Home Technical Talk

Curved arches

Hey I was wondering how do I got about modeling (modular) arches that are curved such as those in the picture. Would I take a straight arch and use a path deform?

08060800282713928hdr2.jpg?t=1295898217

Replies

  • r_fletch_r
    Options
    Offline / Send Message
    r_fletch_r polycounter lvl 9
  • r_fletch_r
    Options
    Offline / Send Message
    r_fletch_r polycounter lvl 9
    There is no such thing as a straight arch. highlight what you want to model in the picture. I can see 3 or 4 different shapes you may be looking for
  • Maxim
    Options
    Offline / Send Message
    test.png?t=1295901179

    Notice how at the end of the hall it comes to a semi circular shape.
  • Sean VanGorder
    Options
    Offline / Send Message
    I'd say just model it straight and then use a few simple bend modifiers.
  • NBLM
    Options
    Offline / Send Message
    NBLM polycounter lvl 13
    I would model it straight+bend+symmetry and voila.


    edit:
    too late :/
  • Maxim
    Options
    Offline / Send Message
    After the bend should I just move the vets so that they snap to the gird and hallway pieces?
  • Maxim
    Options
    Offline / Send Message
    I was thinking about using a cylinder and using the cap segments as a guide to match up with the other arches
  • Sean VanGorder
    Options
    Offline / Send Message
    If you're concerned about keeping things exactly on the grid, you could also draw out splines from the top down view using grid snap. Then just deform the mesh along the spline.
  • Maxim
    Options
    Offline / Send Message
    I'm using 3ds max and I tried path deform world space modifier. I cant seem to get the curved pieces to line up to the straight ones. Its always a hair off.
  • Jeremy Tabor
    Options
    Offline / Send Message
    Jeremy Tabor polycounter lvl 13
    How about then collapsing the stack and manually place the vert where it is supposed to be so that it lines up? I mean, if it is only a hair's difference, the change in shape won't be discernible.
  • Maxim
    Options
    Offline / Send Message
    Ok, I was going to do that, I was just wanting to know if there was a mathematical formula that would help me solve this issue.
  • r_fletch_r
    Options
    Offline / Send Message
    r_fletch_r polycounter lvl 9
    It might be easier to do a loft. for the 'arch' and then poly model out from that. Since the Profile shape and the model are seperate you get alot of easy tweaking potential.
    http://www.cgrats.com/quickly-create-3d-objects-using-loft.html
  • Maxim
    Options
    Offline / Send Message
    Hmm, I will take a look at it.
  • Makkon
    Options
    Offline / Send Message
    Makkon polycounter
    EDIT: Oh, you got the answer earlier Maxim

    You mean like this? (except concave instead of convex)
    workshop5.jpg

    It was a serious pain to figure out, but once you got it down it's like cake. If Maya ran on this machine, I could SHOW you.

    Just a second while I write something up.
  • cman2k
    Options
    Offline / Send Message
    cman2k polycounter lvl 17
    ohh.....looking forward to it Makkon
  • Makkon
    Options
    Offline / Send Message
    Makkon polycounter
    Hope this makes sense...

    I don't have all the correct numbers memorized, so you may need to mess around a bit.


    -Start out by making a cylinder with the number segments equal to the number of arches you want. (like 16 sides, for example). Make it the size of the curve you want, but keep it about 1 unit high. Keep everything to the grid, including the radius.
    -Next, make another cylinder the same size, but something more like 128 sides, and about 64-128 subdivisions on the caps. Both of these cylinders will serve as a radial grid that you can snap to.

    -Create your arch in any fashion that you want. Just be sure that the geometry allows it to bend around a curve well. Keep it to the grid, roughly the same width as one of the faces on the large cylinder with 16 sides.
    -Move your arch to the edge of the large cylinders, and move it's center pivot point the the center of the large cylinders. This is the origin that your arch will rotate around.
    -Rotate your arch 11.25 or 22.5 degrees. (just depends on how many segments you made on the large cylinder). This should line up with one of the faces of the large cylinder with 16 sides.

    -Create a lattice around your arch. It should be 8 segments along the width, but the height and depth should only be one.
    -Use the large cylinder with 128 sides as a grid that you can snap the verts of the lattice to (make sure it's only along the z axis). Best to do this in the top view.
    -I would also suggest using a cylinder with 512 sides or so just to check and see that the curvature of the arch is right.
    -you may need to adjust the height of the arch to fix it's shape a bit.

    This creates an arch that you can duplicate and rotate along the center pivot that will weld perfectly together.
    Remember these angles.
    0
    11.25
    22.5
    33.75
    45
    56.25
    67.5
    78.75
    90

    I suggest you make whole modular assets in angle variations of 45, 90, 180, 270, and 360.





    let me know if that didn't make any sense at all.
Sign In or Register to comment.