Blender Stack Exchange is a question and answer site for people who use Blender to create 3D graphics, animations, or games. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How can I get the knife tool to snap to the same spot on another edge to get a straight cut. Here is an example of what I want to do:

enter image description here

When the line turns green the cut is straight. How can I do this in blender? I have tried using the magnet snapping tool but could not get it to work.

share|improve this question
I think the closest you can get now is use midpoint snap (Ctrl) to snap both ends of the cut to the middle of the existing edges, then using edge slide (GG) to slide the edge over. Not very optimal, I agree.. – gandalf3 Apr 28 '14 at 0:00
up vote 19 down vote accepted

Press C while in knife mode to enable Angle Constrain.

Note that it snaps to angles relative to the view. For cuts on faces which are not aligned to any axis, you can:

  1. Press ShiftNumpad 7 to align the view to the face

  2. Press K to enter knife mode, then C to enable Angle Constrain:

    enter image description here

share|improve this answer

Angle Constrain

You can use C while using the Knife Tool to enable Angle Constrain. This will enable you to cut at the following angles (with reference to your current view):

  • Vertically

  • Horizontally

  • At 45° angles

Also, notice that when you start to use the Knife tool, the 3D View Header bar changes to show you all the available Hotkeys to perform all possible actions with the Knife:

enter image description here

  • LMB: Define cut lines


  • ESC/RMB: Cancel

  • E: New Cut

  • CTRL: Toggle Midpoint Snap

  • SHIFT: Toggle Ignore Snap

  • C: Toggle Angle Constrain

  • Z: Toggle Cut Through

(NOTE: It is common in Blender to have available Hotkeys shown in the 3D View Header bar while using a tool, so check there while using other tools too.)

share|improve this answer
Is there a way to snap the cuts to grid? – Alenanno Jun 27 '14 at 20:59

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.