Extrusion stretches 2D shapes into 3D objects.
By means of an AutoCAD program, two-dimensional (2D) designs can be turned into three-dimensional (3D)objects via several approaches, including a process called extrusion. This can be accomplished by positioning your cursor carefully and clicking and dragging on your 2D designs as desired.
1. Open AutoCAD and begin creating a 2D shape that you’ll extrude into 3D: Click the “Home” tab, then click the “Line” tool on the “Draw” panel.
2. Click anywhere in the main drawing window, then drag to define a line segment. Click and drag again to produce another segment, ensuring it’s angled differently from the first segment.
3. Click to finish the second segment, then right-click and select “Close,” which tells AutoCAD to add a third, final segment linking the end of the second segment with the start of the first. This action produces the triangle polygon.
4. Change your 2D viewpoint to a 3D one so that you can see the extrusion you’ll do in step 6. Select the “Conceptual” item from the “View” panel’s “Visual Styles” dropdown list. The conceptual visual style applies a simplified shading scheme to models in your scene so that you can see them clearly. Notice the 3D cube (called a “view cube”) that’s appeared in the upper right corner. This cube lets you orbit around your objects to view them from any angle.
5. Click and drag the view cube so that the following faces are visible: “Top,” “Front,” and “Side.” This view will allow you to clearly see extrusion in three dimensions.
6. Perform an edge extrusion: Click any point on one of the triangle’s edges to select the edge, then click the “Extrude” button on the modeling panel. Notice that the edge leaps up–extrudes–to follow your mouse pointer.
7. Drag the mouse to any screen location to size the edge’s height to your liking, then click to end the edge extrusion.
8. Press “Control-Z” to undo the edge extrusion, which is necessary to extrude the complete triangle.
9. Convert the triangle’s individual edges to a single, extrudable shape: Click any triangle edge, then click “Modify,” “Object,” and “Polyline.” Press “Enter” at the prompt to convert the edge into a polyline object, then select “Join” from the list that follows the prompt.
10. Click and drag a rectangular selection region around the complete triangle, then click to end the selection. Press “Enter” to complete the joining together of the edges.
11. Extrude the entire triangle by clicking the “Modeling” tab’s “Extrude” button, as you did in step 6. Click again to complete the extrusion.