From the course: Rhino 5 Essential Training

Troubleshooting solids and Booleans - Rhino Tutorial

From the course: Rhino 5 Essential Training

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Troubleshooting solids and Booleans

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In this video we'll review common situations and problems that occur when working with solids and booleans. I'll also introduce a few new solid editing and creation commands that'll make working with them a little more useful and enjoyable. First up a brand new boolean command. This is on the Solid Tool, tool bar. And it's called Boolean Two Objects. I'll right-click to get that. Just pick the first two, and then it's already launched. We don't have to, we don't have to hit Enter to accept. So, we're just going to click off to the side here. And it's going to cycle through all the various options. If you want to know what those options are, you look up at the command line. Right now, this is b minus a. Here's an inverse intersection. This is a union. It kind of looks the same. Here's a standard intersection. And there's the original a minus b. If you have trouble visualizing what's going to happen with the various Boolean commands. You could try this one, and just cycle through all the options, if that helps. Hit Escape to get out of there. Come over to another similar problem called the co-planar faces. Go ahead and do a straight union, to get this started. So, I'm picking those three objects. Right click when done. And if this is my final goal, this doesn't look quite right. So, unless we count overlapping faces it's not quite as clean. In fact, this may cause problems later if we're going to run fillets along these edges. We really want one plane whenever possible. Here it's just not very cleanly organized. Let's go ahead and do the quick way most people do. They use the Explode to separate faces, so when I click that, it does break them into parts, but everything else too. That's not the usually the best way. So I'm going to Ctrl+z to undo. This should be joined back up now. Now, I'm going to be a little more smart and surgical. So on that same button for Explode, notice there's an Extract Surface option. So I'm going to right click for that. And then we get to pick just the parts we want to remove. So when you're done, you right click or hit Enter. Now I'm going to hit Delete. So, if we click here they're all still connected. So, we haven't exploded. So,that's usually a better way to go. Unless you have a really small, simple object. Now, to get us surface covering this opening up, there's a really nice solid tool called Cap Planer. It's located right here. Cap Planer holes. We can select the object. Right click. That whole opening that is found, it's closed into one simple surface. And I can tell because it's got ISO curves just going in the two directions, one each. That means you couldn't have made it more simpler you've done your job. Now let's take a look at the bottom of this object. We have the same problem as the top we just fixed. But I'll show you a even faster way to fix these problems. And in fact, this next technique will work for multiple areas of overlaps, not just the one plane we fixed. It could be on the top, bottom and all of the sides. That command is right over here. It's called Merge all Co-Planor Faces. I'm going to Right click, select the objects. And now they're all fixed. That might be a even faster way to solve that problem with Booleans. So for our next little demo we're going to explore using some of these commands with solids and surfaces together. So you thought that was impossible but it is. I'm going to subtract this roof from this little building box shape. Let's just start and see what happens. I'm going to use a Standard Difference command. The tip I'm using is first minus seconds equals finals. So the first part I pick in this sequence is the part I want to keep. So that's a good little strategy to remember, if you have trouble remembering which part is which in the order. So we've got the first, right click, and we have the subtraction part, right click. And huh, that's the exact opposite of what I wanted. I'm going to undo and talk about this a little further. So what's happening is, a solid object like this box, it's pretty obvious where's the inside. For surfaces, it's kind of arbitrary. So we can check which direction it thinks is inside versus outside, by using the analyze direction tool. So that's a standard toolbar. Click down here, analyze direction. So those arrows are now pointing at what's called surface normal. The current direction they're pointing, again, is arbitrary. But since it didn't work, we know it needs to be the exact opposite. So we can click on the Flip option up in the Command line, or just click the cursor anywhere on the surface. Notice the arrows are now going the other way. So I'm going to right-click to finish, and I'm going to try the command one more time. Sala tools > Boolean difference, so we pick the part I want to keep first. Right-click, part I want to subtract with. And that's more like it. So remember, there's a, always a direction to every surface. Even though you may not realize it, or think it's too small. It's always a factor. Okay, in the next demo we're going to try something even cooler. We're going to make a solid with a bunch of disconnected surfaces. First up I've got one remaining side open. I'm going to a select these. All these curves, and do a quick surface loft with them. And by default that doesn't look too pretty. That's the straight sections. We're just going to go normal. Hit OK. yeah. Much better. So here's our final goal. Nice, clean, and closed. That might take a lot of work, trimming and selecting, but if we pick all these surfaces individually. Again, some of the reasons I'm working in the perspective view port are to make sure I don't miss anything. It's really easy to miss stuff. We're only looking straight on from one of the ortho views. I believe I got everything. So the command I'm going to show you now is called Create Solid. The requirements are that you have no spaces left open. They fully defined and closed volume. So let's try it. And it worked. Okay, one final tip on working with solids. You want to verify that there's no openings. There's a great little analysis tool. going to select one of these objects I've just created, then go to Analyze > Menu > Mass Properties > Calculate the Volume. So what just happened is I got a series of numbers up here at the top of the command line, and that means it's fully enclosed. It's like, kind of a little hack I've developed. You don't really care what the volume is, you just want to find out there is a volume. However if there's an opening anywhere in this object, you'll get a warning saying, hey, it's not closed we can't calculate it. So use that little trick if you want to verify that it's closed. It's the quickest and easiest way to do it. So these the solid commands and surfaces greatly expands their usefulness. However, you need to be aware of the inside versus outside situation. Which can cause unexpected results, especially on highly edited and complicated objects where the normals can be flipped. When those problems do crop up, start your investigation using the Analyze Direction command, and verify objects are both closed, if they're supposed to be, and that the normal's are pointing outward or the direction you need.

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