Chapter 6 Creating Extruded and Revolved Objects

From ShadeCamp

Using the solid tool enables you to easily solidify created line objects or disk. In this chapter, you will learn the use of solid tool and later create some shapes.

Extruding

Select a line object or disk to be extruded, and specify the direction and distance to create an extruded object.

1. Choose Extrude from the solid tool and drag from the starting point to the endpoint of the desired extrusion.

A straight rubber-band line connecting the point where the mouse button was pressed and the 3D cursor appears, serving as a visual aid in specifying the direction and distance of the extrusion.

2. The point where the mouse button is released is entered as the endpoint of the extrusion, and an extruded object is created. It is indicated with the name Extruded (object name) in the Browser window.

If you select a part and Extrude it, all line objects and disks included in the part change into extruded objects. If the part contains extruded or revolved objects, the original extrusions and revolutions are cancelled, and those objects are re-created as new extruded objects. When you select the Enter Modify Mode in the Modify tool with the extruded object selected, a line object which will then be modified into an extruded object is edited.

Editing the line object will change the section and the line object is automatically returned to the extruded object. Displaying the Object Info in the Aggregate window with the extruded object selected will make it possible for you to verify the values of the position and extruded distance of the object in the Object Info window and edit by entering new values.

Revolving

Select a line object or disk to be revolved, and specify the rotation axis to create a revolved object.

1. Choose Revolve from the solid tool and drag to specify the desired rotation axis. A straight rubber-band line connecting the point where the mouse button was pressed and the 3D cursor appears, serving as a visual aid in specifying the rotation axis.

2. The point where the mouse button is released is entered as the endpoint of the rotation axis, and a revolved object is created. It is indicated with the name Revolved (object name) in the Browser window.

If you select an extruded or revolved object and Revolve it, the original extrusion or revolution is cancelled, and the object is re-created as a new revolved object. If you select a part and Revolve it using Revolve in the solid tool, all line objects and disks included in the part change into revolved objects. If the part contains extruded or revolved objects, the original extrusions and revolutions are cancelled, and those objects are re-created as new revolved objects.

Image of the revolved object shown above rotated along a different axis again.

When you select Enter Modify Mode in the Modify tool with the revolved object selected, a line object which will then be modified into a revolved object is edited.

Editing the line object will change the section and the line object is automatically returned to the revolved object. And, displaying the Object Info in the Aggregate window with the revolved object selected will make it possible for you to verify the values of the position of the object, the radius, and the Begin/End angles in the Object Info window, and edit numerically by entering new values.

Clear

When Clear is selected in the solid tool, the extrusions and revolutions of all selected objects are cancelled, and the objects are reset to their original line objects and disks.

Creating a Scene Using Solids

Let’s try making a table and chair using revolved and extruded objects. To create them, we will use the solid tool in the Toolbox on line objects and disks.

1. Create a new file by selecting New in the File menu.

2. Select the Figure Controller from the View menu and switch on the Grid checkbox.

A grid appears in the Figure window.

3. Move the mouse pointer in the Front view and make sure that the Z coordinate value (as shown in the Figure Controller) is set to 0. (To set the Z coordinate to 0, put the pointer in the Top view, move it until the Z value is zero, and click. Then move the pointer back to the Front view).

Move the mouse pointer to the Front view

Now we will create a line object (whose Z coordinate value is 0) in the Front view.

4. Select Open Line from the Create tool in the Toolbox to create a line object in the Front view as shown in the figure below.

Although the object does not have to be identical, the end points of the line object should be aligned on the Y axis.

The solid grid lines in the Figure window indicate the 0 axes of the X, Y, and Z coordinate values.

To create an object with end points aligned, the large cursor is useful. To display the large cursor, press the A key.

The figure shown below shows a large cursor while clicking at the last anchor point when creating an object. To regain the original (small) cursor, press the A key again.

You can also switch the large cursor on and off using the Large cursor checkbox in the Control Bar.

Modeling a Chair

1. Select Revolve from the solid tool in the Toolbox.

2. To set the axis of revolution, drag the cursor from A to B in the Front view.

A Revolved shape is created. The description “Open Line” changes to “Revolved Open Line” in the Browser window.

