Modular Unwrapping Technique?

ajr2764

Im working on some modular assests that will be brought into UDK and I have a few questions.

Would it be wise to map only 1/4 of that big central platform and just make sure that the ends match up to tile?



Image below is of this outer frame for this lift. The selected area on the left is a glass window(another one on the other side). The selected pieces on the right are glass doors with a metal frame around them. Question is best way to break this down and import into UDK. I was thinking that one mesh would be the frame without the doors or glass windows. The glass window would be the 2nd mesh and the door the 3rd. Could I still have them share the same uv map? Im confused because there needs to be seperate materials for the glass. Ive seen around people having glass on a seperate uv map at a smaller rez..


Images below show the 90 degree platform piece and the 180 piece, I unwrapped the 180 fine and packed it in. The 90 curve peice is unwrapped but as you see in order to keep the same rez as the 180 it needs to be scaled up but then I cant fit it into 0-1. The top and bottom of these pieces have to be unique because the mesh will be instanced to create vertical levels.





Thanks for any info anyone can provide on this.

PhilipK

I would go as far as to have all of those platforms as straight pieces in your unwrap. The inner platform might look a little stretched, so perhaps you may need some bending if you map that separately.

If you can and think it works design-wise I'd split them up into plates in the texture.. That makes sure you can deal with seams extremely easily. And you can also rotate pieces to break up repetition (if your UV shells are straight that is).
Whenever you use plates in your textures, just make sure there is an edge to match the texture seam and you won't have any trouble with distorted lines and such.

ajr2764

Thanks for the reply, I been wondering about objects that are curved like pipes and the above walkway. If I unwrap it straight it would be easier to deal with texture wise, but can the uvs really be adjusted to not stretch and distort? I like the idea of having each of those faces as metal plates in the texture.

PhilipK

Yes, it's as most things a decision you have to make in each case and look at the advantages and disadvantages. But you'll be surprised probably how much you can bend objects while having a straight UV shell.

The closer to the center of a circle the walkway is the more likely you'll get stretching on the inner side, but judging from the screens I believe you'd be able to go with straight UV shells on all those walkways

ajr2764

Ok, I'll do some tests and see if I can get that curved walkway to have straight uv shells with as little streching as possible. Will post back what result I come up with.

Mark Dygert

I see a lot of pieces that can overlap and a lot of unique geometry that could be modular...

ajr2764

OK, so I went back and took the advice I was able to seperate the uv shells for the curved walkway without any distortion. I think now like you was saying phillip that I could do some panels and hide the seam at the edges. I want to paint in some stripe logo that follows the curvature so being that there staright now it should turn out well. Posted some other uvs of the other modular pieces I fixed up. If there is any room for improvement let me know. Thanks.

Mark Dygert

Why not make each panel in the top image a module?

The forked pieces could be straightened with very little stretching, but save a bunch of texture space, you could even weld the seams, reducing the overall vertex count.

Why not stack a lot of UV's on top of each other? You have 3 texture sheets when all of this could fit on one sheet pretty easily.

cholden

This is going in UDK. I'd create tiling textures and a few custom ones using material instance constants. I'd UV these pieces using a multisub so there'd be a tile for the floor, large flat metals, etc and maybe custom light and railing materials.

The reason I'd do this over custom UVing every modular piece is that you will be limited to the largest texture size you have, AND you'll be wasting most of that space by repeating rails and other details over different textures (the same information stored in multiple files). It's just wasteful.

ajr2764

Hmm, interesting suggestions.

@Vig: What did you mean by make each one a module? The forked pieces are the vertical railing supports. Now that i look at it perhaps I could just stitch those seams and get some more space. I do have alot of uvs stacked on top of each other but your saying that all three of those modular pieces could go on one map..like 2048.

@Cholden: I think I get what your saying, I was thinking that having those railing pieces on each map is kindof wasteful. I havent done too much with tiling textures and multisub before but will try to look into it.

By having all the modular pieces on say one 2048 map or 1024 map with a spec and normal map that would be less expensive then each piece with three maps..I hear the less calls to texture maps the better for performance.

Thanks for the useful suggestions.

Minos

I'd go with tiling textures for this. You would save a lot of time on unwrapping and on painting the textures. It will also be easier to tweak the textures later if you need. I find it a pain in the ass to work with unique uv sheets for stuff like this. You might need to change your geometry later and you won't have the flexibility to do so if everything is mapped uniquely.

Tiling textures doesn't mean you need to have thousands of tiny maps. You can always create texture atlases and break your geometry where you need to tile textures.