Guest Workshop: Blender - Cutting a hole into a model By: InsanitySorrow

[InsanitySorrow]

Cutting a hole into a model

Cutting a hole in a model is a question I've seen asked many times and something I wondered myself for a while, so in this tutorial we're going to cut a hole into a basic model.

Smarty Says: It is recommended you have at least basic working knowledge of Blender before attempting this tutorial as it does not cover any of the basics.

Step 1: Set Up

For this tutorial we're going to be using the basic cube model, this'll make it easier to see and understand what you're doing in each step.

Now for this tutorial we're going to cut a simple hole in the center of the cube, now to do this what we need to do is first add some new vertices to the model.

There are two ways we can do this, the first is to use the subdivide option, depending on the edges you choose this could potentially add vertices all around the model which isn't very clean and will bump up the poly count quite a bit.

So what we're going to do is use loop cuts instead, these are cleaner and will allow us more control on where the new vertices will go.

Step 2: Loop Cuts

Let's go ahead and select all then switch over into edit mode, make sure Edge Select Mode is on.

Right click on any edge to select it.

Now here comes the fun bit, press CTRL+R to select edge loops, here you will see a pink line around your model.

Smarty Says: When in Edge loop mode you can use your middle mouse button to add/remove edge loops.

Now you can move your mouse to select where it'll go (Vertical loop or horizontal loop)

After choosing it's alignment left click to place it, the line will turn yellow and you'll be able to place it in it's final position and hit enter to finish with it. Once finished the line will turn black like all the other edges.

Now for any hole you're going to make we need to make sure we have a vertex in the center of our hole. So for our hole we'll first need to make our vertex in the center of the cube since that's where ours will be. The first two edge loops we need to make are vertically and horizontally in the center of our cube.

Our next four edge loops should create a nice square shape around our center vertex, these will make up the sides of our hole.

Step 3: The hole

With those done we'll go back into Vertex Select Mode (CTRL+ TAB 1) and we'll remove the center vertex, for this we'll use the Box Select Mode (B), we'll make a nice box around the center vert (This ensures we select the verts on both sides) and hit X>Vertices to remove them.

This will leave us with a hole in the center

Smarty Says: Be sure to turn off Occlude Geometry so both of the center vertices are selected.

So there we have our newly cut hole, but there is one thing wrong here, we can see into the cube. So what we need to do is fill up the inner sides of the hole. To do this we'll select 4 vertices at a time and hit the F key to make a face, each side of the hole will require you to do this twice.

Once done we'll have a nice cleanly made hole in our cube.

Extra Step: Making our hole rounded

We have our finished hole and it looks good, but we usually don't see many square holes, so let's go a head and fix that.

Go into Edit mode once again, make sure we have our Edge selection mode turned on. What we need to do here to make a nice rounded hole is to add more edge loops, for this tutorial I have added an additional 16 edge loops, I added them in between the ones we made earlier.

Smarty Says: The more edge loops you create the smoother the circle will be, but do this with caution as it'll increase the overall poly count of the model.

With the vertices selected press Shift+ S and select Cursor > Selection, this will put our cursor in the center of our vertices.

Drag up the panel at the bottom of the screen and select the Editing tab (F9). In the Mesh Tools box click the To Sphere button and then click ok. We'll just go with the default settings here.

You'll see we now have a nice rounded top half.

All we need to do now is to repeat those steps on the other side to finish making a circular hole.

[Hanaisse]

This is awesome!

I made a hole!

[InsanitySorrow]

Well done Hana

[donnato]

Very well done IS. I might add a bit about having the occlude geometry deselected in order to select the center verts on both oposing faces at the same time.

[InsanitySorrow]

Thanks

[_echo]

I don't know all about blender.

But when I need to know, I ask IS.

(XX beer commercial reference)