I know a rather simple question but it’s nothing I’ve done before, I suppose one seam down the pillar will do, treat it like a branch on a tree. The problem is that if the pillar is very long won’t the texture be stretched because there is no possible way for the length of the pillar to fit in the texture space. How would you unwrap it correctly?
The problem isn’t so much the unwrapping as how the texture is mapped. What kind of texture are you considering? If you need to use an image you could scale the entire UV map of the pillar to fit into the texture space, but you might need a high resolution image. Or you could map just a section of the mesh and use a tiled texture that repeats seamlessly. Procedural textures would also work. As you see your approach depends on the look you’re after and how the image will be viewed.