Bryce

First, we need two spheres. Here I have 2 shperes, one orange one green for this demonstration. I also gave the first sphere one of the wood materials from the library. You can pick one for yourself after you make your first sphere, but do it now so that material is used for the rest of the objects.

We will use the green sphere as our negative, and the orange one as our positive. Notice that the green sphere is the exact same size as the orange one but is a little higher up along the Y axis (altitude). Its important to get this relationship. To do so, make your first sphere. Select it and hit CTL-D. This duplicates the sphere exactly. Now hold down ALT and drag the new sphere up slightly.

This brings up the Object Attributes window. Take a look around.

Note the boolean settings indicated by the red circle. We will be focusing on these settings in this tutorial. For now, leave everything else alone.

Select the attribute. Uncheck (we will look at this later).

Once you have the settings as they are to the right here, click the to return to the wireframe.

Now select the first sphere and set it to as indicated to the right here.

Once you have the settings as indicated here, click the to return to the wireframe.

Notice how there is no apparent change to the orage sphere but the green sphere is now all dotted. This indicates that the green sphere is set to negative.

There is no obvious difference in the positive setting at this point.

Now, select BOTH spheres. Click the chicklet that appears when you have more than one object selected. This forms a group. Since we have set objects with boolean attributes, Bryce automatically forms a boolean group as indicated by the corner lines of the group bounding box. This is indicated by the yellow circle in the image to the right.

If you DO NOT have these corners, you did something wrong, go back and check your settings for each object and attempt the grouping again.

Here is the resulting render.

Notice how the negative sphere (green) carved out from the positive sphere (orange).

This is the simplest form of a boolean operation, two objects, one operation. But what if we want to have some flat rims on the bowl? Well that will involve 3 objects, two negative, one positive.

What we need is two spheres and a cube. Select the group and click the chicklet to ungroup the original spheres.

Now select the green sphere only. Press CTL-D. This again duplicates the sphere. But we need a cube right?

Click and hold your mouse down on the indicated above...mouse over to the cube object and click it. Your sphere is now a cube and is exactly the same size as the original sphere.

Drag the bottom sizer handle up so that the bottom of the cube is at the middle of the orange sphere. I changed the color of the cube to a dark blue in the shot to the right here.

Now since we duplicated the negative sphere, the cube took on the negative attribute also.

One last detail, you need to make the negative sphere a bit smaller. Select it, grab one of the corner resizer handles and holding ALT down, drag to shrink the sphere down a little.

That done, its time to form the group again. Select the two spheres and cube. Click to group them and verify you have the corner indicators shown by the yellow circle in the image to the right.

If you did things right, you should get the image to the right when you render. If not, go back and verify your settings.

Notice how the cube has cut the positive sphere in half like slicing an orange in half. The negative sphere scooped out the insides.

This represents the next stage in boolean operations, multiple operations. In one group, two objects(negative sphere and cube) are acting upon a third (positive sphere). This of course can be carried to the extreme...hundreds of objects acting on a sinlge (or multiple) objects but the principles demonstrated in this bowl still apply no matter how many objects you are dealing with in a single group.

Now all of the final renders have been shown with one material. What if you wanted to have the material on the inside of the bowl different than what was on the outside and rims? This is an easy thing to do. Remember I had you turn off the "Transfer Material of Negative Boolean" setting for the original negative sphere? Well, its time to turn it back on.

Select your negative sphere (green). Click the to bring up the object attributes dialog. Place a check in the setting as indicated to the right. Click the check to return to the wireframe.

You can select objects without ungrouping your bowl. To select an object inside a group, hold down CTL and click on the object. A menu will appear, select Sphere 2 from the list.

If you were to render now, there would be absolutely no change in your bowl. You need to apply a different material to the negative sphere. For this demonstration, I selected the "Warm Gold" material from the "Simple and Fast" Category. You can choose what ever you like.

Notice now how the the booleans still performed their carving operations. The cube still sliced the sphere in half, the second sphere still carved out the insides.

Whats new is that the negative sphere transferred it's material as a "skin" on the inside of the bowl. If you went back and turned off "Transfer Material of Negative Boolean" on the sphere, it would look like the first render again even though the sphere carried a different mat.

Using this technique of material transfer, you can get some very complicated looking materials happening.