Various small samples demonstrating basic ECS code patterns.

This sample is similar to the jobs tutorial: Seekers (green cubes) and Targets (red cubes) each move slowly in a random direction on a 2D plane. A white debug line is drawn from each Seeker to the nearest Target.

In the subscene, the "Simulation" GameObject has a "SettingsAuthoring" component with a "Spatial Partitioning" value which controls how the Seekers find their Targets:

• None: The brute force option. For every Seeker, the NoPartitioning loops through every Target to find the Target closest to the Seeker.
• Simple: This option uses the same spatial partioning demonstrated in step 4 of the jobs tutorial.
• KD Tree: This option uses a k-d tree (a tree of points in a k-dimensional space) for spatial partitioning.

Spatial partitioning allows each Seeker to find its closest target without having to consider every Target. Even the simple partitioning solution scales much better than if we use no partitioning at all, and the k-d tree solution performs even better at very large scales. For example, with 30,000 Seekers and 30,000 Targets on my 8-core CPU, the TargetingSystem is about twice as fast using the k-d tree solution compared to the simple solution, and more than a hundred times faster compared to the no partitioning solution.

At runtime:

• The SpawnSystem creates two sets of boxes: 10 white boxes and 10 black boxes.
• The MoveSystem moves the white and black boxes back and forth starting in opposite directions.
• The CollisionSystem changes the color of a box when it intersects another: white boxes become pink and black boxes become green.

The CollisionSystem performs the intersection tests in one of two ways, toggled by a #if in the code:

• The #if true solution copies the entity id's and transforms of the boxes to arrays, then it loops over every box (using SystemAPI.Query) to compare its position against every other box.
• The #if false solution does the work in a job and avoids having to copy the boxes by passing the box entity chunks to the job.

A very simple first-person controller that demonstrates basic input handling and coordination with a GameObject (the camera).

This sample demonstrates how to update systems at a fixed rate, similar to the MonoBehaviour.FixedUpdate method.

At runtime:

• The RandomSpawn system spawns 200 boxes at regular intervals and positions them at random points along the edge of a circle.
• The MovementSystem moves the boxes downward and destroys them when their y coordinate becomes less than zero.

Because the boxes are positioned in a parallel job, randomly positioning the boxes requires a unique random seed value for every box.

Change the material of rendered entities at runtime.

This sample defines material override components, which allow you to control shader parameters by setting the override component values.

This sample uses baking to define a spline. At runtime, boxes move along the spline paths.

These samples demonstrate different ways of expressing state changes. Numerous cubes are spawned on a plane, and clicking toggles all cubes within a radius between two states: white and stationary; or red and spinning. There are four solutions:

• Enableable component: The cube state is represented by enabling and disabling a component.
• Structural change: The cube state is represented by adding and removing a component.
• Value change: The cube state is represented by a component value.
• Profiling: This variant exists just for comparing performance of the other three variants. (For easier profiling, the cube state is set every frame rather than only when the user clicks.)

This sample uses Burst-compiled jobs to efficiently generate a texture.