Skip to content

Latest commit

 

History

History
36 lines (22 loc) · 2.21 KB

README.md

File metadata and controls

36 lines (22 loc) · 2.21 KB

BlendTree1D Sample

This sample demonstrates a simple 1D blend tree System that implements a speed blending with Walk, Jog, and Sprints.

What does it show?

This sample demonstrates how to convert a Unity Blend tree asset to a DOTS blend tree asset using the conversion pipeline. Since the three clips don't loop the pose correctly, while converting the blend tree the sample also bakes the three clips to fix the looping.

Converting from GameObject to Entity prefab

It uses a Spawner MonoBehaviour which needs a Rig Prefab (the animated character) and a Graph Prefab (the animation source that drives the rig).

The Spawner converts the Rig Prefab which has a RigComponent to a Rig Entity prefab with an Unity.Animation.RigDefinition.

The Spawner also converts the Graph Prefab to convert all embedded Unity assets (UnityEngine.BlendTree and UnityEngine.AnimationClip) into DOTS animation asset (Unity.Animation.BlendTree1D and Unity.Animation.Clip).

ComponentSystems

The RigSpawnerSystem is a ComponentSystem that handles the instantiation of the Rig Entity Prefab.

The BlendTree1DGraphSystem is a ComponentSystem that handles 3 operations:

  • Creation of the DFG (DataFlowGraph) with:
    • A TimeCounterNode that accumulates time in its memory;
    • A TimeLoopNode that loops the time of the clip (this node has three outputs: one for the number of cycles, one for a normalized time, and one for the looped time which value is in the range [0, clip duration]);
    • A BlendTree1DNode that does the blending between the North-East and North-West directions;
    • A FloatRcpSimNode that computes the inverse of a float. The value of the output of the TimeCounterNode is connected as an input to this node, so that it outputs the speed.
  • Update of the graph parameter's by sending message to the Blend Tree node;
  • Destruction of the DFG.

Time Management

Each rig entity has a component DeltaTime. This component is updated by the UpdateAnimationDeltaTime system. Using a ComponentNode, the graph connects the value of the DeltaTime component to the converter node ConvertDeltaTimeToFloatNode, and this node's output is used as an input for the nodes that require a delta time.