[Topgun]

I need input on wher to put seems on this model. I was never any good at marking seems.




http://www.megaupload.com/?d=M6DITEOX

[Vasudan Admiral]

Break it up into sections that all face the same direction. Something like this:


That's really all there is to it.
The stuff in red you'd separate into easy to manage chunks using seams and project them from above, the green from the side and blue from the front etc.

Remember you can select multiple faces in UV mode and press ctrl+E>mark border seams to specify the chunks quite quickly.

[Water]

Before you do that, it may pay to get used to another Blender tool. Basically it's bug hunting.

In edit mode (and vertex mode) (ctrl-tab switches between vertex - face - edge)

Select > Non-Manifold

Some vertices will now be selected. All vertices through the mirror line can be ignored, it's just letting you know that the mesh ends there, or is not closed.

It's the others that can cause trouble with PCS. The worst ones are the internal faces

[Topgun]

thanks a ton, both of you. but I thought I was supposed to avoid UV projection and use lscm instead?

[Vasudan Admiral]

Use whatever works to best for you unwrap the model in a way that you will be able to texture.

LSCM (now just 'unwrap') projects and unwraps objects for you based on your models seams. In some cases it works great - especially organic shapes, but for shapes that are relatively simple (ie, squarish terran shapes) it's just not really nessecary, and can in fact produce a worse result than regular projections.

Whatever you do though, just don't texture tile.

[Water]

In UV Face mode
And Editing mode (F9)

In the UV Calculation tab
Change from Angle Based to Conformal. Also just recently I have started to unselect Fill Holes.

This will give you excellent LCSM unwrap for retangular objects. The Default Angle Based mode is mainly suitable for organic stuff.

Also in UV Select mode you can Alt+right click to place a seam. Don't get too used to this as it may not be in the next version.

For large or intricate flat selections - Linked flat faces (under select in edit mode) change from 135deg to 179. One you have made the selection, Ctrl-E 0 (Region to loop) then Ctrl-E 1 (mark seams)

As for where to place seams - It depends on the tools you use. If you use  only Photoshop or Gimp, then keep it simple. If you use Blenders Texture paint tool as well then you can do a lot more.

[Topgun]

so, with this new tool, where would I place seems?

[Water]

so, with this new tool, where would I place seems?

There are two main styles of Unwraping
Projected style - where picture of the side of the ship is projected on all polys facing the correct way. (plus top, front etc..) Lots of distortion and limits what you can texture.

LSCM style - minimum distortion, but harder to texture in just Photoshop. 

VA's post about how to break it up is a good place to start.

To see what LSCM will do to the uv map, Try this.
Change to UV Face Select mode

Select all faces, hit u and pick Unwrap (Smart Projections)
Hopefully you have a 2nd window setup to UV/Image Editor. Select all vertices.
UVs > Scripts > Seams from Islands

Have both UV and Image windows viewable. In the UV face select window pick one face. Press Ctrl-L

Have a look in both windows - If you think you could texture that unwrapped shape, you are on your way.

Note: Although it is fast, it will break stuff into too many pieces, and its not very good at laying out the bits for maximum texture usage. (I only use it for testing stuff.)