Blender UV

i'm not sure what you call it, but does anyone know if you can do mirrored UVs in blender? (so you only have to use one UV group to represent two sides of a symmetrical object) i've looked around myself can't seem to find anything.

 

I'm not 100% sure I'm following you, but I have a fair bit of experience with Blender so hopefully this will answer your question.

If you want to project the same image on both sides of a symetrical object (not mirrored) then in Blender you go to "uv face select" and select all the poly's in your object, then go to "top view" (num pad 7), then in the "UV Calculation" panel select "Bounds" and "From Windows". This will apply the UV map and top and bottom will be identical. Basically, your whole model will be mapped from the top view.

If you want to do top and bottom in a "mirrored" uv's (like you want to map the top and bottom of a hand separately), you'll have to do it in two steps:
1. In "uv face select" select all the faces of the top of the hand, then go to "top" view, then in the "UV Calculation" panel select "Bounds", "1/2" and "From Window". This will give you a flat projection of just the top of the hand. Select and move your UV's to the side of the window in the "UV/Image Editor" window.
2. Then repeat the process for the bottom of the hand, except make sure you have a "bottom" view of the hand before doing your calculation.

When you're done with step 2, move the uv poly's around until you have them the way you want (side by side or one on top of the other) in the "UV/Image Editor" window.

Or... If you have Windows, get your hands on an old copy of "Lithunwrap" or buy a copy of "Ultimate Unwrap3D" and use it. I makes this type of UV unwrapping a cinch.

If you need more help, post here or go to www.blenderartists.org the folks there are really helpful. There are also a big assorment of UV mapping tools available as Python scripts. A search at blenderartists.org might find something to your liking.

Hope this helps.

 

in most of the game textures i've seen (including the unity fps tutorial weapons) any symmetrical faces, like the right left side of a gun, are usually only drawn in the texture map as one side.

i've been using lscm seams which work pretty well (with a bit of post editing), but of course the more space you have to work with the better. i think i'll try using the "from window" method you mentioned for anything i want to overlap, pin them lscm the rest.

i never would have thought to just overlay the uv faces, in all the blender UV tuts i've read the gist you get is that overlapping is bad. i'll have to check see if it works with the light baking script i'm using though.

thanks for your help ; )

 

After re-reading my post I just want to change one thing: For step "1" of the second method, if you want to over lay one map over the other, there isn't any need to have it scaled to 1/2, just have it projected to fit the screen. Experiment with the settings and see what works best for you. There are a number of Python scripts out there to do all sorts of projections, track those down (through blenderartists.org) and experiment with them also. Lastly, version 2.42 is due to be released "any day" now, I don't recall if any UV mapping changes are scheduled, but wouldn't be surprised if there were.

Good luck and have fun "blending"!

 

http://www.blender.org/cms/UV_Unwrapping.753.0.html

; )

 

This raises a good question, though: how bad is overlapping? I'm not using Blender but have had problems with strange tears in my textures when I try to overlap some parts of my model UVs in Bodypaint.

 

I used overlaping a lot in OF, both sides of the tanks and hummers use the same area of the texture, and so on. I didn't have any truble with it but I also didn't bake anything into the texture maps of those. If you plan to bake lighting or anything else into the textures each poly needs its own personal space on the texture. Jeff

P.S. I used BodyPaint for all the UVing of OF models.

 

The baking was the problem! Thanks.

 

Glad I could help, look forward to seeing what your working on Jeff