How to Create 3D Solid in AutoCAD: Step-by-Step Guide

To create a 3D solid in AutoCAD, use commands like BOX, EXTRUDE, or REVOLVE. Start by drawing a 2D shape, then apply these commands to convert it into a 3D solid model.

Syntax

Here are common commands to create 3D solids in AutoCAD:

• BOX: Creates a rectangular 3D solid by specifying length, width, and height.
• EXTRUDE: Converts a 2D closed shape into a 3D solid by extending it along a path.
• REVOLVE: Creates a 3D solid by revolving a 2D profile around an axis.

Each command requires you to specify points or dimensions to define the solid.

autocad command line

BOX
Specify corner of box or [Center]: 0,0,0
Specify length: 10
Specify width: 5
Specify height: 3

EXTRUDE
Select objects to extrude: (select 2D shape)
Specify height of extrusion: 7

REVOLVE
Select objects to revolve: (select 2D profile)
Specify axis start point: 0,0,0
Specify axis end point: 0,0,10
Specify revolution angle: 360

Output

Creates a 3D solid box, extruded solid, or revolved solid based on input dimensions and selections.

Example

This example shows how to create a 3D solid box and extrude a 2D circle into a cylinder.

autocad command line

1. Type <code>BOX</code> in the command line.<br>2. Specify the corner point at <code>0,0,0</code>.<br>3. Enter length: <code>10</code>, width: <code>5</code>, height: <code>3</code>.<br><br>4. Draw a circle with center at <code>15,0,0</code> and radius <code>3</code>.<br>5. Type <code>EXTRUDE</code>, select the circle.<br>6. Enter extrusion height: <code>7</code>.

Output

A rectangular 3D box appears at origin and a cylinder appears at (15,0,0) with height 7.

Common Pitfalls

• Trying to extrude an open 2D shape will fail; ensure the shape is closed.
• Not specifying the correct axis for REVOLVE can create unexpected shapes.
• For BOX, entering zero or negative dimensions will cause errors.
• Forgetting to switch to a 3D workspace or view can make it hard to see the solid.

autocad command line

Wrong: EXTRUDE an open polyline (no solid created)
Right: Close the polyline first using <code>PEDIT</code> then extrude.

Quick Reference

Command	Purpose	Input Required
BOX	Create rectangular 3D solid	Corner point, length, width, height
EXTRUDE	Make 3D solid from 2D closed shape	Select shape, extrusion height
REVOLVE	Create solid by revolving 2D profile	Select profile, axis start/end, angle
PEDIT	Edit polylines to close shapes	Select polyline, close option

Key Takeaways

Use BOX, EXTRUDE, or REVOLVE commands to create 3D solids in AutoCAD.

Always ensure 2D shapes are closed before extruding.

Specify correct dimensions and axis points for accurate solids.

Switch to a 3D view to better visualize your solid models.

Use PEDIT to close open polylines before extrusion.