[tutorial] knife subdivide in a Flash


About 110 Ko, the very basics of the new knife subdivide tool.
Translation of my own French tutorial.

Help, critics welcomed.


Hey I like that alot. Explains it very nicely. Thank you! :smiley:


A good command to know when using the knife tool, since it leaves lots of tris, is Alt J for ‘convert tris to quads’

Thanks IamInnocent.

Modron, could you show a sample of one that has lots of tri’s? So far I haven’t seen it do this in the examples or in my experiments. Don’t get me wrong I’m not doubting you just curious.


Nevermind. I did some more experiments where I used the knife tool on the front face of a cube and the front face was fine but there were triangles on some of the other faces. Still very cool tool.
Paradox again

The knife tool leaves almost no tris at all.


The knife tool leaves almost no tris at all.


Let’s say that it leaves the minimum with perfect symetry in mind.
Two things :

  • at the start and the end of an inside cut there are tris that could be simplified a bit. There still would be one impossible to remove and there would be a loss of symetry that could hurt the model or not.
  • secondly, some faces often look like tris when they really are quads with three vertices in line, or almost, that make it look like there is only one edge.


Ok you guys are the expert. And even if it does leave the odd tri when I go on a pruning rampage, I am a huge fan of the knife tool. But if you want to see the knife tool leave tris, just cut a circle inside a circle that you just cut, and it will leave a few.

I just got done modelling a head, and this is what i noticed. The best way to see it is to take a cylinder, select the top faces, and cut either an even or uneven circle through the middle of all the top faces, and what you get, is, the inner row of faces, is still tris, but the outer row of faces, which you would want to be quads, is also tris. Of course you could use loop cut if you were just doing a cylinder, but for applications where the asymetrical placement of the points along the curvature is important, loop cut won’t do it. Don’t get me wrong. I love the knife tool. I’m just supporting my claim, that under certain conditions, it leaves tris.
<edit> btw I was wrong about the command. tris to quads is just J.