threejs-interaction

Raycasting in Three.js detects clicked 3D objects by converting pointer coordinates to normalized device coordinates, casting a ray from the camera, and evaluating intersections against your scene's targeted object lists.

You add OrbitControls by integrating Three.js control add-ons into your scene, enabling pointer-driven camera navigation schemes that let users rotate, pan, and zoom within interactive 3D web experiences.

Converting world coordinates to screen coordinates in Three.js translates 3D positional data into 2D viewport space, allowing you to accurately position HTML overlays or map user input to 3D positions.

Yes, Three.js supports PointerLockControls to implement first person interaction, allowing you to integrate mouse-driven looking and keyboard state updates for interaction-driven gameplay and navigation.

Handling mouse input for hover selection in a 3D scene requires setting up a Raycaster with normalized mouse coordinates, firing rays on pointer move events, and routing interaction feedback to the intersected object.

Optimizing Three.js raycasting performance involves filtering intersectable objects using layers or targeted object lists, reducing the number of meshes evaluated during pointer move events and click detection.