Boolean split or two object?


Does anyone know how to create the indentation in this level 1 excersise?
(P169) Im trying to understand the windows instructions on mac… getting thrown by the boolean task…
have tried to do the 'dir’command but not sure if this is the issue…

Extrude.3dm (4.0 MB)

Thats the wrong model… let me delete that and try and find the right one…

Extrudeattempt2.3dm (4.2 MB)

Boolean two objects worked for me. Did you click through the cycles until you got the desired result?

There are two naked edges in pink. That you might want to fix.

This seems much easier solved using trim rather than Boolean. If you are set on using a BooleanDifference, you need to flip both the phone and the cutter. You could also try Boolean2Objects, which lets you cycle through the results. But trim is much faster and straight forward.


Thankyou! Its part of an excersise, so id really like to get my head round boolean if possible…

Is the instruction you just gave; ‘boolean difference’ windows only? I cant see this on my menu! Im on a mac… I only can see boolean split or boolean two objects…

and im not sure what cycling through results means :confused:

I have been trying to switch the selections using ‘dir’ but not really sure what this is as there is no clear insrurction how t use this either…

Do you have a mac?


Im trying wth boolean two objects… but when I make the ‘two objects selection’ the whole front part dissapears leaving only the chunk remaining… where I want the opposite… I want the chunk dissapearing and the front remaining…

Dir shows which side of your surface is “outward”. If using Boolean this will determine in which side of a (cutting) surface the remnant parts are kept or deleted.

Edit: Yup, flip the white arrows using the Dir command (then click on the cutting surface), that should flip which part is kept and which is deleted.

// Rolf

Thanks! …ok so its dir that i need to figure out!.. i have applied it and it makes arrows go splayed out on objects… but not sure how to switch…

what object am I trying to ‘dir’? the green front? or the cutting object?

Extrudeattempt2.3dm (4.2 MB)

I seem to have got a step closer… but was expecting there not to be an actual hole…

Hmm, yes I am on Windows. On the Windows side, BooleanDifference can be used on the command line, and is also available through the Solid menu. Boolean2Objects lets you select two objects to Boolean, then you can left click to iterate through all the possible solutions, when you get the one you want right click or enter completes the command.

Over here on your model, BooleanSplit fails, but BooleanDifference and Boolean2Objects work (as does trim :wink: ).

On Windows, when in the Dir command, you can click the surface, or hit the ‘f’ key.[quote=“Ashley_Dell, post:10, topic:44197, full:true”]
what object am I trying to ‘dir’? the green front? or the cutting object?

From the original file you posted, you need to flip both of them.

I would think of Booleans as nothing more than intersect / trim shortcuts. They can save a few moments when they work well, in certain situations, but you shouldn’t feel like you have to use them, and often times (like this case) they take a lot more effort that finding an easier route. When Booleans fail, almost always the first diagnostic should be using Intersect to be sure the intersection is complete. If the resulting intersection curve is good, you can use that to trim, if not, it can show you where the point of failure is.


The best way to accomplish that goal is to learn how to model without booleans. No one ever gets there head around how booleans work by using them.

Booleans do nothing that you can’t do yourself. And the advantage of learning to do the steps yourself is booleans will no longer be a mysterious black box.