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Richard Hebert
10-04-2011, 05:57 PM
Hi Everyone,

This one is simple. Here's the scenario... I'm making a wooden plank in Modeler (hypothetically) and it's a standard size designed to scale... say 1" x 6" x 10' . I want to UV map this plank so I assign a map name and create UV's for it from the Y planar view and the new UVs spread out to fill the map area. Is there a way to keep the UVs to the same relative scale as my plank? I'm sure there is and I'm sure I don't know it! Surely when creating something complex I shouldn't have to try and scale all the UVs to some semblance of the object that I've created. Thanks for all the help so far and I'm sure I'll be able to assist others with all of the great advice from this forum.

Richard

hrgiger
10-04-2011, 06:31 PM
If you want to keep the propotions of your object, create a box around the object (imagine that box is UV space) and then UV both the plank and the box object. You're plank will remain the same in your UV map. Once the UV is created, you can delete the box, you don't need it anymore.

EDIT: And when I say box, I mean 2D. It's not necessary to draw a 3D cube.

Richard Hebert
10-04-2011, 08:31 PM
That really helps a lot. Thanks for the insightful tip! Just out of curiosity, anyone know why scale is not kept by default? I've not seen this in other 3d apps. Just wondering.

Richard

lertola2
10-04-2011, 08:41 PM
UV maps don't need to be kept in proportion to the object they map. By keeping your UVs proportional to the object you will probably will have a lot of empty space in your uv map.

-Joe

Richard Hebert
10-04-2011, 08:53 PM
If a map isn't proportional to the model, how do you map an image to an exported map without having to distort the image in the same fashion as the map? If I were to create the plank with a distorted map I would have to distort my image texture as well in photoshop. Seems like an unnecessary step to create a rather simple (albeit hypothetical) object. I tried this on a seagull model and had a very difficult time with the feather images. I also admit that I am quite a novice at texturing anything and some tutorials will be purchased ultimately.

JeffrySG
10-04-2011, 09:28 PM
^In that case the UV map would be non-proportional but you could still have the image be proportional to the actual object and when it was placed on the object with the UV it would still look correct but it would fill the entire UV space instead of only using a smaller % of the UV space. Sounds confusing but it's not once you get your head around it. Just make sure you layout your image based on a cropped screengrab of the actual model not the UV in that case.

Richard Hebert
10-04-2011, 09:31 PM
If a map isn't proportional to the model, how do you map an image to exported map without having to distort the image in the same fashion as the map? If I were to create the plank with a distorted map I would have to distort my image texture as well in photoshop. Seems like an unnecessary step to create a rather simple (albeit hypothetical) object. I tried this on a seagull model and had a very difficult time with the feather images. I also admit that I am quite a novice at texturing anything and some tutorials will be purchased ultimately.

Richard Hebert
10-04-2011, 09:35 PM
Sorry for the repost. OK, I think I understand your point. In the case of a bird, I wouldn't necessarily be using an exported map but rather a screengrab of one of the viewports to align the image to.

hrgiger
10-05-2011, 05:32 AM
UV maps don't need to be kept in proportion to the object they map. By keeping your UVs proportional to the object you will probably will have a lot of empty space in your uv map.

-Joe

Leaving space is not really an issue in UV map. The most important thing is laying out your UV's so that they make sense when applying textures. And if you do have a lot of extra space, you can always add additional UV's to your map.

JeffrySG
10-05-2011, 08:11 AM
Sorry for the repost. OK, I think I understand your point. In the case of a bird, I wouldn't necessarily be using an exported map but rather a screengrab of one of the viewports to align the image to.

Exactly. I use both methods. All depends on what I'm working on and how I feel at the time. If my uv map is just one large section I usually do it the non-proportional way. If I have many different parts on the same uv map I usually go with the proportional method. :)

kevman3d
10-05-2011, 01:02 PM
If its a simple one-off map - don't worry about the poly box. Just switch the UVmode from Automatic to Manual, then set X,Y and Z size to equal values. Its one less step to create box, UV, delete box...

However...

Using a poly box I found useful as a framing tool for multiple UV's - ie. when I wanted a few planar UV maps inside the same space, I could simply frame the "area" of the UV map I needed inside the box shape (ie. position the box around the object in a location where it would appear in the UV map itself)

kevman3d
10-05-2011, 07:19 PM
Just out of curiosity, anyone know why scale is not kept by default? I've not seen this in other 3d apps. Just wondering.

Oh, other app's do the same thing - For instance, Maya doesn't keep the scale initially either.

The reason is exactly the same, and that's because what happens is it will automatically create the UV map using a bounding box around the area of the selected geometry. Setting the size to equal values fixes this by forcing the bounding shape to be square. (the same as just adding a 2D box around your geometry, or manually setting this "bounding box")

This bounding area forms the 0-1 shape, and since UV maps are square, oddly shaped geometry will get "stretched" when converted to that UV space...

I did a quicky image to try and explain cause I'm starting to sound like I'm waffling meaninglessly. ;D

probiner
10-05-2011, 07:28 PM
For what is worth
http://www.youtube.com/watch?v=8eIiQboLUA4&feature=related

NanoGator
10-06-2011, 10:05 AM
An extra wrinkle in this problem is that the UV is being generated without knowing what the aspect ratio of the image that's being mapped to it will be. Also, how is Modeler to know when you're rotating a UV how to continue to maintain that aspect ratio.

It's not a simple problem, I think that's why they basically settled on UV values just being a number between 0 and 1.

I do recommend developing a habit of keeping texture resolutions to powers of 2. For example, my textures are nearly always 2048 by 2048 (or 2048 by 1024 if it's a rectangular image...) On paper it's not the most efficient method around, but my textures are all interchangable and I spend very little time having to do a lot of UV editing.

JeffrySG
10-06-2011, 11:08 AM
It's amazing that NT hasn't implemented PLG into the UV tools by now.

speismonqui
10-06-2011, 03:59 PM
It's amazing that NT hasn't implemented PLG into the UV tools by now.

or similar?