Surfaces > Swept Surfaces

Animate Sweep Options

Sweep: Snapshots – Create new curves from the “snapshots” of the animated curve. You can use these curves as construction curves for tools such as Skin, Extrude, and Rail Surface.

Connect Snapshots – Create a new skinned surface from the snapshots of the animated curve.

Snapshots: This option is has no effect when Sweep is set to Connect Snapshots.

Individual – Do not group the resulting “snapshot” curves.

Grouped – Group the resulting “snapshot” curves, as if you had picked them and chosen Group from the Edit menu.

Parameters: Tip
Set global and local animation parameters using Param Control in the Animation menu.

All – Animate all parameters of the animated curve.

Global – Animate only the global parameters of the animated curve.

Local – Animate only the local parameters of the animated curve.

Hierarchy: None – This option controls whether extra objects are animated in addition to the curve.

Only animate the picked curve.

Below – When Sweep mode is Snapshots, animate the picked curve and any geometry below it in the DAG.

When Sweep mode is Connect Snapshots, animate the picked curve and associated CVs.

Above – Animate the picked curve and any geometry above it in the DAG.

Both – Animate the picked curve, associated CVs, and any geometry above and/or below it in the DAG.

Frame Range: All – Animate the picked curve over the entire range of available frames of animation.

Use the By Frame slider to set the interval between snapshots.

Prompt – Prompt for the start frame, end frame, and frame interval every time you use the tool.

Option Window – Set the start frame, end frame, and frame interval once in the option window, for every subsequent use of the Anim Sweep tool.

Start/End Frame: These options appears when Frame Range is Option Window.

The start and end frames of the curve’s animation to create snapshots from.

By Frame: This option appears when Frame Range is All or Option Window.

The number of frames in each step between snapshots.

For example, a value of 1 takes every frame, 2 takes every other frame, 3 takes every third frame, and so on.

Sweeping an animated curve

Create a surface by sweeping out the movements of an animated curve through time, as if the animated curve was leaving a “trail” of construction curves as it moved.

If you are proficient using the animation tools, you can use Anim Sweep to easily accomplish complex or unusual effects that are difficult or impossible using Extrude or Swept. Instead of using options to change the sweep, you have total control over the cross-section of the new surface at every point.

The Anim Sweep tool can sweep curves animated by:

Set keyframe.
Set motion.
Set key shape.

You can animate the whole curve, and/or the CVs of the curve.

To sweep an animated curve

Animate the curve. (See the Animating book for more information on using the animation tools.)
Pick the animated curve.
Click the Anim sweep icon, or choose Surfaces > Swept Surfaces > Anim Sweep from the tool palette.
If the Frame Range option is set to Prompt, type the start frame, end frame, and frame increment, separated by spaces, on the prompt line.
The frame increment is the number of frames to step through between each snapshot. For example, an increment of 1 takes every frame, 2 takes every other frame, 3 takes every third frame, and so on.
The Anim Sweep tool takes a snapshot of the curve at each step of the animation, creating a series of construction curves.
- If the Sweep option is set to Snapshots, the Anim Sweep tool asks you whether you want to keep the curves. If the snapshot curves look wrong and you want to change the animation and try again, click No.
- If the Sweep option is set to Connect Snapshots, the Anim Sweep tool automatically skins a new surface along the snapshots of the animated curve.

Tips and notes

When the Sweep option is set to Connect Snapshots and you pick the curve in the SBD window, you must pick the node directly above the curve.
To use CV animation, set the Hierarchy option to Below or Both.

Limitations

In Surfaces > Swept Surfaces > Anim Sweep, the ABOVE option does not work.
If an object is animated hierarchically, a non-root node is selected, and Anim sweep is invoked with hierarchy set to ABOVE, animations above the picked node are ignored. Similarly, if the option is BOTH and there is animation above, it will not be recognized.

Copy the geometry, delete the other branches, and anim sweep from around the root node with hierarchy set to BELOW.