# Adding an edge loop to a pyramid

I have created a pyramid by adding a cube, then selecting the 4 upper vertices and clicking Alt + m, then "To Center":

I would not like to make the sharp top "dull".

There should not be a sharp end anymore, but instead I would like to create something like this:

To do that, I tried to insert an edge loop into the pyramid.

However, this doesn't work: It only wants to insert an edge loop at the "ground" of the pyramid (where we still have 4 vertices), but not on top.

I'm stuck. How could I resolve this?

Thank you!

Edit: I found out that the Knife tool allows me to cut my pyramid. Is there a smarter solution anyways?

• See blender.stackexchange.com/questions/24781/…. Sides of the pyramid are triangles which aren't available for cuting with Loopcut Commented Jul 17, 2019 at 21:26
• Instead of knife tool you can just select edges and use W->Subdivide operation, it works on triangles and N-gons as well. But just a thought: if you intend to cut off the tip, you already had a cube, you could have just scaled the top face smaller to achieve the same result. Commented Jul 18, 2019 at 13:16

One quick way is to use Offset Edge Slide tool. Select bottom face and run it (depending on the version) either with Ctrl+Shift+R or via viewport menus:

Add two edge loops on either side of selected loops.

Offset Edge Slide

Since there aren't any faces on the other side of the selected face before using the command, no extraneous edges will be added and you don't need to dissolve any unnecessary geometry in this case.

Not exactly an answer to your question, but there may be an easier way to make the surface in your reference, which shows you can leave the rounding to Catmull-Clark subdivision. Working in the XY plane....

• Start with a manually subdivided plane, (here, 8 cuts,) and from all vertices selected, in the header Select menu, hit 'Checker Deselect'

• GZ move the selected vertices up in Z, and assign a Subdivision modifier, level 2.

The subdivision on the perimeter is unconstrained by adjacent vertices, prodicing higher peaks, so we'll get rid of them.

• Apply the modifier
• With all faces selected, Select > Loops > Boundary Loop
• CtrlNumpad + increase the selection from the outside. I found 6 steps worked with this mesh..

Deleting the selected faces leaves you with a tileable section of a surface like the one in your illustration:

You can decide where to cut it and extrude the perimeter to give it thickness, when the size is settled.

EDIT: (response to comment)

This is working in the same way for me in Blender 2.80..

• Thank you so much! While not exactely the answer to the question, your approach is an amazing piece of art! Thank you!! Commented Jul 18, 2019 at 15:34
• With Blender 2.8, I don't have to apply your steps mentioned in the section ranging from "The subdivision..." to "this mesh.". With Blender 2.80 Beta, I can skip this step. I wanted to get these sharp for a test with the Modifier attached, but I can't get these sharp spikes. Do you think you could perhaps check this? Or is it too early with Blender 2.80beta? Commented Jul 18, 2019 at 19:58
• I have uploaded a video here that shows what I'm experiencing: youtu.be/baS_cHY3grg Commented Jul 18, 2019 at 20:05
• @tmighty.. see edit.. in the modifier, the UV settings and 'Use Crease' shouldn't make a difference here.. 'Quality' makes some difference at the corners, which will be deleted anyway. Is it just that you're not moving the vertices far enough? (Note dimensions) After nudging the checkerboard vertices up in Z, you can scale all vertices in Z about their median to give a more centered result.. Commented Jul 19, 2019 at 7:40

If you want to add a loop cut you can use the knife tool. Look at the pyramid from an ortho view such as the front. Select the knife K and then hit Z and C (K + Z + C). It will auto cut back faces (Z = cut through). Start the cut outside of the pyramid and drag across.

https://easyblend.org/html/modeling/meshes/editing/subdividing/knife_subdivide.html