Object partly disappears when zooming out

[plasticbox]

Mesh issue? UV map issue? Texture issue? OSX issue? I have no idea.

I've made two decorative plants that are recycling the pot of the Base Game rubber tree – the mesh is re-shaped and references the original Maxis texture. I must have somehow borked the mesh or the map in the process, and now I can't find what the problem is.

Even when zoomed in close, I can see gaps in the pot of my objects, but when zooming out the issue becomes much more apparent -- the pot basically starts to disappear. I believe this is also the case with the Maxis original but only when zoomed out veeeery far (see screenshots; the last one is 200% enlarged).

I've already remapped (and re-remapped, and re-re-remapped) the *#$§%& pot, but to no avail. Blender thinks the distortion of the map is reeeelatively high, but the original Maxis uvmap is completely nuts and that works fine (see comparison screenshots). Also, the parts with the highest distortion have no problem, the disappearing parts are only on the sides.

Argh. Why does this happen? I'm at my wit's end =(. I've checked for duplicate faces or vertices, gaps, borked normals .. it all looks just fine.


I'm attaching the package below, plus the latest version of the mesh. I'd love to know whether this effect is even visible with other games/machines/graphics cards.

I'm on a MacBookPro with a GeForce 8600M GT (4GB RAM, 2.4GHz dual core etc pp – I run with all graphics options on High and have no other such issues, so I'm sure it's specific to this object). No "Smooth Edges". Maybe this is a graphics problem? Then again, it doesn't happen with any other object as far as I've seen.

Halp would be much appreciated. I'm using Blender 2.46/OSX. I've somewhat come to terms with the insanity that is the Blender interface, but I'm by no means an expert -- could be that I'm not seeing something that should be very, very obvious.


ETA, forgot to mention: I made a recolour of the rubber tree (just a simple hue/saturation change), and it happens with that as well -- one of the pots in the screenshots is using that recolour. Also, the textures are shown below (in the uv maps) with premultiplied alpha -- I'm not using alphaed-out parts.

[~Dee~]

Plasicbox,
I'm sorry I won't be of any help, my meshing skills are still limited.
But I've a question, why would you want to recycle a Maxis pot and texture?
I personally think the Maxis pot is ugly, why not clone your own?
Have you tried with a different object and see if you still have that problem!
By the way...Blender looks totally insane to me. :)

[plasticbox]

Like it says in the OP .. no, I do not have that problem with any other object, Maxis or mine. I've also edited a bunch of other meshes and remapped them (in Blender as well - same version, same install, same machine). It really is specific to this one object.

(Before you ask again, the point here isn't whether or not you like that pot, the point is that it has holes where it shouldn't. And I want to know why.)

[HugeLunatic]

I thought it had to do with the fact that Maxis likes to use solid planes for the backside of meshes, because I am having a similar issue with a window.

Unfortunately it appears to be an OSX issue. It displays fine in Windows with all EPs but as soon as I put it on my PPC iMac (BV) it displays the same issues as yours. Don't know if it is a mesh flaw, DirectX vs. OpenGL issue, or simply that the OSX version is much more picky.

[plasticbox]

With "backside of meshes", you mean the inside of the pot in this case, yes? I have already tried making the mesh single-sided vs. double-sided in Blender (even though I don't really know what that means) and didn't see a difference, but I could try and see what happens if I give the whole thing an *actual* inside (i.e. a duplicate mesh with flipped normals) .. although it would seem kind of strange if that would be necessary, since that would never be visible from the outside. Except through a hole. And none of my other stuff has insides either.

Another idea I had in the meantime: OSX (or at least, my current machine vs. the windows box I had until last year) seems to behave noticeably different when it comes to blurring things at a distance -- on this pic: http://thumbs2.modthesims2.com/img/1/7/8/2/8/2/MTS2_plasticbox_897870_paintings-overview.jpg you can see that the wall becomes noticeably blurry in the background. I don't remember ever having seen that effect on the Windows box (but it's possible that that was just because on that machine, *everything* was blurry to begin with =P!) .. now if it does the same thing with the pot texture, this might *also* affect the alpha, so maybe the alphaed-out parts start to bleed into the texture because they become blurry when you zoom out?

I'm just thinking that maybe, possibly, Maxis deliberately only used that tiny portion of the pot texture .. perhaps that's the reason their UVmap works and mine doesn't. I'll test this soonishly and let you know how it goes .. maybe it's interesting for your windows as well =).


ETA: no, that wasn't it .. with a different uvmap, the pattern of disappearingness changes (like, everything starting to disappear underneath the rim first, not on one edge like before) but it disappears all the same.

[plasticbox]

I seem to have fixed this somehow (phew!) -- not exactly sure what did the trick in the end, either that I remapped it yet again from scratch or that the map is smaller now (and OSX perhaps doesn't like when textures are too stretched), but both pots are working now (they both have the same uv map, mesh is slightly different). There's still a small gap underneath the rim at certain camera angles, but that I've seen in the original Maxis object as well.

Screenshot of the new map below, for reference.

[HugeLunatic]

Glad you got it fixed. It does maybe sound like a small gap caused the issue. OSX does seem to have much tighter tolerances for this game, whereas windows seems to ignore some small issues. Don't know how to explain, but it does make sense texture wise the differences between Directx and OpenGL and how they render.

[plasticbox]

I am completely clueless when it comes to DirectX (it's some magical ingredient that is required for SimPE to work, is the extent of my knowledge =) .. I'm not sure what you mean by "a small gap" -- there is no actual gap in the mesh, and I haven't touched the mesh itself or the texture now, only the uv map. With "gap" I merely meant that underneath the rim, there's still a visual gap sometimes (i.e. the texture disappears) when I zoom around, exactly like the large holes there were before, only much smaller.

Anyhow, I'm happily putting this down to "OSX nitpickyness not being happy with Maxis borkiness" =). Wouldn't be the first time. It's also possible that the first few times the uv map was (partly) backwards somehow and that propagated into every new version -- as far as I recall, the one I have now is the only one that I started completely from scratch.


Thanks for your input! =) Re-re-re-redoing this thing helped me to get the hang of some of the more advanced uv mapping features, so it was good for something in the end.