Animation

Introduction

The FRB Editor provides built-in support for animations. Simple games can implement animation with no code. More complex games can customize the default animations both in the FRB Editor and code.

This guide explores animations for top-down entities.

Default Implementation

If your game was created using the New Project Wizard then you should already have a Player entity that is fully animated.

We can see the animations used by the player by expanding the Player's Objects folder, selecting the SpriteInstance, and looking at its Animation Chains variable. Notice that this variable is set to the .achx file in its Files folder.

The SpriteInstance and .achx file in the Player entity are just like any other Sprite and .achx file - they an be modified as desired. This tutorial won't cover the details of modifying a .achx file. For more information on working with Animation Chains, see the Animation Editor page.

Selecting Animations

If we run the game, the Player is animated - it displays idle and walk animations in each of the four directions.

We can view the setup for animations by selecting the Player Entity, clicking on Entity Input Movement, and selecting the Animation item.

This section controls which animations are displayed on the Player's sprite.

Each row defines one set of animations, and the condition for when those animations play. Animations at the bottom of the list play if their condition evalutes to true. In other words, Idle animations always play unless the Walk conditions are satisfied.

The next section covers each variable.

Animation Name and Is Direction Facing Appended

Animation Name is the variable that determines which animation to play if the conditions in a given row are fulfilled. The Animation Name property uses a dropdown which lets you pick animations from the referenced .achx.

Notice that the names in this dropdown do not match the names in the referenced .achx.

If the Is Direction Facing Appended checkbox is checked, then FRB automatically assumes that animations will have Up, Down, Left, and Right versions, where the direction is appended. Therefore, FRB strips off these directions and only displays the animation name (removing duplicates).

This means that if you wanted to add additional animations to the .achx, or if you wanted to create a brand new .achx, every animation should have 4 versions, one for each direction. For example, you might add:

• AttackUp

• AttackDown

• AttackLeft

• AttackRight

Notes

Notes have no impact at runtime. You can add any notes that might help in development.

Min Velocity Absolute and Max Velocity Absolute

These values restrict when an animation can play depending on the player's current speed relative to the ground. If these values are null, then here are no velocity-based restrictions on when an animation can play.

Min Velocity Absolute can set the minimum speed for an animation to play. For example, by default the Player has a minimum velocity set for when the Walk animation plays.

Min Movement Input Absolute and Max Movement Input Absolute

These values specify min and max bounds for when to play the animation. These rely on the input for the character which has an absolute value of 0 - 1.

Animation Speed Assignment

The Animation Speed Assignment is used to optionally set the animation speed based on input or velocity.

• ForceTo1 forces the animation speed to 1

• NoAssignment removes all assignment of animation speed so it can be modified in custom code

• BasedOnVelocityMultiplier multiplies the specified value by the current velocity. Usually the specified value is less than 1.0f.

• BasedOnMaxSpeedRatioMultiplier multiplies the ratio of the entity's speed (current speed / max speed) by the specified value. Usually the specified value is 1.0f.

• BasedOnInputMultiplier sets the animation speed based on movement input values which which are between 0 and 1.

Movement Name

Movement Name is used to limit an animation to a particular movement. For example, you may set the movement value to Running if the user is holding down a run button. In that case you may want to limit the movement to if the Running movement values are set.

Custom Condition

The animation section of the top down Entity Input Movement tab is intended to contain all animations. Of course, games may need to assign animation using conditions that are not offered in this view. The Custom Condition text provides ultimate flexibility for assigning animations.

If this text box is not empty, then its contents are directly copied into generated code for an if-statement to decide whether the animation should play. The recommended approach is to create a single bool variable in your code which can be used to determine if an animation should play.

For example, consider an animation that plays when the player is taking damage. Your entity might have the following code:

bool IsPlayingDamageAnimation => 
    TimeManager.CurrentScreenTime - LastDamageTime < 1.0f;

IsPlayingDamageAnimation can now be used as shown in the following image:

Combining Conditions

Multiple conditions for whether an animation plays can be combined. For example, an animation might only play if the Movement Name is set to OnIce and if Min Movement Input Absolute is set to 0.3. This results in the animation only playing if both values are true.