N-gons, most likey answered before, but I can't find an answer.

How does one go about turning n-gons in Cararra into polygons. I found a simple solution in Blender using the kinfe tool. The knife tool in Carrara decimates the vertex though.

Comments

  • DiomedeDiomede Posts: 15,026

    Check if something satisfactory for your needs is under the "Model" tab in the vertex modeler.

    For example, one of the options is "Triangulate N-Gons (>4 points)"

    Depending on circumstances, you might find something more appropriate.  For example, in the same general area of the menu there is an option to "untriangulate" and there are a couple of ways to address n-gons in the tesselate option, for example, esselate vertex to center and mid-edge to center.  A 5-sided N-Gon that is tesselated mid edge to center will be broken down into five 4-sided polygons, but that might create other problems depending on its own placement.

  • DiomedeDiomede Posts: 15,026

    Of course, I may have overcomplicated your question.  To do it by hand for a single polygon, you could use the link tool under some circumstances.

    cc01b link tool location.jpg
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    cc02b link tool usage.jpg
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  • I guess I what i'm really asking is how to turn n-gons into quads in Carrara.

  • Thank you Dimede_carrara. I The link/weld tool seems to act like the knife tool in Blender. It let me connect the vertices to create the quads on the flat side of a cone for instance. why does Carrara mesh tool creat objects in default mode with n_gosn? The Triangulate N-gons creates tris, which I am trying to avoid. The tesselate mid edge to center also seems to create fairly clean quads as well. I was just in a panic jumping around from software to software.

     

    Even crazier now to add to this is  how do I get a mesh object from Carrara into Sculptris.  Sculptris says the objects have no vertices. WOW! And Yes I realize sculptris uses tris.

     

    Question solved, but always leads to new questions.

  • wscottart said:

    Thank you Dimede_carrara. I The link/weld tool seems to act like the knife tool in Blender. It let me connect the vertices to create the quads on the flat side of a cone for instance. why does Carrara mesh tool creat objects in default mode with n_gosn? The Triangulate N-gons creates tris, which I am trying to avoid. The tesselate mid edge to center also seems to create fairly clean quads as well. I was just in a panic jumping around from software to software.

     

    Even crazier now to add to this is  how do I get a mesh object from Carrara into Sculptris.  Sculptris says the objects have no vertices. WOW! And Yes I realize sculptris uses tris.

     

    Question solved, but always leads to new questions.

    LOL triagulate polygon

  • DartanbeckDartanbeck Posts: 21,106
    wscottart said:

    Why does Carrara mesh tool creat objects in default mode with n_gons?

    I think it's because Carrara doesn't have a problem with them. I could be wrong. Some render engines perfer trigons over quads, others the other way around, as far as how lighting is handled during the render operation. I don't think Carrara cares one way or the other. So if one can reduce polygon count using an ngon, I think Carrara just says: "Go for it!"

    To do it by hand for a single polygon, you could use the link tool under some circumstances.

    This is what I do, but I don't consider myself a modeler... just someone whom creates models on occasion.

  • 3DAGE3DAGE Posts: 3,311

    HI :)

    In the Vertex modeller, you can use the Weld, or Link tool, and the Add vertex tool ,. these three functions allow you to add additional vertices or connect existing vertices

    how do I get a mesh object from Carrara into Sculptris. ?

    Select your model in carrara,. go to file/save as (or export) then select wavefront OBJ. that will load into Sculptris, Z-brush, 3D-Coat, or any other 3d app.

    why does Carrara mesh tool create objects in default mode with n_gons ?

    I'm not sure what you're doing , perhaps you're creating a primitive object (sphere cube cone etc) then converting it to a vertex model,. that conversion will create tri's which you can convert to quads in the vertex modeller,.

    If you're starting from ..Insert / Vertex model,. then the shape and structure of your model is up to you,.

    If you're using the spline modeller,. then converting to Vertex modeller, ..this will also create tri's,

    Hope that makes some sense

  • DartanbeckDartanbeck Posts: 21,106

    I think OP is talking about, for example, in the vertex modeler if we Construct a cylinder, the ends are n-gons. Same goes for polyhedron, cone, etc.,

  • TangoAlphaTangoAlpha Posts: 4,584

    That's also true for other modellers, such as Modo (for instance), and it's by design. If you take the end of a cylinder as an example, and you split it into quads either as a grid or a griddle, or into a fan of tris (Carrara's default triangulation method), you will have some very acute angles in the resulting edges. Should you need to work further on the end face - bevelling it, for example -- you'll find that the resulting bevel is neither neat nor symmetrical, and may even contain reversed edges, inverted normals and other nasties.

