Join Chris Reilly for an in-depth discussion in this video Modeling the base profile, part of Rhino for Mac Essential Training.
- [Instructor] In the last video we set up our file with correct units and grid spacing, and we made a new Grasshopper definition that at the moment just has one component and that is this Rectangle component. Before we get started here I'm just gonna get started here I'm just gonna do a little bit of rearranging on my windows here. So I'm gonna snap Grasshopper to one side and Rhino to the other side and I'll turn off my sidebars in Rhino. And this will make it a little bit easier to see what's going on. So again, when we're working in Grasshopper we'll be doing edits on the Grasshopper definition over here in the Grasshopper window and those will cascade into Rhino and start making geometry.
So the goal of this video is to recreate the profile of the wooden base of our musical instrument. So if you remember from the last chapter we made that by making a rectangle that was about seven inches long by about one and 1/2 inches wide, and then filleting the corners of that rectangle to kind of round over the ends. So that's kind of the starting point of how I'm thinking to work through Grasshopper is to make a Rectangle, set the width kind of long, set the height a little bit shorter, and then work in some fillets to round out the corners.
So we have this Rectangle component here, I have the X input, so that's the size in the X direction, I have the Y input, that's the size in the Y direction, I have the base plane that the Rectangle is landing on. Right now that happens to be the world XY construction plane, same as what we see from the Top viewport. And I have an option for a fillet Radius. So what I like to do is give myself the option of a variable size rectangle. So I'd like to connect some Number Sliders to the X and the Y inputs of the Rectangle, and I can get to the Number Slider under the Params component tab, under Input, so I'll just grab this Number Slider here.
Whoops, and where did that end up? Way over here. Just one of these little buggy things that we're gonna have to deal with until Grasshopper gets released in the official version of Rhino. But here's our Number Slider. So I'm gonna connect that to the X input. Now you can see over here in the Rhino window the width of my rectangle is changing as I adjust that slider. So let's double-click on the Number Slider here and we'll set up some additional parameters.
First of all I'm gonna give this a Name, so this is Base Length, and I want real numbers here, not integers, and let's look at the Range. So obviously I want this to be not zero, but maybe, one is the minimum, so I'll double-click on the Minimum, type in one, commit. And the Max, maybe let's say up to 15, just in case we wanted to try a base that was very long. OK.
That's our Base Length, and now you can see we could slide that Rectangle back and forth, we get the size. And the little grid here we see is the base plane input from the Rectangle and we can hide that later on. I wanna do a second Number Slider for the height of the Rectangle, so I'm just going to select my Base Length Number Slider, do Edit, Copy, and Edit, Paste. And this one goes into the Y component. Let's zoom out a little bit here.
And so that sets the base height. And I could adjust the Min and Max here if I really wanted to, I'm gonna leave this up to 15. I don't think that would ever be a sensible size for this musical instrument. It's probably gonna be maybe something between like one and four, but it might be nice to have the option later on. So I can see I'm generating a Rectangle here that's 11.684 inches wide, and 3.092 inches high, and that's great. And the last thing I need to do is to add some fillets to round over those corners of the Rectangle.
So the Rectangle component has a built-in fillet input. In this case we're not gonna use that, we're gonna use a separate fillet component and that has to do with some steps that we'll take later on. So I'm gonna go into the Curve component tab, down to Utilities, and I wanna grab this style of Fillet, so Fillet the sharp corners of a curve. Way over there, let's get that over here, great.
So Fillet is asking for our Curve, so that's gonna be this Rectangle output from the Rectangle component. And we also need to specify a Radius to actually make the Fillet. And for that I'm gonna need another Number Slider, and again, I'll just copy one of these that I already have, so I'll do Command + C, Command + V. And this one now will be our Fillet Radius. Then we can go ahead and disable the Preview on that Rectangle component, so I'll right-click and uncheck Preview, so that you can see that turns off the base plane and the actual Rectangle, and then what we should see is this Fillet component here.
Now you might notice some strange things happening. So you can see as I dial down the Fillet Radius you can see there it's actually changing and updating, but as I go towards the right end of the slider nothing is happening. And what's happening here is the Fillet Radius is being capped by the Base Height component. So I'm just gonna go ahead and adjust one more time the Min and the Max here. So the Min I would like to be something very, very small, so like .001, and then the Max is going to be capped by the Base Height, so let's maybe say something more reasonable like five, even though I don't think, I don't know if we would ever get that wide, but that's a pretty good range, and let's go ahead and just click OK here.
So now that makes a little bit more sense in terms of the scope of the numbers that we're dealing with. And you can see that's gonna update as we change the Base height, so you can see it's not gonna quite max out yet, but here that Fillet Radius is maxed out. And let's set that to a little bit more reasonable scale there. So we've gone ahead and made this Grasshopper definition that defines the profile curve for the wooden base of our musical instrument, and we're ready to move onto doing some things like through holes and modeling out the rest of the parts.
The last step I wanna do here is just save out this Grasshopper definition, so I'm gonna say File, Save As, and I'll save this to my exercise files as 05 02 BaseProfile. And you should have access to that as long as you have access to the exercise files for this course. And now we're ready to move onto further steps modeling through Grasshopper.
- Installing Rhino for Mac
- Preparing a design
- Modeling metal parts
- Importing models
- Modeling parametrically with Grasshopper
- Extruding objects
- Modeling curves, surfaces, and solids
- Creating diagrams, 2D drawings, and layouts
- Preparing for fabrication: cutting and 3D printing