8 answers · asked · Lesson: Cartoon Head Pt. 3 - Neck and Forehead · Course: Blender Mesh Modeling Bootcamp

Fill a quad based on three vertices

I find myself doing this a lot:

  1. I'm selecting two edges (edge A and edge B), which is the same as selecting three vertices for current purposes, and these vertices define a plane. 
  2. Then I fill a triangular face (F)
  3. Then I essentially subdivide the newly created edge (Ctrl R
  4. And then I grab the blue square gizmo to move the newly created vertex along the plane of the face to make an approximate parallelogram. 

Rinse and repeat, rinse and repeat. 

There is an alternative method you use in your videos, which is to extrude edge C and then fill the neighboring face with the help of F2 addon. 

The reason I prefer to use the method above is that it keeps the face coplanar. And I find the coplanar method less fiddly, it is deterministic compared to the slightly "wobbly" extrude method.  

I essentially have already etched out the  defining features along all relevant axes, the path to follow is already determined, I am not making any form-changing decisions here, just routinely filling in the faces along the predetermined path. If that makes any sense. In fact, I want to do the same for the next face loop starting from the midline/forehead edge  on the left all the way to the edge above the ear on the right. And then the face loop above that etc. 

Or would you suggest I am going about this the wrong or suboptimal way?

If what I am trying to do is worthwhile, then the question is if there is any way to automate going from this:

To this:

Is there native Blender functionality that would allow me to create a face like that from two edges with a press of a button? Or is there an addon like F2 that automagically fills a face based on the three selected vertices? The location of the fourth vertex can be calculated deterministically because I am trying to make a parallelogram, which means that the opposite edges of this "rectangle" are to be are parallel. 

  • With the F2 Addon enabled, you select a Vertex like this:

    and press F to get this:

    • This is pure gold, such a simple solution and even less to select! And after hitting F just need to hit the right mouse button to fix the location of the new vertex. 

      To tap more into your magic spikeyxxx - perhaps there is a way to create a parallelogram from a faceless edge and a face as well? 

      (your method above does not yield in this case)

    • (your method above does not yield in this case)

      actually it does ;)

      Use Vertex Select Mode and select that corner Vertex :

      and press F:

    • Thanks it does indeed. 

      In my case it looked like it didn't, but on closer inspection it was because it had two equally valid options and it happened to choose the one I did not want (it created the face with the vertex appointed by red):

      But pressing F twice and then deleting the first newborn vertex does the trick.

    • It also depends on where your mouse pointer is, when you press F.

    • Sometimes it just feels good to be alive when you discover the ingenious ways people have catered for your job to be done.

  • crew

    Or would you suggest I am going about this the wrong or suboptimal way?

    Nope, this is also a great way to go! There are always pros and cons of each approach. Personally, I don't like to switch my orientations around that much, but that's probably just because I'm not in the habit of using the comma hotkey as much as I could. That's about as insignificant of a reason as you can get 😄

    spikeyxxx , I've used F2 for years and never knew of that function... Great find!