In many situations, you’ll want your 3D model to be a hollow, rather than solid mass. The Shell tool lets you convert a solid into a shell. Here’s an example of how it might be used.
1. Choose the Shell tool from the Solids Editing toolbar.
2. Click the model. The entire model is highlighted, AutoCAD assumes you want to shell the entire object with a few faces completely removed. The Remove faces or [Undo/Add/ALL]: prompt appears and you see the object selection cursor indicating that you can select objects for.removal.
3. . Click the top-front comer of the solid, as shown in Figure 18.40, to remove the two surfaces that adjoin that edge.
4. Press ↵ to finish your selection.
5. At the Enter the shell offset di stance: prompt, enter. The solid becomes a shell with a 0.1 wall thickness.
6. After studying the results of the Shell tool, type to undo the shell operationin preparation for the next exercise.
The shell thickness is added to the outside surface of the solid, so when you’re constructing your solid with the intention of creating a shell, you need to take this into account
Copying Faces and Edges
There may be times when you want to create a copy of a surface of a solid to analyze its area or to produce another part that mates to that surface. The Copy Faces’ tool creates a copy of any surface on your model. The copy it produces is a typeof ‘object called a region. You’ll learn more about ‘regions later in this chapter. Right now, let’s see how the Copy Faces tool works.
1. Click the Copy Faces tool on the Solids Editing toolbar.
2. Click the front-top edge of the model, the same one in the Shell exercise. Two surfaces are highlighted.
3. Press .J to finish your selection.
4. Click a base point for the copy, then enter @10<315.
5. Choose View >- Zoom >- Extents or type Z.J E.J to view the entire drawing. The copied surfaces appear to the right of the solid.
The copies of the surfaces are opaque and can hide objects behind them when You perform a hidden-line removal (View >- Hide).
Another tool that is similar to Copy Faces is Copy Edges. It works in a similar way, but instead of selecting surfaces as in step 2, you select all the edges you want to make copies of. The result is a series of simple lines representing the edges of your model. This tool can be useful if you want to convert a solid into a.set of 3D Faces. The Copy Edges tool-will create a framework onto which you can add 3D Faces
usinq the Command Line for Solids Editing
The Solids Editing tools are actually options ofe single AutoCAD command called Solidedit. If you prefer to use the keyboard, here are some tips on using the Solidedit command. When you first enter Solidedi U at the command prompt, you see the following prompt:
Adding Surface Features
You’ll start by inserting an object that will be the source of the imprint. Then you will imprint the main solid model with the object’s profile
i. Choose Insert» Block.
2. In the Insert dialog box, click Browse, then locate the Impri nt. dwgfile in the directory and select it.
3. In the Insert dialog box, make sure that the Explode option is checked and remove the checkmark for the Specify On-Screen check box in the Insertion Point group.
4. .Click OK. The block appears in the middle of the solid.
5. Click the Imprint tool.
6. Click the main solid model.
7. Click the imported solid.
8. At the Delete the source object <N>: prompt, enter Y.
You now have an outline of the intersection between the two solids imprinted on the top surface of your model. To help the imprint stand out, try the following steps to change its color.
1. Click the Color Faces tool on the Solid Editing toolbar.
2. Click the imprint from the last exercise. The imprint and the entire top surface is highlighted.
3. At the Select faces or [Undo/Remove/ALL]: prompt, type R.J, then click the outer edge of the top surface to remove it from the selection set.
4. Press 1. The Select Color dialog box appears.
5. Click the red color sample at the top of the dialog box, then click OK The imprint is now red.
6. Press.J three times to exit the command.
7. To see the full effect of the Color Faces tool, choose View >Shade >Flat Shade. The imprint appears as a solid red area.
If you want to remove an imprint from a surface, use the Clean tool on the Solids / Editing toolbar. Click the Clean tool, then click the imprint you want to remove. If the imprint has a color, then the color will “bleed” out to the surface where the imprint was placed.