Understanding Rhino Entities - Rhino Tutorial

- [Instructor] Let's take a tour of the entities in the Rhino universe. There are three basic ones we need to be concerned about. The curve, the surface, and the solid. And it's very easy to keep these clear if you look at the menu and see how they're organized one after the other. Here's all the curve commands, surface, and solids. Kind of in a logical organization there one after the other. Let's now zoom in and talk about some specifics. We've actually got another entity I didn't mention. It's called the point. It's not used so much for modeling, more as a reference or a marker. Curves can be either open or closed. So this is pretty obvious, it encloses space. But if you're not sure, you can highlight it. Over on Properties, it will tell you that there's no gaps and therefore it's closed. Now one cool thing about single entities with curves is you can turn on the control points over here on the main menu, and continue editing these guys. That's gonna be really important. So curves can be straight or wiggly. They can be open or closed. Surfaces can be simple or have openings, be untrimmed or trimmed, but since they are a single entity, you can highlight them and turn on control points and do further edits. Pretty cool. I'm gonna turn those off by hitting the escape and we'll go next to solids. Now here's a classic solid, your basic cylinder. We highlight it and we can verify that it's closed because over on the Properties, it tells us closed and solid. But Rhino also allows kind of an in-between stage, almost of a poly-surface. It's the cool thing about it having openings is we can use solid commands along the edges and many other operations. So as along as you have more than one surface joined up, two or more, you can use solid commands. They don't have to be 100% closed. They can be closed and they can be open, but they would still use solid commands. Finally we've got kind of a special case here. This is a single surface, but it is still closed. How does it do that? A lot of depth formation. So we can click on this sphere here. And since it's a single surface as we've already talked about, we can turn control points on and continue to do some tweaks and edits. Not the way I recommend so we're just gonna leave it at that and undo it. Escape twice to get back out. Now let's move on to multiple entities. I turn this layer on here. Zoom around. The key with making multiple entities is the endpoints need to be shared. Then you can use the join command. We'll do that just in a minute. So this would be a poly-curve that is open. Here is a poly-curve that is closed. And this one's just kind of an interesting mix of some straight segments and some more freeform curves. Those are all poly-curves. Moving along to surfaces, we've got this interesting character here. It's got straight sections, curved sections, and other entities. So the key here is as long as edges are shared, they are allowed to join up. And we'll go ahead and prove how this works. On this example here, we've got two planes and they were built sharing an edge so we should be able to join them together. I'm going to select one, shift select the next guy. Assuming these share an edge, we should be able to hit this little puzzle piece to join or control j, PC, command j for Mac. They should highlight and be a single open poly-surface. That just means more than two surfaces. I'm gonna stop for a moment and clarify these are joined. That's completely different than a group. A group is just kind of temporary, it's a collection, and it does not even care if edges are shared. So that's a very common beginner mistake. They'll pick up whole series of curves or surfaces, group them together and consider their work done which it's not. You've got to make sure end points for curves or edges for surfaces are touching and shared before you can join them. So these entities are the foundation of all Rhino modeling. It's important to understand the relationship, but also the importance of creating curves first. Due to reasons we get into later, you should almost always start your design geometry with these curves, then build them into surfaces, and so on from there. You'll see me use this strategy exclusively throughout the course.