Learn how to perform Boolean operations on closed splines in 3ds Max.
then you've probably worked with, or at least heard of, Booleans, named after George Boole, the mathematician who developed symbolic logic. Booleans allow us to add, subtract, and find the intersection between shapes. Today we're going to look at shape Booleans. 3ds Max has had 3D Booleans for a long time, And I've imported that logo already and made quite a lot of adjustments to it.
I scaled it up at the sub-object level, I made sure that all the parts were legal for Boolean operations, meaning that they're all closed shapes that lie on the same plane. And, in some cases, I actually had to replace the geometry that came from the Illustrator file with all new geometry, in order to ensure that the Boolean tool worked properly. So I've done all of that in advance. Before we even get to this point we need to have legal shapes for the Boolean.
Let's get in closer in the top view, click in there, and expand that with Alt W, and note that I've also extended the boundaries of some of these shapes, as is appropriate to a Boolean. I'll get in closer on this lower right corner, here, and we can see that one of these shapes overlaps the other. What I'm going to do is I'm going to subtract the area that's enclosed by this orange shape, here. Let's take a look at the original 2D logo for reference.
I've got that as a PNG file. Go to the File menu and choose View Image File, and in the current project scene asset's images you'll find logo reference dot PNG, open that up. And what we're trying to accomplish with our shape Boolean is to subtract the negative space, as represented by the white page or paper, here. Shape Booleans are binary, on and off, and we're not able to do things like differentiate shades of gray here.
In other words, we're not going to be able to do anything with this circle with the shape Booleans. If we did need that circle represented in our final shape, then we would need to use other methods to accomplish that, for example, I could use a 3D Boolean just to cut out that little area so it was shallower than the rest of the extrusion. But for now we're going to ignore that circle and we're just going to concentrate on finding this negative space. We'll start with the outer parallelogram. Select that, and it's the logo object.
Go over to the Create panel, to Shapes, and from the pulldown list choose Compound Shapes, and there's currently only one in there, ShapeBoolean. Click that button and the logo object is converted to a Boolean, and it's listed as one of the operands, here. The shape Boolean looks and acts pretty much exactly like the standard 3D Boolean, so techniques are transferable between those two. What we're going to do here is have nested Booleans, so that we can, for example, add, or sum, or union a whole bunch of objects together and then take that sum and subtract it from another object.
We've only got one operand in our list, here, so let's start adding them. I'm going to get in a little bit closer, here. Click the Add Operands button, and then click on the circle in the center and it disappears, and that's because it's been unioned, or added, to the existing shape. The union operation is an or. It returns a positive value for any area that is enclosed in either one or the other operand.
We want, in this case, to subtract that circle. So with the circle selected in the operands list, click subtract, and now we have a circle nested inside the larger parallelogram. And if we extruded this now, we would see that this area in between those two is solid. Okay, that's a simple subtraction. Now the thing you might think to do next would simply be to subtract these other areas here, this turbine pole and these blades. But if you subtracted them directly, you might not have good results.
In fact, it might actually fail. But what I found works is if we union all of those parts together, or add them all together, and then perform a subtraction on that sum. So that's what we're going to do. To accomplish that, we'll make a sub Boolean in our operands list. Right-click on the circle, and choose Create New Boolean.
an operation of union. We're going to add it with all these other elements here. The Add Operands button is still enabled, so we can go around and select these. Click on the blade, and it's added, but not in the right place. It's added at the top level, or the same level as the logo and the subtract. We want it to be subordinate to the subtract. We want the blade and the circle to be unioned and then that result to be subtracted. So click and hold the mouse down, and drag that Blade 1 directly below the circle.
And it's a little bit difficult to tell, but there are actually two blue lines. Drag it and release on the upper blue line until Blade 1 is subordinate to Subtract. And now we have the result we want. Circle and Blade 1 are being summed, or unioned, and then that sum is being subtracted from the logo. Let's keep going. Add Operands is still enabled. Click on the next blade, Blade 2. Drag it up into the Subtract sub-Boolean.
Click on Blade 3. Once again, drag it into that sub-Boolean. Click on the turbine pole, and once again drag that into the Subtract sub-Boolean. All right, we're doing very well so far. Now we want to add back these little parts here. We have a couple of areas at the center of that turbine that we want to be positive space rather than negative, that's what all of these ovals are for. So let's get a little bit closer.
I'll select the first oval, which is Oval Large, and it's added to the operands. And I do want it to be a union, but I also want it to be subtracted by something else. So we'll make another sub-Boolean here. Right-click on Oval Large, choose Create New Boolean. And right-click and rename it, call it Union 1. Now, that Union 1 has the operand type of Union. Oval Large also is of the type Union.
Add Operands is still enabled. Let's select the other oval, which is the Oval Large Subtract. And it's defaulted to the union type as well. Let's drag it up into the Union 1 sub-Boolean. So it's now subordinate to Union 1. Select it again, and switch it over to the Subtract operation. Now Oval Large Subtract is subtracting from Oval Large, and then that result is being unioned with the logo.
All right, so we'll do the last ones here, and that's Oval Small, and we want it to be a union, once again. Right-click it and Create New Boolean. Right-click it and rename it, call it Union 2. And it's of the type Union. Oval Small is also of the type Union. We're adding our last operand, which is the Oval Small Subtract. Drag it up into Union 2, click it again to make sure it's selected.
And switch its operation over to Subtract. And now we have two crescent shapes, which in our final extrude will be positive, they will actually be solid. Okay, so let's take a look. We can turn off Add Operands. Dialing back, if you go to the four viewport layout with Alt W, I've got a type object here. Select that, go into the Modify panel, and there's an extrude already on it. Right-click that extrude, copy it.
Go to the logo object, and at the top of it, stack, right-click, and paste instanced. And now we've got our 3D logo, made just perfectly with shape Booleans. Let's just review the logic of that just once again. I'll select the logo, go into its Modify stack to Shape Boolean, and once again, we have the logo, which is the outer frame. And that is being added to the end result. Then we're subtracting something, and what are we subtracting? We're subtracting all of these shapes added together.
Circle, Blade 1, Blade 2, Blade 3, and Turbine Pole. All of those are of the type Union. So they're all added together, and then that result is subtracted from the logo. Then we have two more unions down here to add these two little crescent shapes back in. Union 1 is composed of Oval Large, and then a subtracter. Oval Large Subtract removes some volume from Oval Large, and then a result is added at this level, at this Union 1.
And the same goes for Union 2, the same process. Once again we take an oval, we subtract from it, and what's left gets added back to the overall shape. All right, that's a rundown of shape Booleans, and it shows the power of the new Boolean engine in 3ds Max.