23.5 Making the Cutout

A full isometric view of the object is now ready. But, in order to demonstrate some additional techniques, I decided to create a cutout of the object showing its two perpendicular cross-sections.

Since everything we have done so far is snapped to the grid, adding the cutout shape is very easy. Switch to the Pen tool (14.1 The Pen Tool) and click near the corners of the left side of the cross-section. Then, starting with pressed to create a second subpath of the same path, click through for the right side:

Figure 23-10. Adding the cutout shape

Often, cutouts in technical drawings are filled with a pattern that symbolizes the material of the object. Plain stripes are used for metals, and we can indicate that our object is metallic by using one of the preset patterns. Open the Fill and Stroke dialog (8.1.1 Paint), click the Pattern button on the Fill tab, and choose the Stripes 1:8 pattern. The only problem with this pattern is that it shows black stripes on a transparent background, but we need black stripes on a white background. Just duplicate the shape, paint it white, and move the white copy under the striped one in the z-order.

Figure 23-11. Painting the stripes

Now we need to remove the parts of the object in front of the cutout. Drag around and delete the frontmost rounding cylinder. Using rectangle resize handles, contract the top and left sides of the box to snap them to the edges of the cutout. As for the rest of the objects (the top of the box and the top ellipse of the cylinder), we need to actually cut them.

Again using the Pen tool, snap-draw a triangle and subtract this triangle from the shape (select both and press , 12.2 Boolean Operations), as shown in Figure 23-12.

Figure 23-12. Cutting out unnecessary pieces

Finally, create the inside of the hole visible through the cutout: Duplicate the cylinder shape, scale it down (), and step it down in the z-order so it’s under the cutout shape and the hole ellipse; this will be the inner surface of the hole. Using the Node tool, select and pull down the bottom nodes of that shape. Then, duplicate the hole ellipse, paint it white, and move it down to represent the bottom edge of the hole. Select the ellipse at the top of the hole and copy it to the clipboard (); then select the inner surface cylinder and paste the style () to spread the hole’s horizontal gradient to the entire inner surface of the hole:

Figure 23-13. Creating the inner surface of the hole