Where is the command box in the bottom left of the 3D viewport?

Question

noob question...I have seen the same question asked many times but not really answered. All tutorials I have seen for 2.8 feature a small black command box in the bottom left corner, it's full of options for each command you select. Basically, you can't do anything without it. However, I do not have this box, so I cannot modify any settings as I create a feature. How do you get this box to appear?

I have seen answers featuring 'its in the 3D viewport' and 'hit F9'...neither of these seem to be relevant, as I'm already in 3D viewport and F9 will only shows the command I'd previously selected, but with no options. What is the answer? Very frustrating, please help.

Answer 1

This box is called the Operator Panel. It only appears after you perform certain actions, and often "disappears" as soon as you click away from it or you use any kind of transformation (move, scale, rotate, or when you click on another object).

For example, if you add a cylinder (Shift+A > Mesh > Cylinder), before you do anything else, look in the bottom left corner - there will be a little text box that only says "Add Cylinder". Click this box and it will expand for more options. Once you've expanded it once, it should appear expanded for all actions until you shrink it again (eg: other things you do, like add a loop cut will cause this box to appear "fully opened"). But, it will still disappear when you click away.

Keep your eye out for this box as you perform different actions (both in object and edit mode) - you'll be surprised how much it appears. There are lots of options that you can make use of through this panel.

Alternatively, you can use a floating window with the same options by pressing F9

Answer 2

The box is called Adjust Last Operation. If you do anything in 3D viewport like add/remove/etc it should be shown by default on bottom-left corner in 3D Viewport. If not, just simply turn-on when you are on Object Mode, go to View > Adjust Last Operation.

When you select anything else your Adjust Last Operation will disappear. If you want to get it back, go to Edit > Adjust Last Operation. Or simply press F9. (I used Blender2.91)