4
$\begingroup$

Currently, I am trying to cut my mesh in half with the knife tool, K. The cutting seems to work at the top and side of the mesh (I pressed enter), but it won't apply at the bottom.

enter image description here

enter image description here

enter image description here

Img1 and Img2 show the bottom edges which I am not able to cut. The knife tool won't even apply on these edges and doesn't change them into the red/purple color.

Img3 shows the cuts at the top and side which work perfectly fine. Without the bottom, I am not able to cut my mesh in half. Have I missed something?

Thanks.

$\endgroup$
  • 1
    $\begingroup$ Hi, welcome to the site. In future please crop your images to only the relevant areas and upload them directly to your question instead of linking to them. $\endgroup$ – Ray Mairlot May 19 '16 at 11:40
  • $\begingroup$ It's hard to make out what's happening in the images but have you checked your model for doubles? Go to edit mode, hit Atrl-A, then W - Remove Doubles. $\endgroup$ – metaphor_set May 19 '16 at 12:03
  • $\begingroup$ Try uploading a .blend file. Maybe also consider using Ctrl + R for Loop Cut instead of the knife tool (more efficient/easier). $\endgroup$ – Shady Puck May 19 '16 at 13:12
  • $\begingroup$ @ Ray - Hi, sorry... in future i'll do that, thank you ! ...... @ metaphor - My bad , you were right !!! after i used "remove doubles" it worked. Thank you so much !! ..... @ Shady - i'll keep that in mind. i like the loop cut function ! .... thank you all for your help $\endgroup$ – Roadhouseman May 19 '16 at 14:47
  • 1
    $\begingroup$ @Roadhouseman If you want to mention a user you need to make sure there is no space between '@' and their username, otherwise they won't be notified. $\endgroup$ – Ray Mairlot May 19 '16 at 16:46
3
$\begingroup$

Since you said "trying to cut my mesh in half ", is using the knife tool mandatory? Maybe you already discarded them, but there are other (probably better) tools, like the bisect tool, or the boolean modifier.

Bisect tool: this allows you to create edges through the whole mesh by setting a "bisect" line, like this:

  1. Start switching the 3D view in edit mode, and adjust view to allow you to "bisect" drawing on the 3D view, like:

enter image description here

  1. After clicking on "bisect", draw a single line (eg) from top to bottom: after confirming the end point, the cut is already done!

enter image description here

  1. Now your mesh has an edge that goes through all its geometry: you can use this dividing line as reference to delete all geometry (eg) to the right of it:

enter image description here

you'll get

enter image description here

Another way, as said, it using boolean difference, and since is a modifier, is also non-destructive (until you apply):

  1. Create a big cube that contains all the part of the mesh that should be "cut" away from the mesh

enter image description here

  1. Then select your mesh, and apply a "difference" boolean, with the big cube as target

enter image description here

  1. Done! Your mesh is cut, but you can still change cube (and this cut) position. Note that the cut zone ill be "closed" by a side - you can get rid of this after, if needed.

enter image description here

$\endgroup$
  • $\begingroup$ Yes, the knife tool can do what he wants, exactly the same way the bisect tool does. $\endgroup$ – Matt May 19 '16 at 15:40
2
$\begingroup$

Yes, you're missing something.

The Knife Tool can cut all the way through a mesh if you toggle "cut through" by pressing z. Notice at the bottom of the 3D Viewport after you press k to start the Knife Tool, there are instructions about the other functions the Knife Tool can use. It'll even show you whether "Cut through" is currently ON or OFF.

It also describes other functions of the Knife Tool that you might find useful.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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