I am having trouble/questions learning UV mapping. I’ve read through many tutorials and watched several youtube videos and have found many great pointers already!
However, I have come across these two problems I can’t find solutions for:
Firstly, is this the proper way to unwrap a bell? (I plan on texturing the object using photographs of an actual bell, and would like it to be seamless. For the top, I plan on using the “Polar to Rectangular” filter in Photoshop, and so this may work OK. All the guides out there say to mark a seam and separate the tops of the “cylinder”, though.)
On the right side of the UV image there are several faces that are out of place. Is there a way to move these back to the left hand side of the checkerboard image? (I unwrapped the bell from a front-side-view and used “Cylinder from View” as my calculation.)
I attached a jpg and a blend file so you can see closer what I’m trying to describe. Thanks so much for any advice!
By far the best way to texture something (IMHO) is to use Projection Painting.
Basically, I would unwrap the object any-old-way (but put a seam or two in there so that there’s some sense to it, in the case of a bell). That mapping becomes the “destination” mapping for your bell.
One or more source-images from real objects become the source bitmaps for your painting work.
What projection painting then allows you to do is to “paint right onto the surface” of your bell.
One thing that I haven’t experimented with directly, but plan to, is the notion of using Camera Mapping as a source of source-bitmap data for this purpose. (Right now I have no idea if|how-well this would actually work, and I’d love for anyone out there to chime-in on that.)
(And by all means, if anyone else wants to say, “no, no, sundialsvc4’s full-o-beans, a better way is this…” believe me, I’m “listening to” this thread too.)
one thing i wonder here
how did you get the faces number in the picture?
you could also simply unwrap in 2 parts 180 degrees with one seam,
and then have only one picture of half the bell as long as the seam is not too bad
but also depends on the angle of view !
@sundialsvc4:
Thanks for the suggestion. Perhaps using this method will help to understand the UV map better. Sounds like a great new learning opportunity, too!
@RickyBlender:
The faces numbers are built into the texture checkerboard I created (actually recreated from a reference online). Hmm, I wonder if the texture wasn’t included in the blend, appologies if it wasn’t. I attached the JPG 1024x1024px (my version is 2048x2048px but is too large to post here) instead. Your advice is good, however, I need both halves of the bell to be unique (ie fully textured around the bell.) This is because it is the Liberty Bell and there is a crack only on one half of it!!
I attached an even closer close-up to this thread. It shows the UV window and a descriptive arrow about my 2nd question above, as to why the two faces are on this side of the UV unwrap instead of the other side. Is there anyway to “move” them and weld them manually over to the other side?
>Is there anyway to “move” them and weld them manually over to the other side?
There must be some problem with your mesh location in space. You don’t need all that mesh. I made simple mesh pattern and it unwraps fine. Except for the top; those meshes end up as a point you know. So you get flat triangles for UV. I added Subsurf modifier that made the final bell shape smooth. You don’t need all that mesh.
I’m thinking this geometry is not going to be the best. All those triangles on the top don’t unfold how I would like them to. It would be ideal if the checkerboard continued through those tris… Maybe there is a better way to make the shape?
I’ll keep working at it! Much appreciated your response is, ridix! I simplified the bell shape, rotated it 90° (around z), and this fixed those hanging UV faces.
I’ve recently been working on other projects, but would really like to finish this bell. It’s very difficult to understand UV unwrapping even after reading lots about it. Can someone tell me if this is the right way to unwrap this object?
Thanks in advance. Essentially I am going to paint photographs over the UVs. You can see in the attached image an example of the images I will be using. Basically all the images are from different perspectives of the bell (the Liberty Bell, for those who are wondering!)
It seems there will be geometry on the top of the bell that will maybe be hidden so it could be that the first unwrap i had was correct. I was just unhappy with the way the triangles at the top unwrapped so strangely.
Consider this: the bell is cylindrical. The reference images that you have are flat. Specifically, each of them is the projection of the imagery that’s on the circular surface of the bell onto a flat image plane within the camera, wherever it was.
The proper technique to use here is … to reverse that process. You want to project the imagery from each reference photo onto the surface of the bell model, from a plane that corresponds to the film, using a lens-setting that roughly corresponds to the one that was used to take the reference image.
Look therefore at the “UV Project Modifier,” here.
Now, this is no panacea. There’s lots of detail available where the bell is more-or-less parallel to the film plane, but it dwindles to zero as the surface of the bell rotates away from the image plane (i.e. the sides).
Honestly, I think that you might to better here with “real modeling.” In other words, you actually model the surface of the bell (with or without the crack), and you wrap text around it and then extrude that text, and you add bumps and scratches and other surface irregularities. You ought to come up with a pretty darned good bell that can be viewed from any angle.
Also… don’t forget to look on free-3D-model sites. The Liberty Bell is probably out there now in some importable format.
Sorry for the, uhhh,triple post there. (Can one of the moderator team kindly clean that up for me?)
The more I think about this, the more convinced I am that the only way you’re going to be able to texture this bell effectively is to model it, and texture it (using conventional materials and textures … that is to say, texture and material nodes). You’ve got existing speculars and other problems in your images that you can just never get right.
So, you might want to use the “slide projector” trick strictly as a source of on-the-object reference imagery. Then start assembling the bands (a bump map, perhaps), create a text-object, wrap it around into a circle using the “warp” tool, extrude it. Carefully knife-cut the crack, extrude the edge inwards, bevel the heck out of the join. The color and the battered surface (this poorly-made bell has led an interesting life…) is pretty straightforward texturing. Discard (that is, disable…) the reference image-texture.
Despite the apparent surface roughness, this can be a fairly “low-poly” model, except that the faces along the immediate path of the crack will need to be subdivided. (Work inwards toward the chosen location of the crack, subdividing most finely only adjacent to where the crack will be.)
The rough bottom of the bell (obviously it has been dropped many times) can be an Alpha-zero ring with a bump-map texture (not just normals) applied to it, especially if the bell is not going to be viewed from every angle.
