Method for adding geometry without losing work on UV map?

[virtualalias]

I've got some additional space on my UVW map that I'd like to use with more detailed additional geometry. I've already unwrapped the entire model and I'd very much like to avoid having to re-do it.

My changes will not be affecting most of the existing geometry, so is there a way for me to keep what will still work and remove what won't, then add the geometry and unwrap just that bit?

Maybe there's a better way to do this, like creating the additional geometry, unwrapping it and then compiling the two together?

I don't care how it's done, as long as I get all of it onto one map. Any suggestions?

[Cryrid]

Which program are you using?
I know in XSI there are a few ways to do it, and I assume the same goes to other programs. Usually I just select a face, extract it, do whatever needs to be modeled/unwrapped on the new mesh, and then merge it back with the original mesh (and hit the merge UV button).

[virtualalias]

I am using 3dsMax. I suppose it's the act of merging it back that I'm having issues with. Every time I go back to 'Editable Poly' in my stack, it destroys everything I've done in Unwrap UVW.

As you can imagine, it's a pretty obscure thing to find a tutorial for.

[Tom]

Fortunatly you have us to answer it

you can collapse the stack - then modify your geometry (attach, model - you name it). then add the UVW modifier again and the new geometry is added. Some bits may be distorted as you have used those polygons to create new (eg. extrusions).

Another way to add more geometry to the same texture space without collapsing the stack is to do it like this:

render your UV coordinates for your one piece of geometry and use it in the UVW modifier as a background as you see here... and finally gather all the UV maps up in photoshop.

Its a bit more complicated, but you keep your pivots and modifiers on all objects involved.



Those are the two methods I use. mostly the first unless I have modifiers I dont want to lose.

[virtualalias]

Thanks a ton, bro. That helps a lot. I haven't tried it quite yet, but I will and your instructions make perfect sense.

[swag]

You can also use the "preserve UV" checkbox in the Edit Poly modifier. But this is somewhat limited as most of the time it doesn't work. But if you are just moving verticies on a plane, it is perfect.

But as Tom said, just collapse the stack and then add the UV modifier again. I usually do this when there is too much geometry and I need to hide some of it (it's annoying that you can't do that directly in the UV modifier).

[virtualalias]

I'm not sure if this is a connected issue, but I did as Tom suggested and I doubt that it is a coincidence that I am having a bit of deformation in the area I went back in and worked on.

It did deform, like Tom said it might, but I straightened the vertices/faces in the UVW Unwrap Edit window.

This is what happened:


There is a lot about my texturing that could use some improvement, as it is my 2nd model/texture ever made, but the deformation is the only thing that I can't understand and therefore correct moving forward.

I will attach the map with UVW template over the diffuse, in case that helps. Perhaps I need to get in and see what my edges are doing? Maybe turn some of them? I really don't have any idea.

Edit: Screen-cap taken using Doylle's viewport shader.

[Tom]

its probably because you moved or welded a vertex that was a part of the "wall". and now that coordinate has been deformed. What you need to do is re-UV map that polygon. as far as I know there are very little solutions to this other than taking precautions or removing edges, then vertices (that way you might not screw up the UV coordinates instead of welding)

so ye, you need to re-UV it. but since its a plane it shouldnt be that big a deal

Its a very common "problem" when you go back and alter the geometry. (each vertex has a UV coordinate as well, and if you modify the vertices - then it has effect on the UV map..)

[sampson]

with preserve uv's on you can make cuts and extrude in/out (but the edges on the side will be deformed) welding is a no. it doesnt look like the most complicated model though so it shuldnt be too hard to re uv

[virtualalias]

Thanks guys. I guess I was dragging vertices around willy nilly, figuring it was like working with a vector-based custom shape in photoshop.

I'll try re-doing that area and see what happens. Thanks again.