Motivation

We want to have assets that take the lowest amount of memory, but that animate at the highest possible quality.

Uncompressed, an animation contains a key for every frame in the animation and for each joint that has been exported. We usually want to reduce the amount of joints and keys to minimize the size. We have separate channels for rotation keys and position keys per joint.

To compress animation character uses the Resource Compiler (RC).

Compression of Existing Animations

To adjust compression settings of the animation load your character by double-clicking on it in Explorer.

Choose your animation in the Animations tree in Explorer. Note that both .i_caf and .animsettings should present and writable.

Note for P4 users: .i_caf and .animsettings files should be synced and checked out locally. If they are not, use a perforce client to do so first.

Now you can see the compression settings in the property panel on the right:

Setting Compression Settings

Removing channels (position/rotation keys) automatically

Reducing the amount of keys within a channel

The goal should be at this point to have an animation that takes as little as possible but looks good. Sometimes though, playing around with global values for a whole animation is not enough, and we will need to fix up individual joints that show choppy motion.

 

Per-Joint Setup

Per joint control over the epsilons removal process

Per joint control over the compression value

Define Animation Tags

Each animation can have a list of tags associated with it. Tags can be used to:

You can find Tags in the Properties window when you select animation in the Asset Explorer.

To add a new tag use the context button with tag count and select "Add" in popup menu. Then click on an empty string to enter its name.

To remove a tag you can use use context menu (RMB on the tag name).

 

For curious readers: tags are case insensitive. I.e. the tag "CINEMATIC" will be treated the same way as "cinematic".

Batch-compression

Compression Presets can be used to apply the same set of compression rules to multiple animations at once. You can locate them in the Compression section of the Asset Explorer.

Each compression preset entry defines a filter that can match animations according to a certain filter, i.e. a set of criteria such as folder, filename or tags. Such criteria can be combined using logical operations into a complex condition, like "in folder and doesn't contain specific tag but has substring in name". When multiple presets match the same animation only the first one is used. You can always preview which compression setting entry was applied to animation in the animation properties (by selection a specific animation in the asset explorer).

Compression presets are saved in: <GameFolder>/Animations/CompressionPresets.json.

DBA Creation

DBA files are bundles of animations which can be streamed in and out as one. They are typically smaller and take up less memory than individual animations. For detailed information, see Database File (dba).

 

DBAs are created using the same filters as compression presets. I.e. you can define a combination of criteria, e.g. location, name or tags to select animations for a specific DBA.

DBA descriptions are saved into: Animations/DBATable.json and used by the RC at build time to create actual DBA files.

The DBA Table can be found in the Compression section of the Asset Explorer.

Define Animation Filter (DBA or Compression Presets)

An Animation Filter allows you to choose a set of animation files for specific DBA or Compression Preset. An Animation Filter is defined as a tree of condition nodes.

Some of them are condition nodes that can be used to group other nodes, like "And" and "Or", the rest are used to check some of the criteria of the animation.

Condition

Description

And

Succeeds when all of the child conditions succeed.

Contains In Name

Checks for a substring within animation name.

Has Tags

Checks if animation has all of the listed tags.
Tags are stored in ANIMSETTINGS and can be set in Animation Properties (see above).

In Folder

Check if animation is located within a specific folder.

Or

Succeeds when at least one of the child conditions succeeds.

Skeleton Alias

Checks if animation uses specific Skeleton Alias. Skeleton aliases are defined in the Skeleton Table.