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A ball in the world.

A brick in the world.

A cylinder in the world. Its symmetry axis is local Z.

A RigidGroup is a bunch of objects that move together. All Ball, Brick, and Cylinder child descendants are glued together and will move as one rigid body.

If you want to add animations, you must set followSkeletonId, use a JointAnimator to animate it, and add JointAttachment objects to glue objects to the joints. There are some AI tools to automate this.

Use this as a Folder. There is no special behavior, it is simply for organization.

A mesh in the world.

To animate this mesh visually, you must set followSkeletonId and use a JointAnimator to animate it.

Use skeletons to animate all your objects. Skeletons are just a collection of Joint objects, which are just locations + rotations in space that you can glue objects to in order to animate.

Joints must go inside a Skeleton or another Joint.

The bindPose is the initial reference location that movements in an animation (JointAnimation) are relative to.

Use JointAttachments to glue objects in a RigidGroup to a Joint. The objects will move physically with the joint, not just visually.

Use this object to play an animation.

This makes a Skeleton move, based on a JointAnimation and a Clock. Multiple of these can point to the same skeleton; they blend their animations until weight reaches 100.

Start and stop an animation by saying _________

This is how you define an animation. This object contains a JointKeyframe child for each frame in the animation. Those keyframe objects have a JointPose child that says how to offset each Joint relative to its bindPose.

You play this animation using a JointAnimator.

A child of JointAnimation.

A child of JointKeyframe.

A clock is just an internal helper object that tells us how far along we are in an JointAnimator or Sound. Clock lives on the client. It can use either client time or estimated server time as its reference.

An image or "texture" that is shown on an object. Albedo is the main texture. The other fields are optional PBR properties.

You can never create a Player object yourself. It is automatically created and deleted when a player joins and leaves. It is important for you to set the head and controls, or the player won't be able to see or move.

Every Script is either a Server or Client script.

• Client scripts run on every client and can only do a limited set of things like show UI and play animations.
• Server scripts run on the server so can do elevated things like access storage and leaderboards.

Imports:

• Simply write import { functionName } from './scriptName' to use scripts as modules.
• You can use setTimeout() and setInterval(). Scripts expose all web APIs except fetch.
• Scripts and their path names are set once, when the script is created.

Server-Client:

• You should communicate between the server and client by calling functions across the network.
• Write 'use server' at the top of a Server script to make all exports accessible to Client scripts.
• Write 'use client' at the top of a Client script to make all exports accessible to Server scripts.
  • Exports should be async functions.
  • The first argument to client functions must be the player's user id.
• You should validate server function inputs and client function return values.

UI:

• We expose React-like syntax to draw UI on the screen.
• You may only use <div>, text, arrays, null, className, onClick, and onHover primitive props on divs.
• You can use common Tailwind class names. Do not use style props or unsupported HTML tags.
• useState() works like usual.
• createState() works for state that comes from outside react, eg for 'use client' functions. This is similar to useSyncExternalStore.
  • Write createState(initialValue). The .get() function automatically subscribes the relevant React components to re-render when .set() is called.

Managing Objects:

• Only the server can create objects.
• With few exceptions, only the server can modify objects (exceptions: player locations, animation clocks, etc).
• All objects in the world are replicated to all users. You cannot create an object on just one client.

Controls the whole world's sun, ambient lighting, sky color, and skybox. The sunOrientation points from the world toward the sun and uses degrees.