    The cleaning up of ngons is best left until you know you don't need to work further on that mesh.

    BTW, Carrara will automatically triangulate any ngons on exporting to obj or other formats, although it may not do it in the way you would prefer.

  • de3ande3an Posts: 915
    BTW, Carrara will automatically triangulate any ngons on exporting to obj or other formats, although it may not do it in the way you would prefer.

     

    Interestingly, my copy of Carrara does not triangulate when exporting to obj format. However I seem to recall a time when it did do this. Then after one of the updates it stopped triangulating (much to my pleasure). Now the original geometry is maintained in the obj file.

    I use the Mac version of 8.5.1.19 Pro. Perhaps the Windows version operates differently?

  • TangoAlphaTangoAlpha Posts: 4,584

    No, I use the Mac version too, and it definitely triangulates...

  • de3ande3an Posts: 915

    No, I use the Mac version too, and it definitely triangulates...

     

    Well, that presents an interesting conundrum.

    When I export a vertex object from Carrara and save it as an obj file, using the default export settings, the object is not triangulated when imported back into Carrara (also using the default import settings).

    See images below.

    Are you using a different workflow?

     

    Vertex_object.png
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    cylinder_and_polyhedron_obj.png
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  • 3DAGE3DAGE Posts: 3,311

    I'm with De3an on this one,.  i'm not seeing any triangulation on exported obj, ,.. I thought it may be related to smoothing ,. but no,. a quick test shows only quads

  • ProPoseProPose Posts: 520

    Don't mean to stick my nose in where it don't belong, but in my experience, (which is limited) if I export to obj out of the vertex modeller window the I end up with tris, but if I exit the vertex modeller and export out of the assenbly room then it keeps quads.

  • de3ande3an Posts: 915
    ProPose said:

    Don't mean to stick my nose in where it don't belong, but in my experience, (which is limited) if I export to obj out of the vertex modeller window the I end up with tris, but if I exit the vertex modeller and export out of the assenbly room then it keeps quads.

     

    All input is welcome.

    In the example that I posted above, I actually tried exporting from both the vertex modeling room and the assembly room to see if it made any difference. It did not. No triangulation occurred either way.

  • TangoAlphaTangoAlpha Posts: 4,584

    Hmm, you're right, it's not triangulating now. I'm sure it used to, but then I've reinstalled since the last time I did this in anger, so some setting may have changed.

  • wscottartwscottart Posts: 420
    edited February 2019
    3DAGE said:

    how do I get a mesh object from Carrara into Sculptris. ?

    Select your model in carrara,. go to file/save as (or export) then select wavefront OBJ. that will load into Sculptris, Z-brush, 3D-Coat, or any other 3d app.

    When exporting the object from Carrara I am taking the default settings for the wavefront obj files. They will not load in sculptris as that programs proclaims the object has no vertices, but  funny I created the object in Sculptris then took into Carrara for creating morphs. Also it will not load into blender 2.79 well it does but the object is I think mircoscopic. Strange it will load fine in daz and even into lightwave. Any ideals what I need to prep an object in Carrara for export as an object into Blender? Seems like the default to use to pretty much work for anything. I really have no reason to do all of this other than I want to be able to do it successfully.

    Heck the object will even open in zbrush. Why not sculptris or Blender?

    Also if i export it as a 3ds it will load into blender.

     

    Using Macos 10.14.3 and Carrara Pro 8.5

    Post edited by wscottart on
  • TangoAlphaTangoAlpha Posts: 4,584

    Obj files do not contain scale information, so they are always saved in the default units of the program that created them. For Carrara that's inches. Modo is metres, Blender I think is cm. Most importers allow you to specify the source scale, but Blender does not, so you have to rescale the imported mesh manually (scale to 254%).

  • 3DAGE3DAGE Posts: 3,311

    HI Wscottart :)

    it sounds like it could be an issue with that model,. personally i've never run into any problems exporting from carrara, with the obvious exception as Tango Alpha mentions above , that all programs have different workflows and scene settings, so some adjustments for each program are needed,. but ive never had the error message, that the object has no vertices,.

    If it's an object you made in sculprtis,.. it should go-Z to zbrush,. and there's a GOZ plugin for Carrara,. which would avoud OBJ

    But,.. it should also work as OBJ,.   so i'd have to guess at the model as the likely problem and suggest trying re-exporting , or try going through the process with a test object.

     

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