Why do the textures get so wavy?

[captainj2410]

Alright, i shpered this texture around this model, and it got all wavy toward the center. How can I avoid this? Also, can I change where the TCE identifies the center of the object so I can have the center more toward the back?

http://i11.photobucket.com/albums/a153/captainj2410/blurry.jpg

[Dennis]

This is an unfortunate consequence of spherical mapping. The top and bottom poles on a spherically mapped object end up in a UV space where they're dead in the top/bottom center of the texture, and the connecting vertices can end up half-way across the texture --- essentially, it results in the waviness you are seeing.

The first image I've attached illustrates this. Notice how the top/bottom poles end up sort of in the center of the image. When you look at this in 3d, you get that wavy effect.

In the second attached image, I have 2 spheres, the left one using the original spherical mapping, the right one using spherical mapping.

The default mapping looks clean, but it also slices off 1/2 of each of the top/bottom tiles. You don't have the waviness anymore, but you have seams between each of the bottom surfaces.

Using spherical mapping, you get waviness, but there is only one seam where the textures don't line up. It is quite a big seam, but it's only one.

One thing that some UV mappers do (Ultimate Unwrap and UV Mapper Pro in particular) is "Pole spacing" --- I believe this works by detecting whether a vertex being mapped is in the exact center of the "plan" axis and, if it is, it creates a "teeth" pattern instead of an "umbrella" pattern (see the TCE for what I mean by this --- the default UV mapped sphere has "teeth" on the top and bottom, while the spherical mapped object comes to a point at the top).

This would be nice to have in AC3D, but it's currently not supported. I will look into adding this feature into my UV Map plugin, though, as I've had a use for it myself from time to time...

[Dennis]

BTW --- you may still be getting some waviness for other reasons --- if you don't think the above describes the reason, post back with a side-by-side of the textured image with waviness and a wireframe from the same angle and we can have a look.

[captainj2410]

first pictures: clean shots
second pictures: wireframes
third pictures: overlayed

first set closeup
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing1.jpg
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing2.jpg
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing3.jpg

second set almost full view
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing4.jpg
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing5.jpg
http://i11.photobucket.com/albums/a153/captainj2410/ihatetexturing6.jpg

[Dennis]

Ugh --- what you're running into is a by-product of spherical mapping --- it isn't the one I was describing, but it is one, nonetheless.

Textures seem to get wavy near the poles of a spherical or curved mapping --- I think it has to do with the way the textures are applied to the quads versus how the quads are triangulated when rendered.

The only solutions of which I'm aware is tesselating the surfaces. See the attached image for examples --- in the first sphere, you can see the waviness, but that is almost eliminated by doing a Surface -> Divide.

Of course, the downside is this model just nearly quadrupled in polycount...

HTH

[captainj2410]

you know, at this rate, i think i may just forego the plating texture. i kind of like it without it anyway.

[Dennis]

Sorry to hear that captain --- it does look good both ways - I suppose it depends on what you end up doing with it ultimately render-wise?

BTW, for those interested - I've updated the UV Map plugin to help address the issue detailed in my earlier post with polar coordinates. Grab it here:

http://www.ac3d.org/forum/showthread.php?p=15910

Windows-only at this time.

[captainj2410]

I might not abandon it, i may use that plug in and the randomizer you used in your well project. Whatever, i've got a few days to think about it until the contest is over this week.

[Dennis]

One thing I would try also is cutting down on the length of those panels by slicing through them. See the attached image for what I mean --- basically, slice the surfaces where the red lines are.

The Divide Loop tool *should* handle this nicely ( http://supercoldmilk.com/ac3dplug/divloop.html ). Hopefully, you're on Windows and can utilize it.

I think that if you do this, it will cut down on the waviness, if not all but eliminating it?

[captainj2410]

Well, I tried that divide loop tool once i did the uv spherical map. Here's what it looked like before:

http://i11.photobucket.com/albums/a153/captainj2410/before.png

Here's what it looks like now:

http://i11.photobucket.com/albums/a153/captainj2410/after.png

I may just give up and do this!

http://i11.photobucket.com/albums/a153/captainj2410/maybethisllwork.png

[captainj2410]

There was definitely a visible improvement, but I don't think i'd like to divide any more loops than I already have. The model is complicated enough for my computer!

[abir784951623]

I don't know!

[nightoftheroundtable]

How can a model get to complexed for a computer?