Captions: Here are 2 cubes we want to make a circular hole in each of them. Let’s start with the wrong way. Using a cylinder and a Boolean modifier as follows: First I'll select the cube in Object Mode, then press Tab to switch to the Edit Mode. Now press "A" to select all the cube vertices. Right Click with the mouse and choose "Subdivide". Then from the "Last Operation Panel" choose 9 Cuts to adjust your subdivision. Now press "Tab" to switch to the "Object Mode" so we can create a new Cylinder. Press "shift A" to add a mesh, then choose mesh, then cylinder. Rotate it on Y-axis 90 degree by pressing "R, Y, 90". Then move it on the x-axis towards the face you want to make a hole in by pressing "G, X, then drag the mouse until you get the desired position". Now select the Object you want to cut a hole in (the cube), then we're going to add Boolean modifier. Click on the Modifier Properties icon in the Properties Editor, then click on Add Modifier, then select Boolean modifier. From there choose "Difference" from "Operation" section and from the "Object" section just choose the cylinder object. Finally, press Apply and delete the cylinder by selecting it and pressing X while the mouse is in the viewport then choose Delete, or Press Enter. This way is the bad way and to show you why let's apply A Subdivision Surface modifier. Even if you increase the subdivisions to 5 in the viewport, the shape is still destroyed. Look at the artifacts in the shape. Let’s see how we should do the mission the right way. First I'll select the second cube in Object Mode, then press Tab to switch to the Edit Mode. Now press "A" to select all the cube vertices. Right Click with the mouse and choose "Subdivide". Then from the "Last Operation Panel" choose 9 Cuts to increase your subdivisions. Now choose Face selection mode, and select the square faces you want to make the circle in its size, let's say we will select those 9 faces. Press X then delete Faces. Now switch to select Edges mode, then (Alt click) on one of the remain Edge to select its loop. Now right click with the mouse and choose Loop Tools, then choose Circle. If you didn't find the Loop Tools menu, then go to Edit menu, then preferences, then Add-ons, then tick the mark that says "Mesh: Loop Tools". Now to test our circular hole let's add again a Subdivision Surface modifier. Also change the viewport subdivisions to 5 so you can see the best result. Now, look at the difference. You may now extrude the edges to pull out an arm or do whatever you want. Also we can check to see which one of the 2 cubes has artifacts caused by triangles or N-gons by the next steps: Select the first cube while in Object Mode, then go to the Modifier properties and delete the Subdivision surface modifier. Also select the second cube while in Object Mode and do the same by going to the Modifier properties and delete the Subdivision surface modifier. Let's now select the first cube while in Object Mode, then let's switch to the Edit Mode by pressing the Tab key. Now deselect all the cube vertices by pressing "Alt A" keys, then we are going to do a little test by selecting only faces that don't form a quad. Go to "Select" menu, then choose to "Select All by Trait", then choose to select "Faces by sides". That enable us to select all the faces that has or has not exact number of edges. Now, from the "Last operation" panel choose "Not equal to" and enter the number 4 as I'm doing. Now press Enter and look at the lower right corner where Blender gives you some information. Look for the number of selected faces and you will find that there is some faces that has N-gons or triangles. I'll make it up to you to do the same steps to the second cube, then you should find that zero faces are selected, which means zero N-gons or triangles. Thank you for watching and for more tutorials you're welcome to subscribe to my channel. Bye.
Captions: Here are 2 cubes we want to make a circular hole in each of them. Let’s start with the wrong way. Using a cylinder and a Boolean modifier as follows: First I'll select the cube in Object Mode, then press Tab to switch to the Edit Mode. Now press "A" to select all the cube vertices. Right Click with the mouse and choose "Subdivide". Then from the "Last Operation Panel" choose 9 Cuts to adjust your subdivision. Now press "Tab" to switch to the "Object Mode" so we can create a new Cylinder. Press "shift A" to add a mesh, then choose mesh, then cylinder. Rotate it on Y-axis 90 degree by pressing "R, Y, 90". Then move it on the x-axis towards the face you want to make a hole in by pressing "G, X, then drag the mouse until you get the desired position". Now select the Object you want to cut a hole in (the cube), then we're going to add Boolean modifier. Click on the Modifier Properties icon in the Properties Editor, then click on Add Modifier, then select Boolean modifier. From there choose "Difference" from "Operation" section and from the "Object" section just choose the cylinder object. Finally, press Apply and delete the cylinder by selecting it and pressing X while the mouse is in the viewport then choose Delete, or Press Enter. This way is the bad way and to show you why let's apply A Subdivision Surface modifier. Even if you increase the subdivisions to 5 in the viewport, the shape is still destroyed. Look at the artifacts in the shape. Let’s see how we should do the mission the right way. First I'll select the second cube in Object Mode, then press Tab to switch to the Edit Mode. Now press "A" to select all the cube vertices. Right Click with the mouse and choose "Subdivide". Then from the "Last Operation Panel" choose 9 Cuts to increase your subdivisions. Now choose Face selection mode, and select the square faces you want to make the circle in its size, let's say we will select those 9 faces. Press X then delete Faces. Now switch to select Edges mode, then (Alt click) on one of the remain Edge to select its loop. Now right click with the mouse and choose Loop Tools, then choose Circle. If you didn't find the Loop Tools menu, then go to Edit menu, then preferences, then Add-ons, then tick the mark that says "Mesh: Loop Tools". Now to test our circular hole let's add again a Subdivision Surface modifier. Also change the viewport subdivisions to 5 so you can see the best result. Now, look at the difference. You may now extrude the edges to pull out an arm or do whatever you want. Also we can check to see which one of the 2 cubes has artifacts caused by triangles or N-gons by the next steps: Select the first cube while in Object Mode, then go to the Modifier properties and delete the Subdivision surface modifier. Also select the second cube while in Object Mode and do the same by going to the Modifier properties and delete the Subdivision surface modifier. Let's now select the first cube while in Object Mode, then let's switch to the Edit Mode by pressing the Tab key. Now deselect all the cube vertices by pressing "Alt A" keys, then we are going to do a little test by selecting only faces that don't form a quad. Go to "Select" menu, then choose to "Select All by Trait", then choose to select "Faces by sides". That enable us to select all the faces that has or has not exact number of edges. Now, from the "Last operation" panel choose "Not equal to" and enter the number 4 as I'm doing. Now press Enter and look at the lower right corner where Blender gives you some information. Look for the number of selected faces and you will find that there is some faces that has N-gons or triangles. I'll make it up to you to do the same steps to the second cube, then you should find that zero faces are selected, which means zero N-gons or triangles. Thank you for watching and for more tutorials you're welcome to subscribe to my channel. Bye.