Using non-square textures (2048x1024 etc.) in Maya/Unreal

Shyralon

Heyho
I got a task where I have to use a non-uniform texture (2048x1024) and bringt it to Unreal.
Unfortunately there is not too much documentation about that, so I pulled out the good old cube for testing:
Here's my UVlayout (using the -1 to 1 space, so it's double in width), and below my beautiful testing texture.
Unfortunately it is not displayed correctly in both maya and unreal, it's somehow stretched.


And here is how it looks when applied (looks both the same in Maya/Unreal):


Could someone explain me how to use non-square textures right? Would really help me a lot.
On a side note, what's the advantage of nonsquare textures compared to the standard ones?
Thanks a lot

Scruples

The advantage is for long slender objects that need to have a texture with less UV seams it's easier to pack them into a rectangular space instead of square, weapons typically fit into that category.
In Maya, in the Uv Texture editor under 'Image' enable 'Display Image' and 'Use Image Ratio'.
edit: faces tend to be 2:1 ratio too since the cylindrical-ish unwrap tends to make them fairly rectangular.

m4dcow

Well, you should be using 0-1 in U and V whether the texture is stretched or not (not -1 to 1 U). I think maya has some option in the UV editor for non square textures, but must be applied to the material. Personally I layout my UVs in U 0-0.5 and V 0-1 or the other way around depending on whether it is a vertical or horizontal non uniform texture. Then, you can either stretch it out the full 0-1 in both U and V (best to do it precisely with a script). Or you can change the tiling in the place texture 2d node in maya which you have to do for all you maps, or build in a parameter into your material in UE4 which will control your tiling.

m4dcow

If you do "image-display image", and change options in "image-image range" you can see what is going on better. Also, "image-use image ratio" is what I was talking about above, but its sort of weird to use so I don't.

Raane

I dunno if it's changed in the latest versions but i found it much easier to work square and then cut it down and scale the uvs after. All your translations were warped out by the image ratio.

Shyralon

The Display-image-ratio thing seems to work fine, I will go with that for now.
If there are any more problems concerning this I will post here again.
Thanks for all your help

Deadly Nightshade

I just unwrap everything to two 1.0 squares, set a fixed pixel distance for the shell spacing (usually 8px, but depends on many factors). Then when I'm done I scale everything down to fit the default range. Then just set your dimensions under the Snapshot options and render out the UV map.