View Full Version : Strange uv problem

07-10-2003, 12:23 PM
Hi there.
I have recently made the switch from 3dStudio Max to lightwave.
I have some experience of uv texturing and i think i understand the process correctly but i have described it below incase i am doing something gormless.

1. Make a hollow tower object.
2. Make seperate surfaces for inside wall and outside wall.
3. Get texture bitmap (made in photoshop) up in the top left pane.
4. Make uv's for each surface.

The problem is that when i use the cylindrical unwrap on the outer wall surface the far left edge appears slightly outside the image area. When i resize the uv's that edge will not change with the rest of the uv map.
The problem is visible in the perspective window. When i select the surface and move the uv map for it up and down over the image, the texture of the polygon with the edge that wont respond twists as if the texture is locked to that one edge.

Any help on this would be much appreciated.

07-10-2003, 08:52 PM
Sounds like you need to Unweld the object. Unwelding detatches all the polygons from each other and frees up the "locked" UV's. When you're done editing the UVs Merge "m" to re-attatch the polys.

Also, you'll usually want to turn off symmetry when editing UV's as it can occasionally cause some UV movement wierdness.


07-11-2003, 06:51 AM
The problem is that when i use the cylindrical unwrap on the outer wall surface the far left edge appears slightly outside the image area.
Uhm, not sure what you mean, but it happens that the whole mesh is a bit off, e.g. starting at U=0.1 and ends at U=1.1, but it still should wrap perfectly...

And yes, like Terry said, discontinous UVs (i.e. a texture seam, where the texture does not continue from one polygon to the next) are not editable in UV views (unfortunately, Newtek, please change that in LW8, other Progs can do it too...)
That's because those UV-values are per-polygon and the others are per-point, meaning polygons don't have extra UV values for their points unless the texture is dicontinous.
Unwelding points "splits" the mesh, and the per-polygon UVs become regulaer point-UVs and you can edit them. If they don't match again when welding they become per-polygon (=discontinous) again and you can't edit them anymore again until you unweld.

07-11-2003, 03:29 PM
Hi there.
I tried what you chaps suggested. I still have that one stubborn edge of the last polygon sitting there, not moving, while the rest of them move freely.
I fiddled around a bit more and here is what I have found.

When I unweld the four sides around the edge of a cube and make a uv of it the left most of the four polygons is a bit off to the left of the backdrop image in the uv view.
When I look at this polygon closely I see that the far left edge of it seems to have no points. How can this be!!! I ask myself…..
All the other polys have dots at the corners, which I can only assume represent points, while this problem edge of mine is missing the two points that should in- fact define the little sod.

The only way I have been able to texture a simple cube with uv is to add each poly to the map separately and then line them up. This works but would be very time consuming when applied to any half sensible object.

Again, any comments would be much appreciated.

07-11-2003, 04:24 PM
Hm are you sure you unwelded the correct points? :confused:

when you create a cylinder with UVs it looks like on the left side of my attachment (hope it works) and when you select the left most points and press ctrl+u (unweld) the right ones show up.

Thing is one point can belong to many polygons, but in UV view one point does not show up twice (which is somewhat logical, since it can only have on UV actually)

07-11-2003, 05:33 PM
Thank you mate your screen shot just made it all crystal:D

It was all down to one giant misunderstanding.

I was unwelding the whole object and then making the uv map which is why the edge had no points and was not movable:o

I have just mapped a whole model and am very pleased with how lightwave handles texturing.

Thank a lot for all your help chaps.

07-12-2003, 05:23 AM
well usualy unwelding the whole mesh does not harm, but it's perhaps easier to select a bunch of polys you want to map, cut&paste so their borders are not connected to the rest, and after mapping you merge the points so it's a connected mesh again.

btw, Lightwave's "Texture Guide" creates only per polygon UVs so you'll get a UV-view with no points at all, or if it was already mapped it looks ever more weird.
that's why i started writing my own texture guide plugin, see the >thread here< (http://vbulletin.newtek.com/showthread.php?s=&threadid=1272)
It's not perfect, but maybe usefull. (and for some reason Modeler 6.5b crashes pretty frequently while 7.5 and later doesn't, donno if i did something wrong or 6.5 is just that buggy)

Thomas M.
10-14-2004, 10:53 AM
Wasted several hours with this s..t!! I do have several equal looking areas on my model. On the overall object are a lot of detailed weight maps. On one part of this repeating geometry I created a UV map which needed a lot of tweaking around. I now want to transfer this UV map to the other parts of the object. UV copy and paste is the only way I guess. I can't cut and paste the polys as the weight maps would be destroyed. I unweld, copy the activated master UV map, go to the bad looking UV map of the other part, clear the map, paste my master UV and merge the points. My new UV map lacks a lot of points in the UV texture view and is totally ****ed up in terms of the order of the points and polys. It's like the poly have rotated around, even if they look right in the wireframe view, but with the texture applied to it, you can see that the texture is completly garbled.