Transcript:
Hello, and welcome to Gabot Media. I’m Grant Abbott. And today I’m going to talk about joining objects and detaching objects and some of the pitfalls and difficulties you might come across when doing so this is all part of the quick tips playlist, so check out that playlist and other playlists in the description for more useful videos and courses also. If you like what I do, then try out. My new character course takes you right from beginner to making a fully fledged character in blender as a quick reference. Ctrl J is the keyboard command to join. Make sure you’ve got an active object selected and that’s in object mode. If you want to separate, go into edit mode and press P So here I am in Blender 2.91 currently in beta, and I’m in the startup scene layout. You can see my screencast keys down the bottom here. That will be the only difference to yours, so let’s discuss joining. I’ll keep the default cube where it is, and I’ll add a new one, so shift a to add shift a mesh and then cube. It’s right on top of the old one because my 3d cursor is in the middle of my scene. If I press G to grab now, you can see. I’ve got a new cube just there. Now I’m doing this in object mode, which is the default mode and I can easily select either of these press G to grab and move them independently left. Click G to grab. However, if I go into edit mode with tab or you can change the edit mode just up here, and now I press shift a to add. I only get the mesh menu. I’ve probably got extra ones down here because I’ve got an add-on enabled, but you’ll see these top ones here, but you won’t see all the other things like curves and lights. That’s because we are in edit mode of this mesh, so we can’t add a light to this mesh. We can only add other meshes to this mesh, so I’ll add another cube and that’s put it right on top of the other one again, where my 3d cursor is. I’m going to press G to grab to move that to the side, so we don’t get too confused, but you can see I’m in edit mode with both these cubes, and they are now part of the same object. If I press tab to go into object mode, you can see that now. It selects the whole object together and I press G to grab. They are joined together. I can still select this one separately because that’s a separate object. So whenever you add a mesh in edit mode, it becomes part of that object, so that’s. One way of kind of joining meshes together is to add them in edit mode. Let’s bring this cube over here and I’m going to join these ones like this as well. They don’t have to be on top of each other. In fact, I’ll create a new one shift D to duplicate and move this one over here and I’ll join them all together. Just so you can see it doesn’t make a difference. If they’re overlapping or separate so to join, we select all the objects we want to join together, but be aware that when you select last, that is the active object, so you can see it’s highlighted yellow here. That’s the one they’re all joining too, so if this has any modifiers or anything sort of individual to that mesh, these will kind of adopt that objects properties in order to join. We press ctrl J. You can find that in the object menu under join so control J. And if for any reason that didn’t work, it’s usually because you haven’t selected an active object, so make sure there is one that is highlighted yellow now. If I press G to grab, they are all joined together and that’s obviously in object mode, and if I go into edit mode, I’m going into edit mode of the entire object, which has these separate pieces and we can actually select those separate pieces. If I press Alt a to deselect all and then if I move over one and press l that will kind of select these separate pieces. If I press l over this one, it will select that as well. So you need to press alt a if you want one on its own, so pressing L over this one. I’ve had to press it a couple of times there. If it doesn’t work, just move your mouse really slightly and press l again and it should pick it up now. If I wanted to separate this one out, I make sure it’s selected by pressing L. And then I can press P to separate. You can find that under the mesh menu. Separate with P there’s. Some options here you’ve got by selection. Which is the one I’m going to choose the other useful. One is by loose parts, so that’s anything that is a loose part or as I’ve described as a separate piece of the main object, so any of these separate pieces, they will become new objects. I’ll start with by selection, so I’ll click that one and you can see that it has this orange outline, but I’m still in edit mode for the other shape, so I’m going to tab into object mode, then select this one, and then I can go into edit mode and start editing my shape or in object mode with tab. I can start moving it around independently. I’ll right, click to cancel that movement and I’m going to select this one and notice its center point is right in the middle here, remember? I had this one as my active object. When I joined them all together and that moved the center point of all these into the middle here where this object’s center point was so you can see what I mean. By adopting the properties of the one you join to the active object, so let’s select this one again and go into edit mode and let’s try the by loose parts option, So if I press P to separate and there’s that menu again by loose parts and you can see that these two have become highlighted Orange and this one is now the kind of active object in edit mode. Let’s go back to object mode. I can now select them G to grab and move them around, but see how the center point for these objects is still in that middle there, so when you join objects and then separate them or unjoin them, detach them. They will keep that center point of when they were one big object. Now I’m going to move these all into each other, and I’m going to select them. All make sure you’ve got one active object. So one of them is highlighted yellow and then control J. They’ve all become one object. There’s one important point that I want to make here. If I go into Wireframe mode, you can see that they’re still all overlapping. Let’s go into edit mode as well with tab, and you can see that we’ve got these vertices that are inside our mesh and we call these shapes non-manifold so they don’t have a sort of solid inside. They’re overlapping each other. Now that’s generally kind of considered bad practice, although it is actually used quite often, and you can use this sort of thing within games without any problems, but it’s not optimal, so you have to know what you’re doing when you use it. Also, if you wanted to take this now join shape and let’s say sculpt it. It wouldn’t work in its current state, and if you wanted to send this object out to be 3d printed, it wouldn’t work because of all this overlapping geometry what you would need to do if I go back into object mode and solid mode, you would need to boolean these together, and a Boolean creates a vertex here here and here and it takes away the inside faces, but that’s a video for another time, So if I wanted to separate these, I would go into edit mode and press P either by loose parts or select one using the L key to select those separate loose parts. If I want to join them together, I select them and press Ctrl J. Just make sure that you have one. That’s an active object, always remembering, though, that this is a non-manifold shape and therefore you can’t sculpt it. You can’t 3d print it and it does have overlapping geometry. Okay, so thanks for watching. I hope this helps you out and I’ll see you next time.