Knife tool bug

[IHearNoise]

When I use the knife tool to split polygons, sometimes it creates randomly extra edges on other polygons. When I try to undo it doesn't undo the extra edges it creates, so I have to manually delete the extra edges.

This bug makes the knife tool unusable. Newest version in use. Same bug occured also on older versions.

[Carlosan]

Hi

I sent your report to the developers, thanks for pointing it out.

Could you try performing the same action in orthographic view?

[IHearNoise]

I don't have the exact same file anymore because I started a new mesh in Blender but I can try to redo my steps with that mesh In 3dcoat. I'm able to try in a week because I'm not at my computer at the moment.

[IHearNoise]

Okay I did some testing with a similar mesh I imported from Blender as in fbx into 3d Coat modeling room. First I deleted some edges from the top part of the mesh to create a similar starting point as before. I had the ignore backfaces checked on so the knife tool wont affect the faces behind the area I was working at.

When I used the knife tool in perspective view mode, the same problem occured instantly. Some polygons got deleted and some extra edges appeared near the cut I performed. The problem was worse when I was in fixed angle view(back, front, left...). But when I made the cut not in fixed view, only sometimes part of the edges didn't appear at all. 

But when I used the knife tool in ortographic view mode, I didn't get any extra edges or bad topology or any faces didn't get deleted. So the problems seems to emerge in perspective view mode.

Hope this was helpful and you look into this problem.