Using the Geometry Cache Track

Describes how you can add and use the Geometry Cache Track to scrub through and utilize Geometry Cache assets within Sequencer.

Windows
MacOS
Linux
On this page

The new (and experimental) Geometry Cache Track enables you to scrub through a Geometry Cache and render it out with frame accuracy. Once you have imported your Alembic file into Unreal Engine 4 (UE4) and added it to a Level, you can add it to a Level Sequence and add the Geometry Cache Track to play your content.

Steps

For this How-to guide, we are using the Blueprint Third Person template project. You will also need an Alembic file to import into the Engine. If you do not have your own asset, download this Sample File.

  1. Import your Alembic file(s) into UE4 as a Geometry Cache and define your desired settings.

    UsingGeometryCache_ImportWindow.png

  2. Place your Geometry Cache in the Level, then create a Level Sequence and add it to Sequencer with the + Track button. 

    GeoCache_02.png

  3. Click the + Track button for the newly created Track and select Geometry Cache from the Tracks menu. 

    GeoCache_03.png

  4. Scrub the Timeline to view a playback.

    GeometryCache_Example.png

    You can also set the Level Sequence to Auto Play before selecting Play in the Level.

End Result

With the Geometry Cache Track **set, you can scrub through your content or it will play back automatically when your Level Sequence plays. 

You can access the properties of the Geometry Cache by right-clicking on the Track in the Tracks Window. From the properties menu, you can change which Geometry Cache asset is being used, add a Start or End Offset, or adjust the Play Rate. There are also options for the Section itself and whether to play the animation in Reverse**. 

GeoCache_04.png

The following properties are available for Geometry Cache tracks from the right-click context menu, under Properties

Property

Description

Geometry Cache

Specifies the Geometry Cache asset to play.

Start Offset

Number of frames to offset into the beginning of the animation clip.

End Offset

Number of frames to offset into the end of the animation clip.

Play Rate

Defines the playback rate of the animation clip (lower to slow down, increase to speed up).

Select Skin
Light
Dark

Welcome to the new Unreal Engine 4 Documentation site!

We're working on lots of new features including a feedback system so you can tell us how we are doing. It's not quite ready for use in the wild yet, so head over to the Documentation Feedback forum to tell us about this page or call out any issues you are encountering in the meantime.

We'll be sure to let you know when the new system is up and running.

Post Feedback