Tiling Textures/UVs for game environments

Wocky

Hi there, I was wondering if someone might be able to help me.

I'm experimenting with environment modelling for games. I have heard that environments are textured using 'tiling uvs/textures', rather than unique unwraps.

It's not something I've done before, and it seems I'm missing something in my methods: despite the fact that my texture tiles fine, it does not tile properly when applied to a curved object.

Below I have linked an image showing the problem; once a chamfer has been applied, seams show up in full force. I am using 3Ds Max 2011, and I have tried using the 'UVW Mapping' modifier (currently on Box mode), but I cannot remove the problem. I haven't had any great results Googling my issue, sadly.

Image: http://img251.imageshack.us/i/picxv.png/


Is there any special method that needs to be gone through in order to remove these troublesome seams? Or is this perhaps a limitation of not using unique UVs? It makes me wonder if I have completely misunderstood something.


Sorry for the newbie question, I appreciate any advice you guys can give me.

16bit

You probably chamfered after you set the uv's or its the default uv's. You'll need to uv it after you have finished modeling it.

Wocky

Thanks for your feedback, 16bit.

However I was under the impression that I wasn't supposed to unwrap the environment, at least not in the same way as one would unwrap a character. Is this something I've misunderstood entirely?

16bit

you have a couple of options. You can unwrap it like you would a character. This would help with the chamfered edge and allows you to hide your seams where you want. Or you could just add a uvw map modifier with a box map, this is easier, but can make stretching easier to notice.

I would personally just uv unwrap it.

MeintevdS

I'm afraid so. An unwrap is just a way to tell your program to display what pixels on what part of your model. So if the seams don't align on the uv then that means the texture will no align on the model and thus show you an ugly seam.

What a seamless or tiling texture lets you do is that it allows you to overlap geometry and that it allows you to place it wherever on the uv field.
This works perfect for stuff like walls such. It also allows you to, for example, increase the amount of bricks you have in your walls by increasing the amount of tiling. This way you could texture all the walls in your scene with a 256x256 texture without seeing pixels when you get near your objects. (<not saying that's advisable, but it's possible )

In short, no (or at least very few) texture(s) will give a good result without any unwrapping done. If you don't want any seams you'll have to make sure they line up in your unwrap. Tiling textures let you cheat to a certain extent but it's no wildcard to be lazy

I hope this made it a bit more clear for you. I'm not that good at explaining stuff and I'm no expert on it myself, but this is how I always understood it.

16bit

Agreed. Tileable textures will always have seams unless it's for terrain or something similar. Unwrapping will just allow you the ability to decide where you want the seams at.

Anuxinamoon

As for the no uv's idea, you are probably thinking of a shader that uses Worldspace Co-Ords to apply a tiling texture to your model. It projects the UV co-ord's real time from X Y and Z to apply the texture to the model. The benefits are obviously no unwraps and the ability to set a different texture to be projected from a specified Co-Ord.
So you can make one for rocks in a winter area which places a snow texture on the Y and rock on the XZ, so whenever or however we rotate the model in the game, the snow will always fall on the top of the rock.

The downsides to this is of course, little control over the uniqueness of the model. Also you need to add more polygons via bevels to smooth out any angles that are less than 90, as severe stretching can occur.

Tiling without worldspace requires UV unwrapping as mentioned above

jimmypopali

I would either unwrap it like normal, or at least use the tileable texture and box map it. But I'm thinking that the seams will show on at least one side...

Lennyagony

Your almost on the right track with this, many larger assets do use tiling textures and the UV's are, in most cases layed out differently than say a characters.

You will still need to lay out UV's, however you move them outside the 0-1 UV area in your unwrap and if your not worried about being a bit sloppy different parts of your assets UV's can overlap on the same space.



Often you end up with seams, which depending on the asset isn't a big deal. If its a blatantly noticeable seam place a pretty prop with unique UV's on top, use a tiling trim texture that also tiles with your main tiling texture or if your engine supports it blend between different textures to mask the issue.

Wocky

Wow, thanks for all the advice guys! I understand much better, somehow I'd gotten it into my head that I wasn't supposed to unwrap at all, haha. Makes alot more sense now. I have unwrapped my objects as suggested, and it looks much better now.



Thanks again!

Incidentally, has anyone had this odd transparency problem (as you can see with the chain links) in Max? I'm still using Xoliul's shader here, and transparent objects won't display properly if placed behind another transparent object. It's been bugging me for a while.

nicafornica

nice wheel cart or cart wheel