UV unwrap and 5-poles - A problem ?

I’m trying to UV unwrap a head. I defined a seam and select all the faces inside the seam but the corresponding UV layout is missing several faces which are mappted to either the whole map or half of it. All the missing (or mismapped) faces are related to some 5-poles in the mesh. How do I correct that? I was working in v2.46 but I tried the same model in v2.45 with the same result. It is a mirrored mesh BTW so only half is mapped.

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I think I figured a few things about that issue.

The first one is that this UV result, that I thought was a sort of default UV calculation/projection is actually not one. Am I correct?

The supporting evidence for that conclusion is that there are no entry in the “UV Calculation” menu that can reproduce that mapping. I can reproject the UV coordinates in different sort of ways but not in that one way. It is sort of a pitty because that would be a good mapping to start with and tweak away but I haven’t found a way to re-snap (so to speak) off vertices to where they should be even if I bring them near the point where they should be. I cannot glue together the vertices. So trying to start with this layout and tweak away is an impossible task because it produces texture overlaps, seams, breaks and that sort of artifacts.

The second thing I figured (at last) is that the “Cylinder From View” and “Sphere from view” are actually using the 0,0,0 point as the pivot for projection. Trying to sphere project a Human face that is located 5 feet above the 0,0,0 point is always going to go wrong. What I tried to do is translate the head down around point 0,0,0, do the UV projection and then translated the head back to its normal location. Is there a way to set a pivot and orient the pivot for the UV projection?

I think it has a lot to do with your layout in general. Usually I just cut the head off the at the neck. What your doing is basically squishing all the face (and in effect the underside of the chin) into a layout with the neck. Where does the underside of the chin go? There are no seams for it to properly lay it out with which is where alot of your issue seems to be. It could be that this “flattened chin area” is just bugging out your UV so that it doesn’t show those verts that should be there.

This is only an idea as I’ve never experienced your issue…but I’ve never tried mapping a head out like that either.

That is an interesting hypothesis but that does not explain the missing faces on the cheek and right above the eye.

How do you proceed when you map a head? What is your technique?

It could very well produce that effect if it is indeed bugging out the UV editor display. However I can’t say thats fact or not as I’ve never tried it.

This is going from memory on a very general head (i never cut em up the same because sometimes I dont like the resulting UV map lol but this is my “general” startign point). First I cut above and across both browlines then I cut down the middle of the top of the head, then I cut down the middle of the back of the head…I follow that along the base of the skull (still in the back), then up around the ear, then down the jawline to underneath the chin area (the one im guessing may be causeing your issue) and then I cut down the middle of that.

It may be hard to understand that…I will google for examples for you.

http://bgdm.katorlegaz.com/lscm_tute/lscm_tute.htm
first google return seems close…they dont go around the ear like I do though. Scroll to the screenshots to see what I’m talking about. Its just a basic UV mapping tutorial for the human head.