Arc Tool

The most interesting path is rarely a straight line. To help you get a little curvy, SketchUp for iPad offers 4 unique arc tools, each with its own method of creating an arc best suited to what you want to appear in your model:

  • Arc () - After activating the Arc tool you'll see a protractor to help you set the beginning, end, and desired angle of your arc. With this tool you'll set the center point of your arc, define a starting point, then define an endpoint.
  • 2 Point Arc () - The 2 Point Arc tool changes your cursor to a pencil. You'll set one end of the arc, then the other end, then define the bulge of the arc.
  • 3 Point Arc () - The 3 Point Arc tool also changes your cursor to a pencil. You'll set a starting point, a pivot point, and then an endpoint.
  • Pie () - Just like the Arc tool, you'll see a protractor after activating the Pie tool. You'll set the center point, starting point, and endpoint, but create a pie shape. This pie shape is also a face.

Each of these tools creates a curve entity made of straight-edge segments.

Optional Tool Modes

In SketchUp for iPad, each Arc tool has the following optional tool modes:

  • Increase Segments () / Decrease Segments () - You can use this tool mode either before or after drawing your arc. Each time you tap or click this tool mode you'll change the number of line segments in your arc. More segments means a smoother appearing curve with more inference points, while less means a more angled curve with less inference points.
  • Inference Locks - Activating one of these optional tool modes restricts drawing to a specific inference point:
    • Lock X () - The X axis or Red plane.
    • Lock Y () - The Y axis or Green plane.
    • Lock Z () - The Z axis or Blue plane.
    • Lock Parallel () - Parallel to a selection or the last line drawn.
    • Lock Perpendicular () - Perpendicular to a selection or the last line drawn.
Note: Inference Locks are one-time operations. Once you've drawn with an inference lock you'll revert back to the unmodified tool.

An additional optional tool mode is available for the 2 Point and 3 Point Arc tools:

  • Lock Tangency - When activated, once you complete an arc, this tool mode starts another arc tangent to the original. This mode can be used at the same time as any of the inference locks listed above.

iPad Input Methods for the Arc Tools

After choosing one of the Arc tools and activating any optional tool modes, you can use one of the iPad input methods in either Just Draw or Click Move Click mode to start drawing arcs.

Tip: The number you type in the Measurements box determines something different depending on which tool you've activated. :
  • Arc or Pie - Desired radius length.
  • 2 Point Arc - Desired chord length for your two points, then an angle for your bulge.
  • 3 Point Arc - Desired distance for your pivot point, then the desired angle for your endpoint.

Mouse or Touchpad

Arc or Pie - Click and release to set the center of the arc. Click again at the desired radius then move to your desired arc length.

2 Point Arc - Click and release at your starting point. Move to the end of your chord and click again. Move your cursor perpendicular to your chord and adjust the bulge distance.

3 Point Arc - Click and release at your starting point. Click again at your pivot point. Move away from the pivot to create your arc.

Multitouch or Apple Pencil

Arc or Pie - Long press to set the center of the arc. Drag and release at your desired radius. Long press again and drag to determine the angle and create your arc.

2 Point Arc - Long press to set your starting point, drag to the desired chord length, then release. Long press and drag again to create your bulge.

3 Point Arc - Long press to set your starting point, drag to where you want your pivot point, then release. Long press and drag again to create your arc.

For more information on how to incorporate arcs into your model see Drawing Arcs.

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