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AutoDesSys Forums » form•Z Discussion » Archive 2012 » Archive July - Dec 2012 » Problem with texture mapping of sphere and revolved objects in general « Previous Next »

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conroy
New member
Username: Conroy

Post Number: 4
Registered: 10-2012
Posted on Thursday, November 15, 2012 - 02:16 pm:   Edit Post Print Post

formZ 7.0.0.1
OS X 10.6.8

I'm having problems with texture mapping and I hope that it's merely user error.

1. I find the texture mapping on mesh triangles surrounding poles of a sphere to be wrong (except when the mapping type is "flat" or "cubic", but that's not useful to me). The mapping is wrong on display mesh and actual polygon mesh created from object during modelling or on export to OBJ. Material texture file and screenshots of a sphere with various mapping types follow.

2. I find the above problem plus other mismapped regions on revolved objects in general and only "flat" mapping seems to be reliable. Screenshot of example with cylindrical mapping follows.


material texture


sphere with spherical mapping


sphere with parametric mapping


sphere with uv mapping


revolved with cylindrical mapping
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support@formZ.com
Moderator
Username: Tech

Post Number: 18227
Registered: 04-2001


Posted on Thursday, November 15, 2012 - 03:09 pm:   Edit Post Print Post

Hi Conroy,

Mapping at the pole of a sphere will cause distortions inside the last set of converged polygons. If you just slice off a little tip of the sphere:

1

Then you should get something that looks nice in the Shaded (OpenGL) display, and exports nicely to OBJ.

application/zip2
sphere2.zip (885.6 k)


Does this help?
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conroy
New member
Username: Conroy

Post Number: 5
Registered: 10-2012
Posted on Thursday, November 15, 2012 - 04:35 pm:   Edit Post Print Post

Hi support,

I appreciate the speedy response but I'm astonished and saddened by it.

I've been a user of Rhino3D and numerous other modelling apps and all except formZ has been capable of producing correctly mapped meshes of spheres and revolved objects. I realise that there is a singularity at a pole and textures can be mapped with finite precision only, but as far as I know, only formZ produces these "swirls" across the ring of triangles surrounding a pole.

Slicing the poles off of spheres is not a useful compromise for me. Am I really expected to cut holes in every part of an object that has a pole? And did you notice the other errors in my revolved "bowl" example?

Here are screenshots of sphere and revolved "bowl" meshes produced by another app. They have the expected texture mapping. I could produce examples from other apps, but I think it unnecessary.


MoI sphere mesh


MoI bowl mesh
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conroy
New member
Username: Conroy

Post Number: 6
Registered: 10-2012
Posted on Saturday, November 17, 2012 - 11:27 am:   Edit Post Print Post

I'm disappointed by the lack of response to my examples of good mapping by another app. Does AutoDesSys intend to amend formZ texture mapping?
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robert smith
Senior Member
Username: Bob

Post Number: 946
Registered: 03-2002


Posted on Saturday, November 17, 2012 - 03:27 pm:   Edit Post Print Post

I'm sure they do. Sometimes more involved questions take a little longer to answer...
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conroy
New member
Username: Conroy

Post Number: 7
Registered: 10-2012
Posted on Friday, November 23, 2012 - 10:31 am:   Edit Post Print Post

Hi Robert, thanks for your input. However, my question wasn't at all complicated. It only required a "yes" or "no" answer from ADS. And still it is unanswered. And it's strange that Tech's usual "we'll get this corrected" response to a demonstrated problem is absent.

Here is an image of the UV mapping on the mesh generated from a Sphere by formZ to show why the swirls appear at the poles. The second image shows UV mapping which prevents the problem, in case ADS are interested.



formZ actual sphere mapping


desired sphere mapping


(Message edited by conroy on November 23, 2012)
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conroy
New member
Username: Conroy

Post Number: 8
Registered: 10-2012
Posted on Monday, November 26, 2012 - 10:39 pm:   Edit Post Print Post

Hello! Is there anybody there? Have I upset someone at ADS? Nice software but a shame that you treated a potential customer like a leper. Bye.
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support@formZ.com
Moderator
Username: Tech

Post Number: 18308
Registered: 04-2001


Posted on Tuesday, November 27, 2012 - 10:03 am:   Edit Post Print Post

Hi Conroy,

Sorry for the delay in getting back to you. We wanted to be sure that we had the correct answer for you before we replied, and now we have it.

This issue has been corrected for the next update. Please see a few sample images below:

1

2

Thanks again for bringing this to our attention, please let us know if you have any further questions, we would be glad to help (and we will try to be a little quicker next time!).