Quads vs Triangles

DarthDDarthD Posts: 221
edited December 1969 in Hexagon Discussion

When I model in 3D studio and save as an .obj then open it in Hexagon, it converts all the quads to triangles. The same thing happens if I model in Hex, save as .obj then open with 3D Studio.

Why does this happen and is there a way to prevent it? I would think an obj saved with quads should still just show quads no matter which program opens it.

Comments

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited December 1969

    When you export from 3DS as an .obj is there an export option to maintain the quads?

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited December 1969

    By the way, the reason I ask is because I have successfully imported quad objects into Hex. In my case I was using Carrara, but it does seem that Hex can handle importing quads. Some software as I recall only deals with triangles, not quads, natively, or at least during .obj import/export. But apparently Hex can handle them.

    So I'm wondering if 3DS is one of those tri's-only applications.

  • RoygeeRoygee Posts: 2,232
    edited December 1969

    Every 3DS .obj I've ever seen is triangulated, regardless of which application it is imported to, so, unless, as Joe asked, there is an option to export as quads, it seems that tri's is the default for 3DS .obj.

  • DarthDDarthD Posts: 221
    edited December 1969

    Yes, 3DS allows me to export as quads which is the default. I also have the option of triangles or polygons. It still shows up as triangles in Hexagon although hex will only open a .3ds file. It will not open a .obj file saved by 3DS. 3DS will open .obj files or .3ds files saved by Hexagon.

    Hexagon has Y and Z reversed for some strange reason, so I tried changing them when importing to match what Hexagon automatically changes them to when exporting to 3DS but the .obj files will still not open.

    Anything saved with Hexagon that I open in 3DS is in triangles also. I assume that Hex exports in quads since it is modeled in quads.

    The reason I want to open .3ds files in Hexagon, is I have a lot of items that I've created in 3DS that are untextured because I have a hard time with texturing in 3DS. It's a LOT easier to texture in Hexagon. I just don't like all the triangles and it takes forever to remove all the extra edges.

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited January 2015

    Not all file formats support quads as I recall. I know that .obj does, but it's quite possible that 3ds format doesn't. You might want to check online to see what you can find about that. But it seems clear that Hex and obj do support quads, so if you're not getting them then there might be something on the 3ds side that's causing it.

    Also, it might be possible that the software on either end decides to convert your quads to tris for reasons you may never quite understand, and only the software guys know for sure.

    Unfortunately, import/export has always been a challenging area when it comes to 3D stuff. Seems like it goes wrong more often than it works well. So I never expect much in that regard. Often your best choice is to forget the import/export and just do things from scratch. Even the "convert tris to quads" features rarely work the way you want.

    BTW, I'm kinda surprised that Hex won't open an .obj file exported from 3DS....seems strange. An obj is an obj, so it should work.

    Post edited by JoeMamma2000 on
  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited January 2015

    Well, I did some quick searching on my own, and I saw in multiple places that people are saying that 3DS format doesn't support quads, only tris. So I guess you're out of luck in that regard. If you can export in obj format it's likely your quads will be saved.

    EDIT: Oh, wait, I got confused...you did try exporting in OBJ and lost your quads. I guess it's just one of those things that only the software designers can explain. OBJ does support quads, as does Hex, so maybe 3D Studio is doing something goofy when it exports OBJ.

    Post edited by JoeMamma2000 on
  • DarthDDarthD Posts: 221
    edited December 1969

    I figured out how to get it to work. When I model in 3DS I always use Editable Poly. For some reason Hexagon does not like this and crashed when I try to open the OBJ.

    I converted my Editable Poly to an Editable Mesh before exporting to OBJ and Hexagon opens it with no issue, and it's in quads. Yeah!!!!! :-) :cheese:

    Now I can texture all my old stuff without having to start all over.

    Thank you to all who responded.

Sign In or Register to comment.