it looks stretched on the model. My question is how to get rid of these stretches or best way to make them reduced.Dont mind the white metal texture its not important the problem is the rusty one.
To correct this you need first a long, non stretched image which will cover the right part of your texture.
Here from left to right :
- Left : more or less the problem you have
- Middle : with a corrected the UV map
- Right : the needed texture with a rusty part all along
The principle is to stretch your UV map part along the texture so that the corresponding parts of the mesh are no more stretched in the 3D view :
The idea beyond that, is to have a proportionality between the mesh shape and the UV shape.
Around this idea, you can setup the different square part of your current UV in several manner :
- Overlay them all (as I did in the gif)
- Or just take each of them and stretch along V the way you whish
But the starting point is the texture : it needs to cover the surface you want and be proportional to the final result.
When you let Blender unwrap by itself, Blender does keep the proportionality. But sometimes, that guides to have too small part so moving the UV manually is needed.
To add to lemon's answer a bit: a common (?) practice is to use a checker-patterned texture image while editing a mesh's UVs to make sure you have even scale and no stretching. The goal is to have the checkers, as they appear on your mesh, be square and to have a checker in one part of the mesh be roughly the same size as one in any other part of the mesh (which indicates that all polys have roughly the same texture resolution). Once you have a nice mapping, you can export your UV map to an image file and use an image editor to create your actual texture, which you would then replace the checker-patterned texture with.
Blender even has options to generate a texture with a checker pattern; in the UV editor: Image > New Image > Generated Type: UV Grid
In your case, though, this mesh is pretty simple, so it might be overkill; but for more complex meshes, it is useful.