeSubset. different to OctreeSubsetBlockSlice which inherits from object... The code I look at is in "construction_data_containers.py" YTSurfaceBase.get_data(..) function line 1031: for block, mask in self.data_source.blocks: