Question About Real World Accuracy in UV Unwrapping

Hello,

I am working on a small project where I am 3d printing a ceramic bowl and then adding a decal/stencil on the inner surface.

Something like this (this is a test render so please excuse the quality/composition):


I am thinking about exporting the UV’s as an Illustrator file so I can place the image , but how would I make sure that the image is seamless when I print out the decal?

How can I make sure the UV’s are physically accurate and to scale?

Is there a special way to Position the seams?

I have attached the bowl .obj so if you want to play around with it and give suggestions, feel free!

Thanks.

Since the surface of the bowl is not a plane, there’s no perfect way to use any kind of 2d support (except striping all triangles, as a paper model).

You can create two separate areas, one for the sides (cylindric wrap), and one for the center (top projection)… Your current texture is perfect for this method, but as soon as you have a texture where the sides and center touch, this method is more problematic.

https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Import-Export/Paper_Model
I’ve used this to get a shape out of Blender, then in Inkscape to match the right scale/orientation on a page, and print cutting templates out (for sheet metal).

The less distortion on the UV’s the better. Flat geometry doesn’t take round form very well without the material being malleable and even then, higher angle bends need cuts. That’s why leather, plastics, textiles, wood are heated when making them bend on a form they wouldn’t normally cover and conform to. But if you start with cut material that already has distortions in it, might be impossible to get it conform nicely.

Might be possible to use the pattern itself to hide seams that might be left visible when handling real materials. A straight cut in a wavy pattern probably is more noticeable than similarly wavy cut that might offset the colors slightly. But that might also make it harder to apply.

No you haven’t

Ooops. Thanks JA12

Here is a Blend file with the bowl

Attachments

bowl_Test.blend (1.48 MB)

And thanks for your quick reply Secrop