Exporting Models

edited December 1969 in Carrara Discussion

I have already submitted a ticket on this but would like to see if I can get some additional help as well.

Currently I am using Hexagon 2.5 for making my models and then importing them into Carrara 8.0 for texturing and animation. I am also using Unity3d for my game design so I am importing all the items I am making into it. When I import the models from Carrara to Unity, my models will show up transparent on some if not most of the sides that are on the outside of the model. This only happens after I import my models from Carrara, not Hexagon as I have attempted to import directly from there and have no issues.

So far what I have attempted to do with the export from carrara is go through the file format of .fbx so I can keep the texturing and animation that I've worked on, as well as .obj and the issue persists. I have even attempted to just import the un-altered model from Hexagon to Carrara (and before doing anything) then export it in either .fbx or .obj and the issue persists (with .fbx it throws an error in Unity, the error is not very helpful as it only says to report the bug).

Here are the steps in detail
1) create model in Hexagon 2.5
2) export as .obj then import directly into unity (clean and complete model)
3) import .obj/.car into Carrara
4) export as .fbx (to retain texture/animation) and import to unity (transparency issue)
5) export as .obj (texture manually) and import to unity (transparency issue)

Any help would be helpful, I will be trying additional things to see if I can figure it out and will update as things progress. Thank you in advanced for your help.


  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    The issue is with back-facing normals. This has been an issue throughout C8. It causes the major hair bug, and also a render bug I pointed out a few months ago similar to your disappearing texture.

    If you can create textures that show on the back-faces in Unity, then you may have a workaround.

    See if you can flip the normals in Carrara's model room.

    You don't mention your bug# but if you can attach the before and after obj, it might help.

  • edited December 1969

    Unfortunately the only bug that I'm getting is when I import it to Unity in .fbx which is

    ImportFBX: Error
    Please report this bug

    That makes it really difficult to work with other than sending the information to either company.

    Do you know if this problem was fixed in 8.5 or if the issue showed up in C7?

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    I can't report your bug. You have the sample files and the screen grabs to show the issue. Please log on to the bug tracker, create a new account if needed. and write up a simple step-by-step tutorial on how to create the bug (similar to what you have done here). Attach screengrabs and .obj models to the report.
    To my knowledge it is aC8 bug and has been an issue that has been very hard to pin down and describe correctly, but it does seem related to several other issues (which have not been fixed as far as I know because the actual cause has not yet been discovered). You're information and scene files may help!

  • 3DAGE3DAGE Posts: 3,204
    edited December 1969

    HI TDGuy :)

    As Holly suggests, this issue is caused by the direction of the surface normals of your model, facing the wrong direction. this is not something that Carrara is doing,. It's on the Hexagon model.
    You need to check and correct any polygons which are facing the wrong way in Hexagon first, then save it out to Carrara,

    Hexagon can flip the normals direction of a single polygon, or a selection of polygons.

    Carrara can only Flip the normals direction of the entire model.

    Hope it helps :)

  • edited June 2012

    My current situation is as follows:

    direct port from hexagon to Unity (no issue)
    port from hexagon to Carrara (no issue)
    port from Carrara to Unity (issue)

    Also, I have attempted to correct the issue and no matter what I have done (check the polygons, verifying the verticies, limiting the amount of polygons) and again the issue is only when I export/save (from Carrara) as the file type that I need to port over to Unity that the issue happens. The confusing part is that if it is an issue with Hexagon, why is it that the issue only happening when I port from Carrara and not from Hexagon?

    I've also submitted a bug report while I'm still trying to troubleshoot this issue. I have found that maybe because I am not using the UV mapping that if I were to set that up, it may resolve this issue. Still working on it though.

    ***additional update

    I wanted to see if there may be an issue with the program and what I did was download and install Blender just to see how it would transition and the port over came through without any kind of issues like I was having with porting over with Carrara. Still trying to get Carrara working because I know that program better than Blender.

    Post edited by tims.guynes_89ffd32082 on
  • 3DAGE3DAGE Posts: 3,204
    edited December 1969

    Hi TD Guy :)

    I've just tried a simple vertex object and I'm not seeing any normal flipping in the FBX opened up in Carrara after export.

    In Carrara, you can use the Interactive renderer settings panel tio View the direction of the surface normals.

    In Hexagon,. you can use the (Utilities / Orient normals) option to see an arrow and you can unify and orient the direction of single polygons or the whole model.

    Carrara only has a one way "Flip" which effects the entire model. so that's why i'd think it's unlikely thet carrara is flipping a single , or several single polygons.
    Although it's always possible that this is happening on export to FBX.

    That's why I checked FBX export from carrara... I all looks ok here.

    Can you check the normal direction of your error polygons in your model in Hex, or just orient normals and try again. ?
    what version of Carrara, and What version of FBX ?

    800 x 744 - 146K
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