To extrude something round from a surface, you need to make at least 4 faces. Use CTRL R to "Loop Cut and slide" and then SHIFT ALT S to force vertex points into a circle. Hit CTRL 3 while in Object mode to quickly apply a Subdivision Surface Modifier with level 3 detail. This video also shows some extra options when using the Knife Tool.
0:00 Intro
0:10 Octagons
0:27 Giftwrap
1:10 Subdivisions
2:21 Knife Tool Options
Watch video Extrude a cylinder in Blender online without registration, duration hours minute second in high quality. This video was added by user fxdojo 19 May 2022, don't forget to share it with your friends and acquaintances, it has been viewed on our site 8,20 once and liked it 5 people.