How do you sync animation graph and animation blueprint with character movement and physics?

1 Animation Graph vs Animation Blueprint

An animation graph is a node-based system that defines the logic and flow of your character's animations. It can contain states, transitions, blends, layers, and other nodes that control how your character moves and reacts to different inputs and events. An animation graph is part of an animation blueprint, which is a subclass of the blueprint class that also contains variables, functions, and events related to your character's animation. You can create and edit animation graphs and animation blueprints in the Animation Editor.

2 Character Movement and Physics

Character movement and physics are two aspects of your character's behavior that affect how it interacts with the environment and other actors. Character movement is handled by the Character Movement Component, which is attached to your character blueprint and provides basic features such as walking, jumping, falling, and collision detection. Physics is handled by the Physics Asset, which is a collection of rigid bodies and constraints that define how your character's skeletal mesh deforms and reacts to forces and impulses. You can create and edit physics assets in the Physics Asset Tool.

3 Syncing Animation and Movement

To sync your animation graph and character movement, you need to use the appropriate nodes and variables that communicate between them. For example, you can use the Get Velocity node to get the speed and direction of your character's movement, and use it to drive a blend space node that blends between different walk and run animations. You can also use the Set Movement Mode node to change the character's movement mode, such as walking, flying, or swimming, and use it to trigger different state transitions in your animation graph. You can also use variables such as Is In Air, Is Crouching, or Is Falling to control the logic and flow of your animations based on your character's movement state.

4 Syncing Animation and Physics

To sync your animation graph and physics asset, you need to use the appropriate nodes and settings that enable and disable physics simulation on your character's bones. For example, you can use the Enable Simulate Physics node to turn on physics simulation for a specific bone or a group of bones, such as the head, arms, or legs. This will make your character's mesh react to external forces and collisions, such as being hit by a projectile, falling from a height, or ragdolling. You can also use the Disable Simulate Physics node to turn off physics simulation for a specific bone or a group of bones, such as the spine, hips, or feet. This will make your character's mesh follow the animation graph, such as standing up, walking, or jumping.

5 Setting Up Common Scenarios

To illustrate how to sync animation graphs and animation blueprints with character movement and physics, we will go through some common scenarios for your characters, such as walking, running, jumping, crouching, and rolling on the ground. Additionally, we will discuss how to make a character climb a ladder, hang from a ledge, or swing from a rope with physics simulation adjusting its pose and orientation based on the surface normal. Furthermore, we will explain how to make a character be hit by a weapon, fall from a height, or die from a fatal blow with physics simulation creating realistic ragdoll effects. For each scenario, we will provide the steps and nodes necessary for creating the animation graph, the animation blueprint, and the physics asset. Additionally, tips and best practices for optimizing your performance and avoiding common pitfalls will also be included.

6 Here’s what else to consider

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