View Full Version : UV Map Size Question
11-09-2007, 09:30 PM
I LSCM unwrapped my object in Bodypaint and then I rotated the UV map to the angle I wanted it. I then noticed a lot of wasted space on the top and bottom of the UV map so I was wondering if I could create a UV map was not square, let's say a rectangle shape, to prevent all of the wasted space above and below on the UV map? or should UV maps always be square?
Is it as easy as typing in a non square value into the texture size settings, and will this create any stretching or other problems as a result?
Sorry if this is a stupid question.
11-09-2007, 09:46 PM
It kinda depends on how you plan to paint on the map.
Ideally, the dimension of a face in your uvwmap should be the same dimensions as the face. This can lead to some instances where you get wasted space in your map (if your map is square). If you stretch the uvs to fully fit the square space, you'll get no wasted space, but there are a few consequences.
1) if you paint say a circle on your map in photoshop, then bring it back into 3d, your circle will now be an oval.
2) If you paint a circle in bodypaint (or you're making a displacement map in zbrush or mudbox), it should automatically create an oval in your 2d map, so that the result is circular in 3d. However, if you now ever need to go back and edit the map in 2d in photoshop, you'll have an oval shape to modify instead of a nice circle.
And 3) Because you now have more texture resolution going in a single direction, you can get weird artifacting where if you zoom in close to your character, you'll see more resolution going in one direction, and not the other.
If you're painting something very simple, like I'm painting a flat plane that's 4 times longer than it is wide, then I'd just apply uvs to the object so that the uvs are square, then I'd make a canvas in photoshop that's 4 times wider than tall, and paint 1 to 1.
But if you're doing a character, I'd probably try and keep the ratio of uvspace to face space the same, and just accept the wasted space. It will mean less brain contortions, which is always good, even if you sacrifice a little texture memory.
11-09-2007, 11:50 PM
Yup I created a 2048 x 1024 texture and it distorts the UV's. I thought I could create the horizontal background shape and then unwrap the UV's normally but no go. :)
11-10-2007, 03:12 AM
You can increase the scale of UV maps to get the best use of space, just keep the proportions as close to original to avoid stretching. I've been mapping a steam train for the past four days; to get better quality I scale up some parts (like window frames) and scale down others that won't be as visible.
11-10-2007, 03:38 PM
Thanks Greg! :)
11-10-2007, 03:38 PM
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