Knife tool not working properly #37510

New Issue

Nikolay Naidenov · 2013-11-18T09:44:57+01:00

Nikolay Naidenov commented

2013-11-18 09:44:57 +01:00

Operating System:
Ubuntu Release 12.04 (precise) 64-bit
Kernel Linux 3.2.0-49-generic
GNOME 3.4.2

Blender Version: 2.69.2

Knife Tool Bug:
When using the Shift+K function and cut trough the whole object it doesn't cut trough some of the small faces (small compared to the rest of the object and the viewport) and it is not a problem with the object, it has been tested on other objects on different scenes and computers. I am applying a set of screenshot for beter explenation:

Thank you for your time :) !

Operating System: Ubuntu Release 12.04 (precise) 64-bit Kernel Linux 3.2.0-49-generic GNOME 3.4.2 Blender Version: 2.69.2 Knife Tool Bug: When using the Shift+K function and cut trough the whole object it doesn't cut trough some of the small faces (small compared to the rest of the object and the viewport) and it is not a problem with the object, it has been tested on other objects on different scenes and computers. I am applying a set of screenshot for beter explenation: ![Knife_1.jpg](https://archive.blender.org/developer/F28339/Knife_1.jpg) ![Knife_2.jpg](https://archive.blender.org/developer/F28340/Knife_2.jpg) ![Knife_3.jpg](https://archive.blender.org/developer/F28341/Knife_3.jpg) Thank you for your time :) !

Nikolay Naidenov commented

2013-11-18 09:44:57 +01:00

Changed status to: 'Open'

Nikolay Naidenov commented

2013-11-18 09:44:57 +01:00

Added subscriber: @kirompower

Howard Trickey was assigned by Brecht Van Lommel

2013-11-18 10:39:57 +01:00

Howard Trickey commented

2013-11-18 13:33:58 +01:00

kirompower, please reply and attach the .blend file that has the object in question, or any object that exhibits the bug. It is hard for me to reproduce such bugs without a .blend file.

Nikolay Naidenov commented

2013-11-18 14:26:17 +01:00

Here yoy go :) One object duplicated twice, one is the original and the other one is when it is already cuted ( I have deleted the faces below the cut line for better illustration of the bug )

1.blend

And if you want to make a object yourself here is a quick example: make a cube 1x1 meters, then Ctrl+A and S so it is in scale, then in edit mode apply bevel with offset of 0.0015 (1.5mm) and 3 segments and thats it, if you try and cut the whole cube with shift+K all the way trough it will leave some of the small "beveled" faces uncut.

Thank you :)

Here yoy go :) One object duplicated twice, one is the original and the other one is when it is already cuted ( I have deleted the faces below the cut line for better illustration of the bug ) [1.blend](https://archive.blender.org/developer/F28457/1.blend) And if you want to make a object yourself here is a quick example: make a cube 1x1 meters, then Ctrl+A and S so it is in scale, then in edit mode apply bevel with offset of 0.0015 (1.5mm) and 3 segments and thats it, if you try and cut the whole cube with shift+K all the way trough it will leave some of the small "beveled" faces uncut. Thank you :)

Howard Trickey commented

2013-11-28 03:45:11 +01:00

Are you sure there are faces there? After doing the cut, I deleted all the faces below the cut. I couldn't see any left that hadn't been cut. There are some edges left, but those don't seem to be attached to faces.

Nikolay Naidenov commented

2013-11-28 09:37:29 +01:00

Yep, there are faces, i think it is visible in the blend file I previously uploaded, but here are some screenshots to make sure

Thank you for your time :)

Yep, there are faces, i think it is visible in the blend file I previously uploaded, but here are some screenshots to make sure ![Screen_01.jpg](https://archive.blender.org/developer/F33533/Screen_01.jpg) ![Screen_02.jpg](https://archive.blender.org/developer/F33535/Screen_02.jpg) Thank you for your time :)

Nikolay Naidenov commented

2014-02-24 15:59:19 +01:00

I tested the same problem on the test build (2.7 from the link: http://download.blender.org/release/Blender2.70/) and it is still present, I have attached a video showcasing the problem.

Screencast_2014-02-24_16:50:37.mp4

Operating System:
Ubuntu Release 12.04 (precise) 64-bit
Kernel Linux 3.2.0-49-generic
GNOME 3.4.2

I tested the same problem on the test build (2.7 from the link: http://download.blender.org/release/Blender2.70/) and it is still present, I have attached a video showcasing the problem. [Screencast_2014-02-24_16:50:37.mp4](https://archive.blender.org/developer/F78753/Screencast_2014-02-24_16_50_37.mp4) Operating System: Ubuntu Release 12.04 (precise) 64-bit Kernel Linux 3.2.0-49-generic GNOME 3.4.2

Howard Trickey commented

2014-02-24 16:18:09 +01:00

I looked at this a bit, and think that the problem is that the distances involved are tiny, and we start to run into difficulties because of single-precision floating point tolerances. I don't know if I can find an easy fix.

Nikolay Naidenov commented

2014-02-25 09:18:13 +01:00

I don't know if this might help, but I am curently running v2.68 and it works fine.
Also I noticed that the problem seems to be relative to the object, I mean if I my cube is 10 times bigger and then I do the bevel again 10 times bigger, the knife tool still won't cut trough the small faces, despite they are now 10 times bigger but still relatively small to the cube (for example my original cube is 2x2 meters and the bevel was 1.5mm, if I make a cube 20x20meters and do a bevel of 1.5 cm the problem is still there)
Thank you for your time

I don't know if this might help, but I am curently running v2.68 and it works fine. Also I noticed that the problem seems to be relative to the object, I mean if I my cube is 10 times bigger and then I do the bevel again 10 times bigger, the knife tool still won't cut trough the small faces, despite they are now 10 times bigger but still relatively small to the cube (for example my original cube is 2x2 meters and the bevel was 1.5mm, if I make a cube 20x20meters and do a bevel of 1.5 cm the problem is still there) Thank you for your time

Nikolay Naidenov commented

2014-02-28 09:25:30 +01:00

Is there any way I can increase that precision ?