Spherical UV Mapper

Spherical UV Mapper

The spherical UV mapper doesn't work well. Previous forum comments indicate the problem is a Cheetah 3D quirk, not a mistake on my part.

http://www.cheetah3d.com/forum/showpost.php?p=95958&postcount=8

Attached are two renders, one from Bryce (a classic OS 9 3D program, for you youngsters) and a similar version from C3D.

I rarely need, or want, to use the UV Editor, for reasons most of you are familiar with. The basic UV Mapper projections almost always suit my needs. Sometimes I break up a model to apply different materials. The aim is to keep the process as simple and intuitive as possible. The spherical projection of an image onto a non-sphere is occasionally useful, and a Bryce-like function would be welcome. I hope it is something that Martin could easily add, maybe adapting a pre-existing free resource.
 

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Well - this works already when you use a subdivided Box (pretty sure Bryce is doing it the same way):

Cheers
Frank
 

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Yet more confusion

Frank Beckman to the rescue, #13,198. My first post betrays my ignorance about how the UV Mapper relates to the UV Editor. I should have posted a question in the General thread. Your answer got me about 90% to my goal. I want to finesse the proportions, and understand how this all works. As with so many seemingly simple effects, there is actually a series of steps required, any or all of which may be confusing. A couple follow-up questions?

As directed, I subdivided the box by giving it 10 X 10 X 10 sections before making it editable.

In the UV mapper: Spherical — Center projection — Write UV coords got me the results below. Note the curved part overhanging the left side and the long overlapping lines near the poles.

I have tried to duplicate your UV mesh, with the clean perpendicular right and left edges by cutting various seams, but got bad results. I tried pinning points and re-unwrapping, but that didn’t work either. Is there a simple way to make that adjustment?

How did you get the map image aligned with the re-proportioned mesh in your flattened image on the left? Did you need to save a PDF and use a separate program like Photoshop? I don’t understand the UV Editor enough to know if that picture is an integral step in getting the 3D results on the right, or just an extra picture to make the point that the spherical mapper works on a subdivided cube.

I am certain there are lots of C3D users who would benefit from any tips about UV mapping projections. Thanks again.
 

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The projection is automatic so to speak. To get a better alignment have a play with the X+Z position of the UV-mapper - no seams or other tricks needed - the rectangular texture will be displayed when "Edit" is enabled at the image loader.
A. Tweaked UV-mapper position.
B. Result of written UV coords - scale up
C. With snapping to raster enabled grab the corner points and take´em to its corners.
D. Perfectly spherical mapped cube.

Cheers
Frank
 

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  • SpericalMappedCube.jpeg
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Well OK then

There is no way I would have figured all of that out in a reasonable amount of time, if ever. Beyond helpful. Thanks.

Next: Icosahedron.
 

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Martin needs to fix this.

Cheetah 3D keeps crashing on my Mac Classic.
 

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