Building the cabinet with polygons and Booleans
Video: Building the cabinet with polygons and BooleansThe first step in our process of creating the speaker cabinet is to start with the speaker cabinet itself. I'm going to add a cube to the scene. And this cube is going to be the foundation for our whole model. Before I make it editable and start chopping on it with the Knife tool, I want to do a couple of things. First thing I want to do is change the aspect ratio of it so that it more closely matches our cabinet. So let's take the Size X and make it about 530 units. And I'm hitting the Tab key, change the Y to be 700, and then I'm going to change the Z to be 270.
- Modeling workflow overview
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CINEMA 4D Essentials with Rob Garrott is a graduated introduction to this complex 3D modeling, rendering, and animation program, which breaks down into installments that can be completed within 2 hours. This installment covers the basics of the 3D modeling toolkit: splines and polygons. Rob reveals the components behind polygonal-modeling (points, edges, and polygons) and how to manipulate them with the tools in CINEMA 4D. He then walks through splines, an alternative to polygons that uses curves to create 3D geometry. The final chapter shows how to combine these techniques by creating a model of a speaker system.
- Understanding points, edges, and polygons
- Working with the Knife, Extrude, and Bridge tools
- Connecting splines
- Rounding corners
- Extruding paths from Illustrator
- Reviewing the polygon and spline modeling workflow
- Working with NURBs
Building the cabinet with polygons and Booleans
The first step in our process of creating the speaker cabinet is to start with the speaker cabinet itself. I'm going to add a cube to the scene. And this cube is going to be the foundation for our whole model. Before I make it editable and start chopping on it with the Knife tool, I want to do a couple of things. First thing I want to do is change the aspect ratio of it so that it more closely matches our cabinet. So let's take the Size X and make it about 530 units. And I'm hitting the Tab key, change the Y to be 700, and then I'm going to change the Z to be 270.
That's going to give us the right shape for our speaker cabinet and depth as well. Now, I want to change the filleting on the speaker. Let's back out just a bit. A cube by default has these very sharp defined edges. They don't pick up highlights when you shine a light on them. And objects in the real world that have corners on them and edges have little transitions from the face to the side that pick up light, and that really does a lot to make an object look more real. So let's change the filleting on this cabinet and I'm going to turn it on first. Now, the default values are too round in this case.
So let's start off by making the Fillet Radius about 4 and the Fillet Subdivision, 2. And that's going to give us a really nice transition. And you can see it's already picking up highlights just from the Editor View Lighting that we're seeing here. Next, we want to create the Boolean that's going to generate the opening in the front of the speaker cabinet so the woofer can poke out. And a Boolean object is a mathematical way of adding and subtracting objects. It's not something I normally use when I'm modeling, unless I know that the object itself isn't going to be deforming.
If I were trying to make a dancing speaker cabinet, I wouldn't use Boolean object. But this speaker cabinet is really just going to be sitting there so I don't have to worry about weird deformations and Boolean objects make very strange geometry sometimes, and so I try to avoid them when I'm modeling. But this is an instance where it's going to work out just fine. A Boolean object exists under the modeling Objects and let's add it to the scene. The way the Boolean works is that it has a logic to it. The Boolean Type defines that logic and we've got A subtract B as the default, and this is exactly what we need. You can see there are other options here.
The A subtract B indicates that there is going to be two objects underneath here. The Cube is going to be the A object and we need a B object. The B is going to be a cylinder that's going to cut a round opening in the front. So let's add a Cylinder to the scene, and let's change the Orientation to be Z, or +Z or -Z, it doesn't matter in this case. And then I'm going to make the Radius to be 200 units and that's about the same diameter as the woofer we're going to be creating. Now, our Cylinder is sitting right in the middle of our cabinet, so let's drag it on its Z-axis and move it out a little bit.
And I'm going to move it down into position. The woofer on this cabinet is going to take up about the lower two-thirds and let's navigate over a little bit and zoom in just a little bit more. You can see that it's about in the right space. So the way the Boolean object works is I'm going to take the Cube and put it in the A position. I'll take the Cylinder and drop it down into the B position and instantly I get a hole. Now, you notice this is all live. If I change the cylinder into the A position, you'll see that it cuts the cube out of the cylinder.
But that's not what we want so I can always just switch it back. I'll put the Cube into the A position. Remember the Boolean always work in an A-B. Now what I'll do is move the Cylinder back into position so it's sticking just a little bit out of the front of the cube. And I don't want to go too far. I want to have it sticking just out of the face. That gives us just what we want and now we've got a nice deep opening for our subwoofer. Before we go any further, let's save our progress. So let's go to the exercise files folder in the modeling subfolder and let's call this speaker working.c4d and then I'll just hit Save.
Now that we've got our file saved, we can move on with the modeling process. Now, the Boolean makes very strange geometry but we can't see that geometry even if we go into Polygon mode. What we need to do is to change our Display Options and this setting in the Display Options is going to let us see the geometry of our objects. Under the Display menu, we're going to go to Gouraud Shading with Lines. Now, the default is Gouraud Shading without Lines, but we're going to turn on Lines. And you can see that now our object has lines on the surface and you really get a feel for the geometry of the object.
As you can see the Boolean object is creating these very long triangles on the front of our object and that's not a very optimum arrangement of polygons. We're going to be needing to create some slices up in the top area of this cabinet where our tweeter is going to go and this large polygon on the front is going to make that process really difficult. So to correct this problem, I can't eliminate them completely but I can minimize them. The way I'm going to do that is by using the Knife tool. Now before I can use the Knife tool, I'm going to select the cube and make it editable.
