Unreal 3 Characters question

fogmann

Hello everyone!

I thought this would be a good place to shoot my question, since I'm sure there's plenty of folks here who could most probably supply an answer, or give some pointers.

So... I'm creating characters that will be used in Unreal 3 engine when it is out. I'm stuck with laying out UVs for symetrical, yet rarely seen character. I understand that low poly mesh needs to have unique UVs if the normal map will be created from high res mesh, since both Max baker and Maya's surface sampler, as well as Epic's distributed computing normal map generation tool have that requirement for successful creation of normal map. But what if I create characters and props that are not major ones, and decide to generate normal map from the texture? Can I still mirror and flip UVs, so that I only texture one arm, hand and leg, or I would still need to lay out UVs for those separately, without any mirroring?

To rephrase the question: will Unreal 3 engine be able to recognize flipped UVs and still render normal map on those correctly? Anyone?

Much thanks!

MoP

I'm pretty sure it'll be capable of that. Most newer engines which support normal-mapping also support mirrored and flipped UVs. Doom3 engine does, so I'd be very surprised if the Unreal 3 engine didn't.

arshlevon

yeah you can even it do it now. doom3 does a great job of mirroring normal maps and the quake4 in game baker does a good job of baking things that will be symetrical. if you want to bake symmetrical normal maps in max select all the parts that are symetrical, then look at the pic below.



in the uv editor click the button by the uvw type in that looks like crosshairs and it will become yellow and the icon will change. next type 1 in the U type in box. thats it. it will move the pieces over one unit in UV space and they will use the same parts of the map as their symetrical brothers, but they will have unique uv space and wont mess up your baking process, and you dont have you cut apart your model. if you engine dosent support this type of mapping(highly unlikley) then just select them after you do your bake and move them back -1 unit in the U direction.

fogmann

Weeee, I even got a mini tutorial, sweet jammies!

Thanks guys, I think I'll be good to go with mirrored UVs; after all, if it turns out they don't render well ingame, I wouldn't expect it to be much work to go back and fix the layout and rearrange the texture, which hopefully won't be necessary.

rawkstar

i think rorschach wrote a sortof little tute on this in the highpoly sci fi beam thingie thread about how mirroring works best in UE3, the 3/4ths mirroring and what not, or however he called it.

cholden

and here's a link to it
http://boards.polycount.net/showflat.php?Cat=0&Number=91531&an=0&page=0#91531