Boolean Theory for Blender - Why it matters

greetings hobbyist this is alans of v and in this video we're going to have a look at some Boolean Theory while creating this jet engine exhaust so this video is going to be quite beginner friendly in that it deals with some relatively simple Concepts to understand however in reality there's a lot of people that I'd put at an intermediate or maybe even a high intermediate level that don't seem to consider these things in their workflow and that's okay cuz this can seem like a bit of a pedantic thing and I like pedantic details but it can be really important in decision making but if as a beginner you can learn this early on you're going to save yourself a lot of annoyance unlearning bad habits later and actually thinking about what you're doing to make a decision that's right for you so the way we're going to do this is I'm going to set up everything and all the booleans that are part of this jet engine normally you do this bit at a time probably but the order you do it a bit in a time and booing everything together is the important bit so let's start by making a cylinder I'm going to up this to 128 vertices so it's quite nice and round IM model for 3D printing so we want everything being quite smooth let's s to scale it up controll and a and apply the scale and then I'm going to go into face mode I'm just going to S to scale that down a little bit and then G and Zed to make that a little bit more dubby in terms of height then we're going to want an object to cut out the center now you could do this by using the I to inser and then e to extrude down but we don't want that we want something that we can change later on so that wouldn't be as appropriate as is what we're going to do in this instance cuz we might want to change it later so I'm going to shift and D to duplicate it right click and then s to scale this down get it to about the thickness you want the walls and then G and z and just bring that up so it just sticks out the top so we've got a little bit of an overlap and as we're going to use this to cut out the center I'm going to press f2 and call this Center cutter then we'll make the object that's going to cut out the detailing around the sides so let's shift a mesh and bring in a cube s and then y to scale it on the Y AIS something kind of small there let's s and then Zed to scale that up let's go with about that maybe actually a bit higher so we're above the bit that's going to cut out the center so let's just go to there and then we'll s and then X to scale that on the x axis contrl and a and apply the scale again and just add some interesting detailing let's go into Edge mode I should say that when I press Tab and you see these different modes here that's because I'm using machine tools Machine Tools is a $5 add-on that's got a load of extra features as well I really like this because I find it quicker to use but the main reason I'm using this is because it means it's very visible what mode I'm going into when I do tutorials so you don't need to use this for this you can be perfectly happy just using Tab and then coming up here all one two and three to change between the modes let's control and R to bring in an edge Loop go to about there and click and then go into face mode and to select that face and that face and press alt and E to activate our extrude options click extrude faces along normals and bring that out to about there then we'll go back into object mode with Tab and I'm just going to shift and D to duplicate it press R and then Zed to move that or rotate it around the Zed axis and just type in 90 we can see that goes in the top left hand corner to say what we're doing hit enter and then we've got this slight issue with some face fighting here which can cause Boolean errors there are a lot of ways around this but I'm going to go with a slightly lazy way of just pressing g z and just moving this up by the tinest of fractions and then we've got that ready to go now we are going to want to Boolean these together into one object and we're going to be using Boolean a lot so if you haven't activated an add-on called bull tool it comes with blender just type in Bull and then activate bull tool and then you've got that good to go and that means that instead of having to go to the modifier menu here you can just click and then shift click press control and then Plus on your number pad to do that Boolean and I'm just going to select that second object and press h to hide it and then because we're not going to change this object let's just go into our modifier menu and then apply this then finally when I cut this out this is going to cut all the way through the object but I want to add almost like an inser here you'll see what I mean as we do this if you're not sure what I'm talking about so I'm just going to come back to this object object shift and D escape and then s to just scale it down a little bit we'll go with something like there and that will work fine now let's name everything we've already named this to be our Center cutter I'm going to press f2 and we'll call this detail cutter and then I'm just going to go into x-ray mode and select the one that's here and we're going to call that F2 we're going to call that inser cutter so we've now got everything that we need ready to go and I'm going to call this collection so let's just rename this example one and then what we're going to do is Select everything that's here shift and d and then X and then I'm going to press M to move this to a new