heyas; okay, one more time about black holes: holes in the mesh that you can see through are reversed normals. they DO render just fine, though. holes in the mesh that you can see through and that DON'T render are.... well, holes in the mesh. missing polygons. (or, n-gons in p3.) BLACK holes are one of two things: 1: degenerate facets. these occur mostly on thin or pointy things, but may also appear for inexplicable reasons on large flat areas. 2: two-sided or polygons sharing the same space in p4. considering the pointy-ness and the general over-smoothing of your wing-like things here; it's my professional opinion that you have degenerate facets. you may need to sub-divide your mesh. if you have sharp edges, you need to bevel them. if that doesn't work, you can try 'fixing' degenerate facets in uvmapper (load the obj and press 'insert'), or split vertices in uvmapper. (note: don't do the latter if you want to morph or bend the object.)