UV Smeared: What gives?

Well it doesn’t get too much simpler than this… Things turned to custard after the 2.7 release, but I don’t know if that’s relevant.

This is a Blender Internal render. I have a cylindrical hoop I want to map a cylindrical UV to. I mark a seam, then split the screen to hold both the 3D view and UV Image screen.

I create an image 20000 x 256 pixels: I have a JPG that big that I want to map exactly to the UV Map.

The default UV Map comes out very square, like 1024 x 1024 square, so I stretch it out to fit my 20000 x 256 image.

Once done, I create a Material, open a texture for the material, and load the image.

No tweaks, just a quick check that the Mapping is “UV” and “Flat”.

On rendering, the image is smeared.


What have I overlooked?

Ridunkulously simple Blender file here.
Blender 2.72b, Mac OS 10.6.8

You didn’t pack the texture file into your .blend - which is a bit unfortunate considering we’re talking about texture mapping issues. However, this is what I get with a UV grid (image texture) and a UV layout similar to yours:


Looks all right?

GDI I’m always forgetting that :frowning:

Sorry Ikari: the file’s packed in now, same link.

EDIT: I… don’t think that looks right. Doesn’t the UV Map (orange grid) have to be within the Image boundary? Where does the image information come from for all the UV points outside of your image???

My UV grid image is seamless and tileable, so I just let Blender tile and repeat the image ad infinitum for the parts of the UV map that exceed the image borders…:smiley:

Concerning your problem: I think Blender has problems filtering an image with a so unproportional width to height ratio. Playing around with the filter settings improves the results drastically:


I’m not a Blender Internal expert, though, so perhaps there are other things to optimize…

Hey, thanks Ikari, that’s put me on the right path :slight_smile:

The weird thing was that Blender 2.69 (and earlier) was fine with mapping the wide, narrow JPEG I have as a texture map. I realise it’s a really unusual ratio, but I needed a hi-res image mapped to a long, thin rectangle. I guess I could cut the mesh image into several smaller rectangles and stack them into a square shape, but this starts getting difficult to manage in terms of removing visible seam artifacts.

Can you recommend a method of creating and mapping long strip images that tend to have continuous, unbroken artwork?

Thanks for your help!

I can not see any distortions with unwrap as it is in your file (see texture settings). Sorry for tube around and red sun…
Where from is Blender version you use now?
http://www.pasteall.org/pic/show.php?id=79267
Edit: full view, no doodles :wink:

Thanks Eppo. I think Blender might’ve used a different default filter prior to 2.69, or there’s something new with the treatment of non-square images I’m not familiar with.

But I have it corrected now :slight_smile:

As I said in the first post I’m currently using Blender 2.72b.