Join Dave Schultze for an in-depth discussion in this video Save the day with a superhero cape, part of Rhino: Tips, Tricks & Techniques.
- [Instructor] Our next mission is to build a superhero cape for our penguin friend. We'll try to make this cape from a small number of curves and then loft in a few simple steps. Let's zoom in on this cape. This is our end result or our goal. A few things I'd like to share with you. These are really important tips. We're going to try to work in place, which means the final destination, right where the penguin needs the cape. That means if other stuff is in the way, we should turn those layers off and avoid building stuff off to the side and then dragging it into the correct position.
So let's just turn the penguin layer off. I'm also going to switch to shaded view so we can talk about this. It's a simple plane that I've made on the access layer, and I'm going to use it to get the construction plane up to this level. Right now, it's down at Z equals zero, and as you saw, we want to put the cape right here where needed on the penguin's neck. So, let's get the construction plane up. We're going to use the command called CPlane, and then snap to an object, so that's why I've selected and built this plane already.
So as soon as I pick it, the construction plane, you noticed, jumps right up. Now, all geometry made will be right on this level. The next step is to draw a straight line. I'm going to go to Curve, Line, Single Line. This may seem weird, but hang on. I like this command because I can use the Both Sides. I'm going to snap to the midpoint here, so that means we need to turn that on and then center should be off. So I'm going to start here and this is just to keep things organized, the Both Sides goes out equal distances both directions.
I'm also going to move this a little bit away from the plane so it's easier to see. However, this is not very organic. Let's go ahead and select it and hit F10 to turn on the control points, and that looks like something that just won't work. Not a problem. I'm going to go ahead and turn the control points off, F11. We're going to rebuild this. Edit, Rebuild, Select Curve, right-click, and I'm going to change it from a very simple straight degree one line to a degree three, which means it's very smooth and organic.
We'll be using that for the loft coming up. The point count, it was at two. We're going to change that to 11, and hit okay. Now, it looks the same, so let's just double-check this by clicking the line, hitting F10 one more time and there's all the extra control points. Now, there's a reason I picked two more points than needed. You'll notice that they're nice and equally spaced, but they're half-spaced at the ends, so I can just pick the endpoints and delete on both sides.
So now I have nine control points, nicely, equally spaced across there, and I can start editing and moving these. However, I'm going to leave this line exactly where it is. F11 to turn those control points off one more time. I'm going to go ahead and copy this, Control + C, then paste with the Control + V, and move the next line a ways away. Okay, since this is a degree three curve, that is very organic, I can again turn the control points back on with F10 and start some edits.
I'm going to pick this second-to-last point and then the middle three. I've got my page up set to nudge on the Z direction, so as I bump upwards, nudging, I get some nice, organic deformation here. So there I go. There is kind of the profile I'd like to use, however, it is kind of small, so let's go ahead and again, we're going to turn the control points off. This happens a lot in this process. I'm going to use the 3D scale over here in the main tool bar.
I do want to click from the midpoint. Quad is okay, but I want to make sure. Just turn that off and make sure I'm in the midpoint. So, our scaling is kind of simpler than it looks. You just want to pick a starting point anywhere, and as you get farther and farther away, it's a larger scale. If you get closer in, it's a smaller scale. So it's not that critical. So I'm just going to eyeball this. There's the very first curve. Let's go ahead and copy and paste again.
I'm going to drag one over here. This'll be the biggest one. After we scale it, copy / paste that, and there is our final curve. A few more tweaks here to do. I think this will be easier if we jump to other viewports, so I'm going to pick the very first one we made there, and move it up. That's going to be a lot easier here in the right side viewport. The third curve is the biggest one and we haven't scaled it yet, so let's go ahead and do that. That is the scale 3D, and you want to snap to the midpoint, and I can type in a number like two that would double the size or I could continue just picking a reference point, dragging away to get a larger endpoint.
That looks about right. Let's move that guy down a bit, and then finally, we've got the end profile. That needs to be a bit bigger. Not quite as big as the third one, but somewhere kind of in between, so we'll try that. Same scale. We can now start to see how the loft will happen. Let's double-check this from the perspective here. So, here's our starting curve. Even though I drew it straight, it's got the same number of control points, and it's going to flow up, get larger flow down, and then finally end up here at the very last curve.
I think we're ready to go. I'm going to double-click on Perspective. I'm going to select all of these curves by holding down Shift as I go through, and we access the loft command from Surface, Loft, right there at the top. But before I accept it, you might want to check it out. That looks really cool and the key here, though, whatever tweaking you may want to do or continue to change, this is all kept really simple, because the same number of control points. Let's just accept that result here.
Hit Okay. This might be hard to see. Here's some of the options. We'll go Okay, and complete the command. And finally, if we're going to prototype this, we want to give this single surface here a little bit of thickness. So let's go up to the surface menu, select Offset Surface. We're going to pick the cape right there, right-click. You always have options to go in two directions for any surface. In this case, we're going to go up. I'm going to select a distance of three. I don't want this to be too thick.
And then, if you want that edge, you do have to put Solid equals Yes every time. It always defaults to No. Right-click to accept. So there's the thickness. One last thing I would like to do if you want to have a corner detail here. I always save these for the end. Because this surface is flowing in two directions, I can't pre-filletize it or put fillets on those curves, because they would get distorted. So I let things kind of end up with sharp edges, like this, and at the very last step, I'll go ahead and throw a fillet on there.
Let's do that now. This is a polysurface over solids. This is all joined together. Solid, Fillet Edge, Fillet Edge. I'm going to modify the default one to about 10, and then just pick both of these little square edges. Looks like it might not fit, so I'm just going to right-click to go ahead and try it. As long as our surface geometry started off clean, you should have no problems. And, finally, to enjoy our work here, we always like to select the object and turn off those iso curves, because they can get a bit busy.
Turn those off and it does look spectacular. If you do want your construction plane back to its original position, another way to move it is go to CPlanes here on the tool bar. This is the world top or kind of the master default location. You can also turn the penguin layer back on. Like most organic shapes, the goal is always to use the minimum number of curves, but also keep the curves simple, too. Simple curves just means always using the bare minimum number of control points.
So follow these rules and your geometry can avoid the potential complexity that may result in problems.
- Building and detailing a space helmet
- Making a flexible duct
- Building details on round pipes
- Modeling organic objects
- Using the SrfSeam command to move seams out of your way