Unwrap Stretching help

aajohnny

Hey,
I am trying to unwrap a tube for a mario level recreation and I am having problems with stretching on the model:

Model:


Stretching:



Anyone know how to fix this? any suggestions ( I am using 3ds max btw)

Thanks guys

elementrix

Your UV's for those faces have all edges straight, in the model the left and right edge of those faces are tapered to make the circle, so you are basically trying to fold a non-square piece of cloth into a square piece of cloth: you will get folds.

Just do a planar map on those faces and make sure they have the same shape in the UV editor as they have in 3D view.

aajohnny

Not sure if I follow you

elementrix

aajohnny wrote:

Hey im not 100% following you, what do you mean have them the same shape as the 3d editor? I do planar map those faces then when I stitch them it stretches.

It's because you stitch them, it probably changes the shape of the face in the UV editor so it isn't the same as in the 3d view.

It would really help if you show your UV's

aajohnny

Is this fine? or bad the top of the tube is showing green seems and the stretching comes if i stitch those

elementrix

As the image shows max is trying to fill up the red part of the poly to match up with the UV layout, you have to imagine that max always renders triangles, which explaines why you get that seam in the middle, and as you can see, the 3d poly in my drawing is showing you the same pattern.

Just imagine that you have a cloth on your kitchen table in the form of shape 1(in the drawing), when you take those 2 lower corners and move them to make the cloth the same shape as 2 you are going to get folds all over the place, in 3D you get these folds.

You have to notice how the horizontal lines on those poly's are still ok because you didn't change the upper and lower edge shape. So if you are going to add something that has a very stretched pattern like wood or a simple border you won't see any stretching showing up on the model.

aajohnny

That drawing is for the stretched part right? because in the uv I have has that shape for the stretched part:

elementrix

Yes that's for the stretched part, your latest 2 images show the solution to this problem so you don't get any stretching. You will get seams though so you have to decide upon what you want do based on how you are going to texture it.

aajohnny

Well, the good thing is that I am remaking the snes mario levels so you won't even see the top since it a sidescroller. I just want to know a solution just in case if it wasn't a sidescroller you know?

aajohnny

So if I brought this into zbrush and sculpted a bit it wouldn't be a problem? or would it.

SpeCter

You won´t get happy if you try to sculpt on this. It should be evenly divided.

I´m curious, what exactly do you want to do with it in zbrush?

aajohnny

Just add some noise on it.

cryrid

I think if you're recreating it in a manner that you plan on using zbrush and normal maps for it, you might as well go ahead and add some more sides to it so that the base mesh is rounder/smoother. I imagine you just want to add some highfrequency detail and not make major changes to the form/silhouette, so adding more geo to the base shouldn't create a problem (might as well add the loops to make the faces more squared as well).

Then again, if you don't plan on it being seen from other angles it might not matter much anyway (and in this case you'd be wasting time worrying about minor stretching on the bottom). Plan out the angle and distance it will be seen at, and go from there.

As an aside, zbrush doesn't really care about the UVs when it comes to painting and sculpting, so really you could just create the sculpt first and worry about the UVs later once you have something you can bake and test to see if it will actually be a problem or not. If it works, booyah. If not then you just change the UVs and rebake.

aajohnny

Thanks Cyrid. I am debating whether to just haindpaint and ignore sculpting all together or not. I want it to look good on my portfolio. Would you rather see a next gen handpainted industrial mario? or a more grungy next gen industrial mario?

renderhjs

haven't read at all but what you observed is called affine texture mapping - and its something that happens in the viewport of 3dsmax.

Nothing wrong with your UV's, propably all fine in your engine if it has modern GPU handling (corrected mapping) of those things.
If it still persists (depending on how your engine handles those things) you can subdevide things to even it out:

aajohnny

Oh wow thanks man! Hopefully Max 2012 fixes that . That's for that makes me feel better .

renderhjs

well its just a display in the viewport. Once you render its all fine, anything else is engine specific.