collection we'll call this example two okay and then let's do the same thing shift and d and then one more time and then M I'm going to call this example three so I'm just going to reorder this so it's a bit clearer so we've got example one these objects example two which are these and then example three which are these and we're going to Boolean these each in a different order and talk about well what's the right order the wrong order and then why now just as a side point there isn't really a right and wrong order the one that I'd probably say is most wrong is going to be the one over here I think it actually causes problems but we will even look at a situation why this would be potentially correct so we will talk about the positives and negatives of all of them so let's start with this method over here now what I'm going to do is start by deleting out the center section so I'm going to select my Center cutter shift click control and minus and then we've got that cutting out the middle I'm actually going to get rid of the inser cutter for now just so we can see what's going on and then we'll select this shift click and control and minus here as well so we've now got this object and we're cutting all the way through but I actually want this to be an inser so I can see this detailing but it's more structurally solid which is useful if you're 3D printing and it also gives you somewhere if you're painting it that you can sort of put inks into and it actually almost accentuates the detail even though there's something there so what I need to do is bring back my inser cutter and I need to add this so click and shift click and Control Plus back to my object the only problem is I'm just going to H to hide that detail cutter is that now it's totally encompassed the middle section ction so I'm going to go back to my Center cutter find my inser cutter which is here I'll just click over here using control as it's a bit easier than selecting it this way and then control and minus and cut that out again so we've cut the center section out of the original bit and then we've also cut it out from the middle so let's just H and H and then we'll come back to this and why this is probably not the right choice but you often see people doing this and ending up with this order structure if you're creating your Cutters as you go now this one's going to be a bit more of a sensible ordering what we're going to do is I'm going to click the detail cutter shift click the main object control and minus to cut that out and then we can H to hide this cutter then I'm going to take the inser cutter the one that's adding the inser and then shift click and control and plus to then add this to this object so now we've got one thing that is here and then finally we can take the center cutter click and control and minus and that has deleted everything out last which is a little bit more efficient and we'll talk about why and the positives and negatives of that the final method which I would say is generally the better one but it's up to you and what you're doing is to actually look at this detail cutter and think about this first what I'm actually going to do is take my cylinder that's the main body and I'm going to hide that over here and I'm going to realize that this inser if I remove this from the detail cutter then I'm not going to have to add this in later so what I'm going to do is find my insert cutter shift click control and minus and cut out a section of what is going to be this detail cutter what this then means I can do is bring back my cylinder and delete this from the cylinder and you'll notice that it is added that inser perfectly all in one go click there H and then I can delete out the center so that's H to hide that as well so we've got three objects object s here that theoretically are identical there's no difference between the end result in theory but there is actually quite a lot of difference so let's start with this one now this one has got a problem our example one has got an issue and that issue it's not a massive one but it can cause a lot of problems is that we have to delete our Center cutter from the main object but we then realized we had a problem and also deleted it from our inser cutter so if I click on the inser cutter we can see we've deleted that Center cutter from that as well now what that means is that if I'm going to choose to move my Center cutter at any point it is simultaneously affecting two objects at the same time so if I press G and start moving this around you can see it's a little bit jerky that's because it's trying to affect two objects at the same time and blender's trying to do more maths if I just Escape out of that whereas in any of these other two we'll just pick this one if I turn my Center cutter for this one and press G you can see I don't have that stuttering that you saw so I could then move and change this let's say for example I decided to scale this Center up and it's not causing blender to have to do more computations at the same time so this slows down the process by having it act on two objects I'll also say that doing it this way can cause problems with the mesh when you combine them together and you can actually see there's starting to be a bit of an issue here because the Cutters are getting confused being on top of each other so generally you want to avoid having one cutter cutting through multiple objects now there are exceptions to every Rule and I think it's important I point that out so what I'm doing now is creating something