UV mapping bug

[Kagehi]

Anyone working on trying to figure this one out? I have, recently, tried to do this:

1. Create a wood bridge.
2. Create a texture, for the planks, but with some other bits in the corner of the texture.
3. UVmap the part you walk on (i.e., planks).
3. Apply this texture, so the "planks" sit only on the part of the texture that is for them.

So far so good.

Now:

4. UVmap the uprights.
5. Attempt to apply the same texture to that, then "adjust" the location of the resulting parts, to line up with the width of the plank textures, and other parts to line up with the extra stuff I placed in a corner (like for the rough ends of the exposed uprights).
6. Have to go back and adjust geometry, or even remap the UV, because I missed something.


Now things have gone wrong.

7. Go back into the UV map and find that... instead of the texture I was trying to line everything up with, I get the "default" UVmap, which is produced when you don't have a texture at all, and nothing, including dragging the texture you need back to the selected parts, like you did to apply it in the first place, causes it to reappear.

Needless to say, if you have to completely remap it, you also need to reposition everything to "fit" the texture, which has no become impossible, because you can't see the texture, so you know where to place the things you are trying to adjust, to fit it.

Somewhere in the process, Wings3D will just flat lose track of which texture it needs to be showing in the UV window, when editing the positions, and, there doesn't seem to be anything at all you can do to correct this. After work, I will see if I can find an example file, which has the problem, but, since this is something that goes wrong "in process", simply knowing where in the wings file the error is isn't likely to explain why it gets confused and thinks that it should "display" the default UV, even though the texture itself clearly is using your imported image... It a very annoying bug.

[Kagehi]

Oh.. And, the other hickup... And this one is kind of both a possible issue, and not one: If you map parts of the same object, the "default" behavior, unless you rename the texture, is to always use the texture name for the object (not increment it). It might be useful to have a setting to create a new texture, every time you map another part of the object.

---

Ok.. Means to cause this error, at least in the latest Manifold, which "may" be slightly out of date:

1. Create any object. I used a icosahedron.
2. Select a few faces.
3. Uvmap those.
4. Create a texture from the map.
5. Do not rename the map or texture.
6. Invert the selection, so you now have all other face.
7. Uvmap that.

Now, you have one texture, for two maps, which imho, is useful sometimes, but not always, it might be better, as I said, to "increment" them, so you get a new map, and thus, a new texture.

8. Without doing anything else, ctrl-alt-z to clear the map, since you now plan to redo it.
9. Rename the original texture, and its image. Say: icosahedron2, so your next texture will still be icosahedron1, but it won't be using the same one for both maps.
10. Using the same unmapped faces, which you should still have selected, uvmap again (without closing the uvmap window at any point in the process).

Now you have two textures icosahedron1 and icosahedron2, and... your "image" for the new map will, incorrectly, show the lines from the prior map, your new lines, from the map you just created, and the "default" texture.

11. Attempt to create an image from this map. You are, for some reason, seeing "both" maps at the same time now, even though only one should be visible.. Hmm...

12. Now close the uvmap window. Select *either* of your textures, pick "select" from its drop down menu, then uvmap again.

Uh oh... Where did our texture just go? All that you see is the "default" checker board thing. Selecting, and uvmapping from the other texture.. same result. Wings3D has gotten all confused as to what exactly its supposed to be displaying, as the image, for each of the objects textures. **New** objects don't have the problem. Editing the materials, to see what the results "should" look like, or even importing images, then drag applying them to the textures, then checking them in "Edit material" will confirm that the textures are right, and, obviously, they are also correct in the 3D view. But, the uvmap window has completely lost all track of what texture its should be showing up, when you are adjusting the vertices, edges, faces, etc. of the map itself.

Also.. just to make things more fun, if you select a texture, pick "select" from its menu, to grab all the faces that belong to its map, and then open the UV Editor Window, from the top menu, you don't get the "selected" texture, image, and map. You get ***all of them*** for the object, or.. something else.., like an attempt to map what ever isn't already mapped onto the image? Not sure, but I would expect to get the map(s) for what I have selected, at least, not all of them at once, or some other strange thing, when some of it isn't yet mapped. It, pretty much, makes for a huge mess, and.. if I remember, causes some other hickups as well (perhaps even, under some conditions, the same, 'oops, where did the image go', bug). But, even if not, it doesn't produce behavior that makes sense, if you only have "part" of the object selected.

[Kagehi]

Note - also confirmed in the "stable" official release.