Now that it's editable, I can switch over to Point mode. Now my points are very large here and that's because I changed a display preference in one of the earlier movies in this chapter. In order to see large points, you're going to need to change that same display preference. The way I did that was by going to the Options menu and going to Configure All. And we're going to go to Viewport settings and under where it says Point Handle Size and Select Point Size, we're going to change those values to 9. And that's going to give you the exact same size points that I've got here.
Now we're ready to do our slicing. So let's select the cube and then right-click anywhere in the Editor window to get the Knife tool. The Knife tool mode by default is set to Line. We want to change that mode to Loop. Now that I'm in Loop mode I can come in here and make a cut. Now, the normal way for the Knife tool to work in Loop mode is to draw a line around the object. Now, I'm having an issue with my screen capture software that's causing the line not to draw, but you should be seeing a line traveling all the way around your object. In this window you can see that these four dots represent where that line would be if it were traveling all the way around my object.
So when I cut this cube with the Knife tool, it's going to change how the Boolean is behaving. So let's make a cut with a Knife tool right about here just above where the cylinder is cutting into the cube. Now, I don't want it to snap down on top of that cylinder. Over here in the left-hand side of the interface, you'll notice that this magnet is activated. That's the Snap settings. When I grab the Knife tool before, it automatically turned on the Snapping options for me, and I'm going to turn that off by clicking on the magnet. Now I can make my cut without having to worry about that snapping.
Before I do that, I want to make sure that I'm not cutting through the cylinder, I want to cut just above it. Okay, that's looking pretty good. I'm going to make a cut right about there. And as you can see, that totally changes how the Boolean is behaving. Now I made my cut just a little bit too low. That's what's causing these triangles here. I can fix that by moving the edges up. So let's undo that and then make our cut just a little bit higher up on the cube. And you can see that when I make this cut, it isolates the geometry to just this area, and that really changes the way the Boolean object behaves and that's just what I need.
Now I need to make just a couple more cuts up in the top area for the tweeter opening. I'm going to make a cut right about here and then right about here. And then I need to make some cuts along the X-axis for the tweeter opening as well. So the first cut I want to make is going to be right in the center of the cabinet. Now, I could eyeball it but an easier way to do it is to use just a little bit of math. So I'll just make a cut anywhere and don't worry about any geometry that it gets created. We're going to fix that. Now what I want to do is to select all the points that resulted from that cut.
So let's switch over to the Rectangular Selection tool and then make sure to uncheck Only Select Visible Elements, that's very important. That's going to allow me to select objects all the way through. Now when I middle mouse click to get to the Four-way View, I can draw a selection around those points in the front view. And then when I go back to the Perspective View and orbit around, you can see that I've selected all the points, all the way through to my object and that's really important. Now I can use the awesome power of the Coordinate Manager to change where those points show up. Now, the Coordinate Manager is used for changing where your object is in space, but it can also be used for manipulating the elements that make up your object.
And it's very important in the modeling process. The first thing I want to do is change the pull-down here from Object Relative to World. And then I want to change where they are in the X-axis. Right now they're showing up at -50 on the X-axis, let's change that to zero, and you'll see that those points are going to jump right to the center of the cube. Now I can make two more cuts for the opening of that object. So let's switch to the Perspective View. I'm going to hit the letter K for the Knife tool. I'm going to make two cuts along the X-axis; one about here and then one more about here.
Now, you notice I didn't worry about where I made them, that's because I'm going to use a little bit of math again to correct their position. So let's select those points again. Let's switch to The Four-way View and then we'll go back to the Selection tool. I can just hit the Spacebar, that's going to get me right back to my Rectangular Selection. Now I can draw a selection around both of those loops of points. Now you can hold down the Shift key when you grab the second ring of points. And as I orbit around here, you can see that I've selected all the points all the way through the object. Now what I want to do is change both the position and size of these and I'm going to use the Coordinate Manager to do that.
If I go in the Coordinate Manager and look at the X-axis position, you can see that they're not lined up with Y. Let's switch to the Front view. I'll middle mouse click in the front view. You could see that the axis point is just a little bit offset from Y. If I just drag it over here, you can see that that X value changes down in the Coordinate Manager. So now, if I change that value to be zero, I know that these two rings of points are going to be lined up exactly on the Y-axis so that they are completely centered along this axis here. Now what I want to do is create the size of the opening using the Coordinate Manager and I want to create a nice big opening for my tweeter, because I got a nice big tweeter, it's going to go right in there.
So let's hit T on the keyboard to get to the Scale tool and I'll click on the X-axis only and I just drag to the right to scale that up. Now I can do the exact same thing vertically by switching back to the Selection tool and drawing a rectangle around these two loops of points. And then using the Scale tool, I can scale that opening up just on the Y-axis. I can also move it down just a bit, I'll hit E on the keyboard to get the Move tool and then drag that down. That way, the tweeter is not too close to the top of the cabinet.
This is the space that the tweeter is going to occupy here, this little rectangle. Now, I'm not concerned about this opening here or this opening here. I'm only concerned about the opening in the middle. But I think that's a pretty good size for the tweeter compared to the woofer down below it. So let's middle mouse click to get back to the Perspective View and I think we're doing pretty good. The last thing I want to do is to delete these polygons on the front of the cabinet. So let's switch over to Polygon mode, then we'll go to Live Selection tool and grab just those two polygons and hit Delete.
Now I've got an opening for my tweeter. And you're probably asking yourself a very important question at this moment, Rob, how come you didn't just use another Boolean object for the tweeter? Well the answer is that because this is going to be a rectangular opening, it's much easier and cleaner to do these cuts with the Knife tool and just delete the polygons than use a Boolean. The Boolean object is going to give you a very ugly geometry. And we've already got one Boolean in the model already and I didn't want to compound things for this model by using a second Boolean object. So that's the first step in the process for creating the cabinet on our speaker.
Now we can move on to modeling the tweeter.
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