that might be like a hinge joint and creating something where we're going to want a hole going through separate objects so with this realistically we're not going to want to Boolean this object to this object because they're not actually touch ing in any way so we're going to come here control and minus and then here and here and control and minus and in this instance this cylinder is acting on both this object and this object so it is an exception to the rule but here that's really important exception cuz if I want to let's say G and then why and move this I need it affecting all of those objects or it's going to be a pain to make sure that that lines up so as I said there are exceptions to the rule and we always need to bear that in mind and I wouldn't want to miss that out now this object has some positives to it and the main positive of doing it this way is that everything was Boolean out of the final cylinder that we can see at the moment everything is hidden and we can just see this object and that means that when I click on it I can see all of the modifiers over in my modifier panel that are acting on this object I have instant access and can view each one of them very very quickly now that's nice because I can have a quick cursory glass at what I'm doing which is always helpful and if you have got something like the add-on hard Ops which is an absolutely amazing add-on there's a link in the description where I've got a playlist on that I can use one of the functions which is called everscroll to then scroll through all three objects that are acting on my cylinder and I can quite quickly come to one of them click them and then modify it so that's a useful feature of this that we have them all there and visible in one go let's just H tide that now this one is actually my preferred method and that is because having the insect cutter remove itself from one of the other Cutters means that for my cylinder I now only have two Boolean activated now this is slightly more efficient for blender from what I can tell CU When you get into really complex object with lots and lots of booleans it seems to have less problems moving any of those individual Cutters and modifying them so from my experience anecdotally this is more efficient for blender and how it processes everything the other thing that's nice about this is I'm only dealing with those two Cutters it makes this less messy it also adds a nice hierarchy so for example here if I do use that ever scroll function and say well that's the center cutter that's the detail cutter I've only got those two to look at and consider so say for example I wanted to come to this one and then click on it and scale it up I can do but if I do want to access the detailing I can come to the detailing and then now while I'm using the detailing I I can for example see just the union that's affecting this detail so it means that this is obvious or at least more obvious in what this Boolean is doing and again if I've got hard Ops I can ever scroll and then come to this one so it adds a nice hierarchy where you can move down your different objects and know which one is affecting which whereas with this one the idea that this insect cutter is having an effect on the detail cutter isn't as obvious now either way for this the final stage is to shift an a mesh bring in a cone and then we can see that cone here let's put that to 128 then we're going to add to the depth probably somewhere about there and then add to that radius one and then in cross-section we're just going to have to see that we're going to need G and Z that down slightly and then we can Boolean that in and we've got our jet engine and I just wanted to finish that so you know how we would end this and we would then click shift click control and plus to add that in now we could do that with either of these objects as I said I don't think this is a very efficient way of working and it's going to cause you problems in the long run if you're making a complex object one of these is probably the better choice it just depends on how you like your Boolean being shown in the modifier panel and if you prefer that hierarchy hopefully you found that useful if you did please do hit the like button it does help spread the video around if this is something you already considered or don't or if you think this is a complete waste of time do feel free to say in the comments section I got called blender nerd the other day because I think about these things but you know what I'm perfectly happy with that if it's going to make me more efficient in my modeling and I'm not sure what the person expected when going online and watching a video on blender on YouTube and for most of us I imagine we appreciate these little tricks because it gives us the level of control we want in our modeling projects if you are interested in machine tools or hard Ops there are some links in the description as well they are affiliate links which means that if you use them to purchase any of these add-ons it does help the channel out as well and there are playlist for both of those add-ons in the description as well if there's something that you want to look into but for modeling like this they're not a necessity they're just something that makes life easier have a great day guys

Channel: Artisans of Vaul

Views: 2,624

Keywords: blender hard ops, tutorial, guide, how to, blender 3d, blender, blender tutorial, beginner, pro, order, ordering

Id: nzh0IqoGY44

Length: 15min 49sec (949 seconds)

Published: Mon Jul 08 2024