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gizmo1990
01-07-2004, 12:48 PM
Ok I feel like a complete dunce but I just can't get my head around UV mapping :( :(

I've read all the big tutorials on it and the manual but it just seems like theres millions of questions running around my head that neither answer!

2 examples spring to mind.

Why, when I create cylindrical UV coordinates for my head model, are they ordered front of face on the left and back of face on right? I've always created my head textures with the face centrally placed so that the seam runs along the back of the skull. There seem to be no controls that allow me to pick the 'rotation' of the coordinates so I can replicate this??

Another is why can I 'move' mapping coordinates completely around on some models (ie select them all and move them about the viewport) but on others their tops and sides stay rooted to where they are and only the insides move? This seems to happen on some models but not on others?? What is the reason for this??

I hope someone can help me out with this as its really fraustrating! :( :cry:

Jim.

leigh
01-07-2004, 02:10 PM
Calm down my friend :)

Let me answer your questions.


Why, when I create cylindrical UV coordinates for my head model, are they ordered front of face on the left and back of face on right? I've always created my head textures with the face centrally placed so that the seam runs along the back of the skull. There seem to be no controls that allow me to pick the 'rotation' of the coordinates so I can replicate this??


If you rotate the model before unwrapping it, your seam will be placed correctly initially. However, there is nothing stopping you from placing the seam wherever you want once you have unwrapped the model. Simply select your model, hit "y" and then hit "n" to bring up the Rotation tools numeric panel.

Rotate it -90 on the Y-axis (if it is facing forwards on the Z-axis). Unwrap. Rotate the model 90 on the Y-axis to reset it back to its original position.


Another is why can I 'move' mapping coordinates completely around on some models (ie select them all and move them about the viewport) but on others their tops and sides stay rooted to where they are and only the insides move? This seems to happen on some models but not on others?? What is the reason for this??


This is because LightWave's UVs are discontinuous. In order to move them around, you need to use the Unweld ("u") command before editing your model. Just remember to Merge ("m") them again when you're done :)

gizmo1990
01-07-2004, 03:56 PM
Aha.. thank you Leigh! :applause:

I have another more broader mapping question...

I'm texturing a human bust, head and shoulders and I can't figure out the best way to achieve this? I

started texturing the head first with a cylindrical map. Im now thinking about the rest of the neck and shoulders but how would I do this and not get a seam where the texture maps meet up (around the neck area). Im thinking its going to be very difficult to get them to meet up 'exactly'??

Am I going about this all the wrong way though? Is there some other method I should be using? The trouble is I've already done my head maps and Im worried Im going down the wrong route??

Any help appreciated!

leigh
01-07-2004, 09:32 PM
I did some texturing for a character recently that had totally seperate UV maps and textures applied to the head and shoulder/chest areas. All I did to hide the transition between the two areas was simply to paint my textures very carefully.

I made sure that the colour textures had the same tones around their edges, and that all the other textures used the same values of gray around the edges where they met. Simple as that :)

gizmo1990
01-08-2004, 06:18 PM
Thanks a lot Leigh, Im on it now! :thumbsup:

Jim.

Carm3D
01-08-2004, 06:43 PM
It is also possible to make two UV maps and have one overlap the other. You can paint an alpha map for the second layer and have it fade out to hide where one ends and the other begins.

There is one catch with this, however..

Anytime you layer UV Maps on the same surface you will get the "UV Zipper" effect unless you follow a few simple steps to avoid it.

After you have your head UVs done (assuming the head will be on top of the neck/shoulders UV), do these steps:

1. in your UV Texture window, select all polys in the map.

2. Hit the - key to hide them.

3. In perspective view it will look like the head is missing. Pick all polygons that touch the hole in your neck. Including polys that touch it with only one point. These are all the polys that would get the zipper artifacting if we didn't fix it.

4. Use the Texture Guide tool.. place it anywhere in a viewport, hit n and tell it to add to your existing UV Map for the head.

5. with these new polys added to your UV Map, you'll need to do an UnWeld at this point.. You shouldn't have to, but you do.

6. Select the polygons again, hit = to hide everything but those polys.

7. select the points of these polys and use "Set Map Value" to place all the points at 0, 0. This will place them in the lower-left corner. Your alpha image for the head better be black in this corner.. If not, place them at 100, 0 (lower right corner), or somewhere else where the alpha is all black.

8. Hit \ to unhide, m to merge everything back up and you're good to go.

OKay maybe it was more than a few simple steps... but after you do it a few times, it seems simple. :)

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