The length to which the axis of revolution is dragged when creating a revolved object has no effect on the outcome. The position of the axis where the dragging starts and its direction are the two vital conditions in the creation of a revolved object.

Advice on Creating a Revolved Object

There are some points you should be aware of when creating a revolved object.

For instance, if the center of the axis of revolution of the object that you have created earlier is at the point shown in the figure below (in the Top view), you can create a revolved object.

The revolved object is created around the center set earlier.

If an unwanted revolved object is created, select Undo in the Edit menu, bring the cursor to the center of the revolved object with a click on a ruler, or a click at a point in the Top Figure window, and repeat the procedure again.

Modifying Revolved Objects

Control points can also be modified in revolved objects.

1. Enclose part of the object with the selection box in the Front view to select the object.

Select the shape again with another selection box while the object is selected, to activate the control point modification mode.

Now we can add points to round off the corners of the table.

2. Zoom in on the edge of the table.

3. Add two control points to the corners of the table edge.

Control points are added by dragging the mouse cursor across the line while holding down the Z + X keys (Win) / }{ + option keys (Mac).

4. Click the control point at the corner while pressing the Z + X key (Win) / 0 + 3 key (Mac) to delete the point.

The corner is now rounded. The quick rendering will also change accordingly.

5. Repeat steps 1. to 4. to round off the other corners.

Delete control points at the corners after adding points with the corner in between.

6. Modify the control points to freely edit the revolved object.

For instance, add control points on the leg of the table, and move points to change the shape of the leg.

Quick Rendering

In Shade, the perspective view in the Figure window can be quickly rendered. This technique is called Quick Rendering. Quick rendering provides a fast and easy way to view the completed modeling image.

1. Select Shading from Display Mode in the Rendering menu.

The perspective view is displayed as a quick rendering.

Modeling a Chair

Let us now move on to creating a chair using extruded objects. An Extruded object is a shape with a volume. First, we will create the seat portion of the chair.

1. Click the Z axis ruler in the Top view, to set the Z-axis cursor coordinate value.

Use the above figure as a reference for setting the cursor coordinate value. By clicking on the Z-axis ruler, the coordinate value along the Z axis is set. This will be the Z-axis location for our chair seat.

2. Select Part from the Part tool in the Toolbox, to begin creating a new part.

The rectangle that we will create in the next step will be contained in this new part.

3. While holding down the Ctrl key (Win) / option key (Mac), select Rectangle from the Create tool in the Toolbox.

4. Drag in the Front view to create a rectangle.

A rectangle is created. The rectangle (Closed Line) is contained in the part shown in the Browser window.

Note: Holding the Ctrl key (Win) / option key (Mac) will allow you to make multiple rectangles, without having to select the Create tool again.

Next, let’s create the back of the chair by drawing multiple rectangles.

5. Similarly, create a second rectangle in the Front view as shown in the figure below, then click the finish button in the Toolbox.

Pressing the finish button will end the repeated create function.

6. Select Skew from the Move tool in the Toolbox.

7. Click at A in the Front view and start dragging towards B to skew the back of the chair.

Now we can create an extruded object.

8. In the Browser window, select the Part that includes two Closed Lines.

A number of line objects contained in a part can be used together to create an extruded object.

9. Select Extrude from the solid tool in the Toolbox.

10. Drag the mouse cursor from A to B in the Top view.

An extruded object is created.

We will now make legs for the chair. Legs are created by extruding disks.

11. Using the figure below as a reference, click on the Y-axis ruler.

The height of the 3D cursor is set to create a disk directly under the seat portion of the chair.

12. Select Part from the Part tool in the Toolbox. The disks being created will be included in this new part.

13. Select Disk from the Create tool in the Toolbox.

14. Create a disk in the Top view as shown in the figure below.

A disk is created.

Now we will create three more disks by copying the first disk.

15. Select Translate from the Copy tool in the Toolbox, and drag the mouse cursor from A to B.

There are now two disks.

16. Select both disks in the Browser window. Both disks can be selected by clicking on one to select it, then clicking on the second one while holding down the Ctrl key (Win) / }{ key (Mac).

17. Use Translate in the Copy tool again to copy the two selected disks.