Making Parallel Cuts

Support Modeling
1

Hi, I am puzzled about how to do this. What I want to do is make a set number of evenly spaced, vertical cuts, across a triangle face. I have tried removing the face (leaving the edges around it) and then subdividing each edge individually and then connecting vertices, but the lines are slanted and not parallel. Do you know how I would do this? I can’t use the knife tool, because for some reason the angle snap doesn’t work right, and it isn’t evenly spaced anyway.

EDIT: Solved!

2

Here’s two ways. Making a triangle after cutting, and cutting a triangle.

parallelcuts-triangle1.png1280×974 140 KB

  • Starting with a quad face
  • cutting it with loop cut (ctrl+r, scroll wheel)
  • using the shear tool with a hotkey ctrl+alt+shift+s, x/y (or MMB) to change direction left-right to up/down, and inputting a value -1/1 for -45°/45° angle. Here also using active element as pivot (hotkey alt+.)
  • same for other side
  • moving the edges with vertex snapping (ctrl+shift+tab for mode select, holding ctrl while moving) and removing doubles (w -> remove doubles)

Another, slower way is to actually cut the edges. This can be done with an addon tinycad vtx (I’m sure there are more).
You can search it with google if you don’t have it, download and install, and then enable it in addons.

tinycad-vtx.png816×516 55 KB

parallelcuts-triangle2.png1280×974 172 KB

  • starting with triangle face
  • creating a quad on top of it
  • making the cuts
  • removing unnecessary edges
  • cutting edges by selecting two intersecting edges and using the addon to cut it. It’s in specials menu (W) when enabled.
3

Ah, thanks! I think I’ll have to go with the second method, since the triangle is part of a model already. Still could be a bit tricky, for that reason. Any advice? Here’s the model I want to do this on (I need to do it to the selected faces):

http://i.imgur.com/StEqorq.pnghttp://i.imgur.com/2lal62m.png

4

Subdividing each edge and facing segments works, no?

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20Pics%202013/trysegment_zps6ada17fd.png

5

Yeah, I got a better idea too.

parallelcut_icosphere.png1280×974 72.5 KB

From top left:

  • Subdivide one edge 3 times so that it gets one vertex in the middle and one on each side
  • select top and bottom vertices and join them as edge with J
  • vertex slide (gg or shift+v) one vertex all the way to the corner
  • add loop cuts (ctrl+r)
    When done, select all and w -> remove doubles
6

Hey, that last one may just work. My main issue with subdividing was that the triangles are not equilateral, so the edges end up slanted. But I’ll try this method, I think that’s probably the solution. Thanks.

EDIT: Yes! It worked great. Thanks!

7

Actually one last thing. :smiley:

On a related note, how exactly would I make parallel slanted cuts in the inner set of quads on the top? What I mean is, I want to put cuts where the blue lines are in the image below, and they need to be parallel and evenly spaced, like before.


8

Use the knife with constrain angle on to cut from the righthand vertex to the lefthand edge.

cuts1.png865×718 44 KB


Then divide the top right and the top left edges into as many as required.
cuts2.png865×718 54.6 KB


All lines will be parallel, and all except the bottom line will be evenly spaced, but the distance to the bottom line will unavoidably be different, unless the face was already in just the right proportions.

Best wishes,
Matthew