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"Duplicate with Symmetry" inverts normals

evilnoodleevilnoodle Posts: 0
edited December 1969 in Carrara Discussion

Hi all,

I have recently started using "Duplicate with symmetry" quite a lot to speed up my workflow however it appears that the use of this option in either the assembly room or vertex modeller inverts the normals of the duplicated part/s. Things appear largely ok while still in carrara but on export to .obj the duplicated objects have their normals inverted which is a pain.

It isnt a deal breaker because I have workarounds for both cases but they are fiddly and error prone so I was wondering if anybody knows if there is a way to prevent this?

Cheers

EvilNoodle

Comments

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    HI Evilnoodle :)

    I'm not seeing this,.

    I just tried making a simple vertex shape, Duplicate with Symmetry , in the vertex modeller, Export as OBJ, Import into Poser, (it's View-port renderer doesn't display back-facing poly's, so it's a quick test of the normal direction.

    I also tried Duplicate with Symmetry from the Assembly room,. and export as OBJ , Import to poser, no visible issues with the duplicate.

    Can you give some more details, EG: what program are you opening the obj in

    pics are always handy.

    PP_Norm1.jpg
    1312 x 1050 - 160K
    C_Norm1.jpg
    1256 x 976 - 268K
  • evilnoodleevilnoodle Posts: 0
    edited May 2014

    Hi,

    Thanks for looking at the problem!

    How did you get Carrara to display the normals? I can't see an option anywhere!

    I am trying to export to Ultimate Unwrap 3D to UV map and a range of other tools.

    Below are some screenshots showing the problem with a test object where I used "Duplicate with Symmetry" in the vertex modeller and welded the centre together...

    In Carrara it looks fine but in Ultimate Unwrap the normals are clearly inverted on the duplicated side of the model. In substance designer this also appears to be the case with half the model not rendering properly.

    Thanks

    EvilNoodle

    Unwrap.png
    1010 x 704 - 70K
    Substance.png
    850 x 729 - 743K
    InCarrara.png
    1039 x 788 - 167K
    Post edited by evilnoodle on
  • evilnoodleevilnoodle Posts: 0
    edited May 2014

    Just found how you made the normals visible. Very useful!

    They appear fine in Carrara but on export to obj and import into Ultimate Unwrap, Substance Designer and 3D Coat they are inverted for the duplicated parts of the mesh so it must be happening on export or all those tools are importing wrong. Given I don't have a problem importing .objs from blender or other modellers I reckon its probably a weird export thing.

    Sadly I don't have poser so I cant test it using that.

    EvilNoodle.

    Post edited by evilnoodle on
  • 3DAGE3DAGE Posts: 3,311
    edited May 2014

    I tried importing the OBJ into 3D coat, for Painting and UV mapping,...No issues with the normals ,.

    So,..I'm wondering if you're using the automatic weld in Carrara, or if you're taking the time to manually position the duplicate and original,. then weld them together.

    just tested this idea, and can confirm that Carrara can flip the normals direction on the duplicate,. when the Auto weld option is used.

    Manually welding the duplicate, and original model,. works as expected.

    I think this should be reported as a Bug,. as it's not the result the user should expect.
    Nice find :)

    Hope it helps


    Just to add one other point,. ..

    For the model you're showing there's no real "need" to model half and use Duplicate and weld.
    It could be made easily by extruding a box, and you can model with symmetry enabled to create both side at once.

    coat_UVs.jpg
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    autoweld.jpg
    438 x 148 - 10K
    Post edited by 3DAGE on
  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Not to hijack the thread, but is evilnoodle more evil than evilproducer? Time will tell! ;-P

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    No one can be more evil then the producer of all evil.

    ......Or can they be....

    I've never met a noodle I didn't like.

    ....Or have I just met the most evil noodle ever,....

    surely not.

  • evilnoodleevilnoodle Posts: 0
    edited May 2014

    EvilProducer you are right. Only time will tell MWAHAHAHAHAHAH!!!!

    3DAGE Thanks for your help on this. The model in the screen shots is just a simple test model I made to illustrate the problem. The real model I am working on is much more complicated but I believe in giving the simplest example of issues I can to limit the variables that apply. Guess it comes from my software development background.

    In the example I gave I allowed Carrara to weld the verts but I will give it a try with the manual welding. Using the "Duplicate with Symmetry" still seems to invert the normals when used in the Assembly room on whole objects so it still needs reporting. I will see what I can do in terms of submitting a bug report tomorrow.

    Thanks for all the help, it is nice to be among helpful people!

    EvilNoodle

    Post edited by evilnoodle on
  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    Thanks Evilnoodle :)

    Yes, you're right, it'll flip the normals on the duplicate whether you use the automatic weld option, in the Vertex modeller, or the Assembly room, since it's using the same function.

    One quick fix is to use,.. Model / Flip Normals.

    This will flip all the normals in a single direction, which may then need to be flipped again depending on the direction you want.

    so, if you use Auto weld,. then flip normals twice, you should be where you wanted to be.

    :)

  • evilnoodleevilnoodle Posts: 0
    edited December 1969

    I have just submitted a support request for this issue so I will update this thread as and when I hear anything.

    Thanks for all the help!

    EvilNoodle

  • 1MoreThreadDeleted1MoreThreadDeleted Posts: 56
    edited December 1969

    This problem has been around a while. I have C7 installed and it does it too.

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