https://github.com/WWBN/AVideo/issues/8713

node_modules/three/examples/jsm/nodes/utils/VelocityNode.js

@@ -0,0 +1,174 @@
+import { Vector3 } from '../../../../build/three.module.js';
+
+import { Vector3Node } from '../inputs/Vector3Node.js';
+
+function VelocityNode( target, params ) {
+
+	Vector3Node.call( this );
+
+	this.params = {};
+
+	this.velocity = new Vector3();
+
+	this.setTarget( target );
+	this.setParams( params );
+
+}
+
+VelocityNode.prototype = Object.create( Vector3Node.prototype );
+VelocityNode.prototype.constructor = VelocityNode;
+VelocityNode.prototype.nodeType = 'Velocity';
+
+VelocityNode.prototype.getReadonly = function ( /*builder*/ ) {
+
+	return false;
+
+};
+
+VelocityNode.prototype.setParams = function ( params ) {
+
+	switch ( this.params.type ) {
+
+		case 'elastic':
+
+			delete this.moment;
+
+			delete this.speed;
+			delete this.springVelocity;
+
+			delete this.lastVelocity;
+
+			break;
+
+	}
+
+	this.params = params || {};
+
+	switch ( this.params.type ) {
+
+		case 'elastic':
+
+			this.moment = new Vector3();
+
+			this.speed = new Vector3();
+			this.springVelocity = new Vector3();
+
+			this.lastVelocity = new Vector3();
+
+			break;
+
+	}
+
+};
+
+VelocityNode.prototype.setTarget = function ( target ) {
+
+	if ( this.target ) {
+
+		delete this.position;
+		delete this.oldPosition;
+
+	}
+
+	this.target = target;
+
+	if ( target ) {
+
+		this.position = target.getWorldPosition( this.position || new Vector3() );
+		this.oldPosition = this.position.clone();
+
+	}
+
+};
+
+VelocityNode.prototype.updateFrameVelocity = function ( /*frame*/ ) {
+
+	if ( this.target ) {
+
+		this.position = this.target.getWorldPosition( this.position || new Vector3() );
+		this.velocity.subVectors( this.position, this.oldPosition );
+		this.oldPosition.copy( this.position );
+
+	}
+
+};
+
+VelocityNode.prototype.updateFrame = function ( frame ) {
+
+	this.updateFrameVelocity( frame );
+
+	switch ( this.params.type ) {
+
+		case 'elastic':
+
+			// convert to real scale: 0 at 1 values
+			var deltaFps = frame.delta * ( this.params.fps || 60 );
+
+			var spring = Math.pow( this.params.spring, deltaFps ),
+				damping = Math.pow( this.params.damping, deltaFps );
+
+			// fix relative frame-rate
+			this.velocity.multiplyScalar( Math.exp( - this.params.damping * deltaFps ) );
+
+			// elastic
+			this.velocity.add( this.springVelocity );
+			this.velocity.add( this.speed.multiplyScalar( damping ).multiplyScalar( 1 - spring ) );
+
+			// speed
+			this.speed.subVectors( this.velocity, this.lastVelocity );
+
+			// spring velocity
+			this.springVelocity.add( this.speed );
+			this.springVelocity.multiplyScalar( spring );
+
+			// moment
+			this.moment.add( this.springVelocity );
+
+			// damping
+			this.moment.multiplyScalar( damping );
+
+			this.lastVelocity.copy( this.velocity );
+			this.value.copy( this.moment );
+
+			break;
+
+		default:
+
+			this.value.copy( this.velocity );
+
+	}
+
+};
+
+VelocityNode.prototype.copy = function ( source ) {
+
+	Vector3Node.prototype.copy.call( this, source );
+
+	if ( source.target ) this.setTarget( source.target );
+
+	this.setParams( source.params );
+
+	return this;
+
+};
+
+VelocityNode.prototype.toJSON = function ( meta ) {
+
+	var data = this.getJSONNode( meta );
+
+	if ( ! data ) {
+
+		data = this.createJSONNode( meta );
+
+		if ( this.target ) data.target = this.target.uuid;
+
+		// clone params
+		data.params = JSON.parse( JSON.stringify( this.params ) );
+
+	}
+
+	return data;
+
+};
+
+export { VelocityNode };