Help with uv mapping

Well im creating sort of a 3d steam truck. And there is one cilinder i have, its a bit deformed, but i wan tto put a material from an image onto it. I fallowed tutorials online, and the only result i got i will add in the pictures, then i found out its bad uv mapping, i tryed everything from all the selections that uv mapping gives when pressing u, still coudnt produce a good result. I have no clue what to do next. These are my problems:

Did you select all faces, unwrap and select smart uv project?
Depends how you want it. Did you mark seams? Looks like decent quads. To keep it simple I would mark a seam at the end caps and a seam to cut the cylinder in half. Select all faces and unwrap.

It’s never a bad idea to apply scale before unwrapping.
In object mode. Select. CTRL + A > Scale. Then unwrap again.

But you’ll still need to add seams or sharps if you aren’t using smart uv project unwrap. Edit mode. Select edges and CTRL + E > Mark seam. Keeping adding seams and unwrap a new until it cleans up.

Model looks nice.

So in order for it to work normally first i need to unwrap and then use smart uv project? Okay thanks for the tip i will try to do that. And I tryed marking scenes but didnt result in any good way but i will submit more pictures

Exactly. Think of your model being made out of paper and you want to lay it out flat on a table. If you don’t cut the paper model in certain areas, you will have to squish it to lay it flat. And that’s exactly what is happening with your UVs in Blender if you don’t add seams. So, where would you have to cut your model if you wanted it to lay out flat?

I have puted ą seam on the caps and tryed cutting it in half then in half again. This is the result i came up, althought the caps themselves look ok, and one of the parts as you can see is still off im afraid of adding more seams it might ruin it ?


I tend to go with the motto: As many seams as needed, as few as possible. So I guess I would make a seam around each of the two end caps and one along the side, but not crossing into the end caps ( just as Freezeframe already suggested): This will keep the end caps intact in their circular shape and will offer a cleaner unwrap of the cylindrical part.

And no, you can not destroy anything by making too many seams: If the unwrap doesn’t look good, just clear the seams and start anew.

This is my result on a similar mesh (the seam along the side is normally on the bottom of the mesh, of course):

I first do a U > Unwrap of the whole mesh, then I select only the cylindrical side part and unwrap again with U > Follow Active Quads, which will give an almost distortion free unwrap.

If you have any geometry protruting from that cylindrical surface, I would unwrap that separately to avoid confusing Blender. Hope that helps!

Well ihave tryed your way, the result is better for the cylinder part but now the caps look way off, and im not sure but i still dont get the same result as you in the uv window, the parts all way off maybe becouse i have a lot of extruded parts over there, anyway im going to add you the blender file maybe you could take a quick look?

There were a few issues with your mesh:

non-uniform scaling - I assume after transforms in Object mode (hit Ctrl-A > Scale to fix that)

Overlapping geometry - W > Remove Doubles deleted over 500 vertices from bad geometry on that mesh

I added an Edge Split modifier to take care of the mesh smoothing.

Here is the altered file for download: .blend as .zip

Hey i have another question for you, now that i sorted the whole uv map thing, i started adding materials. So i applyed it to the main cylinder all is fine, but i also want to add some rust and only in certain areas, i have a texture of that, but applying it to the face only makes it look bad and square logical thought, but i tryed painting over it with the texture paint, it looks quite ok as much as i want it, but when i go to rendering it doesnt even show up. What have i missed?