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UV Mapping on Shader Domains
Posted: 24 November 2012 03:53 PM   [ Ignore ]
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I must be missing a basic concept when attempting to apply a texture map to a shader domain on a vertex cylinder.
I have several tutorials and looked in this forum for more but I still don’t get some of it.
I am working in Carrara 8.1 Pro on Windows XP.
I created a cylinder in the vertex modeler and established 3 shading domains with the center being 70% of the over all length.
I copied the default shader, renamed it Center and applied it to the middle shader domain.
I then edited the Center shader with a Cylinder Projection of a texture map I created that is supposed to be a label on the shaft of a pen. The words on the label as applied to the object are warped. Which settings influence this outcome?

Thanks.

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Posted: 24 November 2012 04:46 PM   [ Ignore ]   [ # 1 ]
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The uvmap. Did you uvmap the cylinder?

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Posted: 24 November 2012 05:10 PM   [ Ignore ]   [ # 2 ]
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Just because you specify a cylinder projection on a cylinder doesn’t mean it’s going to be projected exactly the way you want, or expect. However you can see in advance how it is projected with the various methods in the UV unwrapping room, where you select the option to place the image you want to project in the UV map background so you can see how the unwrapped mesh relates to the image.

UV unwrapping often requires a bit of effort and trial and error, and sometimes manual adjustment of the mesh relative to the projected image. But without more information on what you did and are getting for results we can only guess at the fix needed.

BTW, just a hunch, but are you sure that your model is aligned along the X, Y, and Z axes and not at some angle? And are you sure you selected to cylinder project around the correct axis?

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Posted: 24 November 2012 05:16 PM   [ Ignore ]   [ # 3 ]
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I thought I had but I think that is where I am getting some steps confused.

I need the words in the label to line up with an indentation so I exported the uv map as a jpg to bring into my drawing program. I thought that process set up the cylinder correctly but it seems not.

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Posted: 24 November 2012 05:30 PM   [ Ignore ]   [ # 4 ]
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I am not sure how to have the image show up in the uv mapping grid but I will play around to see what setting I do not have correct.

The texture map on the cylinder is extremely stretched.

You make a good point regarding which axes I am using. I am not really sure.

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Posted: 24 November 2012 05:49 PM   [ Ignore ]   [ # 5 ]
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Don’t feel too bad…

IMO, Carrara is really, really bad when it comes to modelling and UV mapping. Personally I never (or very rarely) use Carrara for any modelling/UV’ing and instead use either Hex or some other program.

In any case, it sounds like you need to step back a bit and cover the basics of UV editing…what it does and why. It’s really a fairly simple concept, but when you try to learn it by first trying to figure out software tools it can be really, really confusing.

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Posted: 24 November 2012 08:30 PM   [ Ignore ]   [ # 6 ]
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HI Heavy D smile

You can use the Layers shader tools to create a Bottle label,

no need for UV unwrapping.

You draw the appropriately shaped layer for your image (label) directly onto the model in the shader preview window,.
you can resize it by dragging the points.

You can use it to place Stickers or logos, or use it in the Alpha Channel to create a hole.

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layers.jpgLayers_list.jpglayers_list_cube.jpg
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Posted: 24 November 2012 09:00 PM   [ Ignore ]   [ # 7 ]
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There’s currently a flaw in the Carrara UV mapper which moves an arbitrary set of points to the bottom corner on the UVmap when you use standard mapping. This then causes some distortion.
I export an OBJ and use UVMapper to correct those sorts of errors, then bring the OBJ back in.

The custom unwrapping works fine though.

I personally find the Carrara modeller to be very easy to use for producing any ad-hoc props that I often find I need in the middle of producing a scene. It’s particularly good for bashing around existing models.

Can’t lie though, if I could afford to buy one of the big guns I would but, for the money, Carrara will do.

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Posted: 24 November 2012 09:22 PM   [ Ignore ]   [ # 8 ]
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I am getting slightly better at UV mapping—but it took quite some time.

One this that can help when your textures appear warped and stretched on certain faces is to use a texture map of coloured squares (often with letters and numbers centered in them). You can then see this texture map in the UV unwrapping room behind the UV map. This way, you can make adjustments to the UV map before saving your model.

Use your favourite search engine to search images with the keywords “UV map textures” (or click here).

Hope that helps!

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Posted: 24 November 2012 09:27 PM   [ Ignore ]   [ # 9 ]
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RoguePilot - 24 November 2012 09:00 PM

There’s currently a flaw in the Carrara UV mapper which moves an arbitrary set of points to the bottom corner on the UVmap when you use standard mapping. This then causes some distortion.
I export an OBJ and use UVMapper to correct those sorts of errors, then bring the OBJ back in.

Yeah, that is pretty damned annoying. It has bitten me often and lead to confusing me further about UV mapping. I stare at the monitor wondering, “WTF did Carrara map it like that for?” sick

I am seriously considering getting UVMapper but haven’t yet. This might be the kick in the head that I need.

RoguePilot - 24 November 2012 09:00 PM

Can’t lie though, if I could afford to buy one of the big guns I would but, for the money, Carrara will do.

Agreed! I must confess though…I am taking very serious consideration with LightWave. Hey…at least I know it is being actively developed…

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- Garstor
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My 3D art Flickr page for final or near-final images
My 3D art Flickr page for work-in-progress or experiments

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Posted: 25 November 2012 04:25 AM   [ Ignore ]   [ # 10 ]
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Garstor - 24 November 2012 09:27 PM

Agreed! I must confess though…I am taking very serious consideration with LightWave. Hey…at least I know it is being actively developed…

The grass is NOT always greener on the other side. Really. I’d think long and hard before I made that step.

And I’d also suggest that folks download demos of some really good UV mapping software and try them out if you want to see what ‘good’ is when it comes to UV mapping. IMO, Carrara ain’t even close. But if it works for what you need then that’s all you need.

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Posted: 25 November 2012 07:07 AM   [ Ignore ]   [ # 11 ]
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I use carrara’s modeling room very little. I model and map with Hex. Free here in the store.

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Posted: 25 November 2012 07:19 AM   [ Ignore ]   [ # 12 ]
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Of course I have the free Hex…but I really haven’t explored it in any reasonable way. No one to blame but me there.

JM2K: True. The grass is definitely not always greener. Ignoring that sage wisdom ultimately cost me my job at Microsoft.

I am playing with the 30 day demo of LightWave. There is so much that it does vastly better than Carrara…yet there are things that are insanely quirky about it too.

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