Maya for 3D Printing - Rapid Prototyping
In this course we're going to look at something a little different, creating technically accurate 3D printed parts.
# 1 08-09-2010 , 06:14 PM
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texture stretching, where did I go wrong?

I modeled an anti-tank barrier for a HalfLife2 mod and then skinned it photoshop. It was a big step forward for me in terms of uving and then getting it all working and a working skinned material on the object but I see I have a lot of texture stretching.

Where did this occur do you think, in the uv when I was sewing edges or what?

what is the first thing that pops into your mind?


"Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety." -- Benjamin Franklin
# 2 08-09-2010 , 06:40 PM
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Did you apply a simple checker texture to your object while UVing? This helps to see areas of stretching and distortion which can be fixed by moving UV points in your UV tex editor. It's a matter of having the "faces" in the UV map roughly the same size and shape as the actual faces on your 3D model.

# 3 09-09-2010 , 11:37 AM
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stwert hit it on the head. I have had similar probs...the checker is the key for sure. Not everyone scales the UV though stwert...I have read elsewhere you can get more detail etc. I personally try to make my UV's the same or similar scale to the model as stwert said.

It also depends on the actual layout of the UV's too mate. If you have a rectangle....then the UV's should be rectangle...if you know what I mean.

I have learnt there is just as much work in UV as there is in modelling...dont just throw the sheet with the map over the bed without tucking it in so to speak. I fell for it at first...think..just paint shapes..throw sheet (skin) on and all is good. Well it didnt work.

I have also learnt that the actual model thought out properly and with little or at least mirrored geo...will make UV easier. I have seen one person who likes UV yet..LOL...but Im sure there is 1 person on the planet somewhere who loves it.

cheers bullet


bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes
# 4 09-09-2010 , 03:45 PM
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ok thanks that was a step in the tut I didn't do because I didn't think it mattered. silly me user added image


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# 5 09-09-2010 , 10:45 PM
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So applied my checker pattern like the tut said and I see my pattern is not lining up correctly. big surprise!

I moved my uvs around a bit in the layout editor but I can't ever seem to make them look perfect. some of my checker patterns are really screwed up like running diagonally or the pattern is way stretched to make the small boxes really long boxes.

I'm not uving complicated objects, just some box-ish shapes to get the hang of it.

I'm confident once I get past the stretching issue I'll be doing a lot better but I don't understand why this keeps happening??


"Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety." -- Benjamin Franklin

Last edited by n88tr; 09-09-2010 at 10:51 PM.
# 6 09-09-2010 , 10:48 PM
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Can you post a couple screenshots of your object and the UV tex editor with a couple areas circled so we know what corresponds? It might be a matter of rotating groups of UVs and moving lines of UVs closer or farther apart.

It's a bit unintuitive at first because bringing UVs together will actually create stretched areas, and moving them apart will created squished looking textures.

# 7 09-09-2010 , 10:56 PM
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ok sure

user added image

The tut I have is for a building and is way more complicated then I really need at this point. It's the haunted house one from this site.


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# 8 09-09-2010 , 11:00 PM
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Ok, I think I see the problem. It looks like you've done a planar map of the object, which won't be sufficient, since you need the sides to be mapped to an area as well as the front and back (which were parallel with your plane).

I would try either a cubic map (if that's an option, something like that anyway) or automatic mapping. That will ensure you have UVs specific to the sides of your object. Essentially the goal is to unfold the entire 3D model into 2D space, so any area on the model in 3D should have it's own corresponding area on the 2D area in the UV texture editor. I hope that makes sense and helps somewhat.

# 9 09-09-2010 , 11:03 PM
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Mate,

have you used create uv>planar or anything?? It appears form the pic you havent unfolded the models uv layout. Can you clarify this for me in case I am looking at it incorrectly?

cheers bullet

dont worry LOL stwert posted the answer as I was typing LOL..onya stwert


bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes
# 10 09-09-2010 , 11:12 PM
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ok thanks that gives me more to think about but when i unwrap it and the uvs are laying on top of each other, how do I know which direction to pull them away from each other? In the video the guy pulls his away and inward and I did that but I was just going through the motions and didn't know if it would work or not. you know what i mean?

there are so many unknown things i am doing without me knowing WHY i am doing them [just following the tut] or what IMPACT they will have it's hard to tell a bad action from a good action if you know what i'm trying to say.

i'll look at the cubic mapping. i tried automatic mapping just for the heck of it and it made my uvs all jumbled up so wasn't sure if that was the right option for me. like it takes a square i unwrapped and make it into a box within a box and that threw me for a loop.


"Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety." -- Benjamin Franklin
# 11 09-09-2010 , 11:27 PM
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Auto map will be fine mate. You then just have to cut and sew edges....

If you highlight the UV in the editor and keep the perspective window active...they will also highlight in there so you can see where they are.

It all seems daunting but it isnt once you do one LOL...I hate em!

As for knowing which way to pull...look for crossing lines..if they cross then the one you have should be on the inside of the shape...if you get my drift?

Try cubic...I have never used it...but give it a shot.


bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes
# 12 09-09-2010 , 11:29 PM
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I may have made up the cubic mapping, I'm sure there's an option for a 6-sided map, but can't remember where exactly.
You can turn on color shading for the UVs. If the area is blue, right way around, if red, you'll have to flip it horiz. or vert. If darker color, then overlapping area (think translucent colors)
Automatic mapping should work okay, but it takes a bit of work to get the final product. Separate out the pieces by selecting some UVs --> Ctrl+RMB --> to Shell, then move.
Get familiar with the Cut, move, and move and sew commands, they are essential.
UV mapping is tough to get started on, but with a bit of practice you'll be on your way soon.

Edit: Haha, I'll let you take it from here bullet... if you can beat me.

# 13 09-09-2010 , 11:47 PM
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Bahahah stwert you took the words outta my mouth mate LOL

I used auto map and really didnt have to sew the edges together but you can if you want. It started to deform quite a bit.

But stwert hit the target....


bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes
# 14 09-09-2010 , 11:58 PM
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I couldn't find cubic mapping, i think u made that one up guys. user added image

I tried the automatic on a new shape and it worked out alright. some of the edges on my object might new sewing but it's not that bad I don't think.

I think automatic might be the way for me to go for a little while. i'll keep playing with it for a while.

user added image

gotta work on my texturing skills. good thing i have a lot of saved up tuts for it though, been saving them as i go overtime ["this would be helpful to save when i actually start texturing" sort of thing doncha know]


"Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety." -- Benjamin Franklin
# 15 10-09-2010 , 12:27 AM
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Dont forget to use a ckecker pattern on your uv's first before you texture mate. The squares will make it obvious if there is any stretching etc before you actually apply your texture map.

cheers bullet

P.S I have made a vid if you want it?


bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes
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