Forge viewer extension that creates Streamline objects

StreamlineExtension.ts

/// <reference path='../../types/three.d.ts' />
import { Logger } from '../../core/Logger';
let logger = Logger.getInstance();
import { ShowableExtension } from '../../core/ShowableExtension';
import { DasherModel } from '../../core/DasherModel';
import { Streamline } from './Streamline';

export class StreamlineExtension extends ShowableExtension {

  private _overlayScene = "DasherStreamlinesOverlay";
  private _bounds: THREE.Box3;
  private _lastLineCreated: Date;

  constructor(viewer: Autodesk.Viewing.Private.GuiViewer3D, options: any) {
    super(viewer, options);
    this._lastLineCreated = new Date();
  }

  public load(): boolean {
    this.createUI(
      'toolbar-sensor-streamline',
      'Streamlines',
      'DasherControlSensors',
      'flash'
    );
    this._dataModel.on(
      DasherModel.eventTypes.CurrentHistoricTimeChanged,
      this.onCurrentHistoricTimeChanged
    );

    this._bounds = this.viewer.utilities.getBoundingBox();

    logger.log('StreamlineExtension loaded');

    return true;
  }

  public unload(): boolean {
    this.destroyUI('DasherControlSensors');
    this._dataModel.off(
      DasherModel.eventTypes.CurrentHistoricTimeChanged,
      this.onCurrentHistoricTimeChanged
    );

    logger.log('StreamlineExtension unloaded');

    return true;
  }

  public show(): boolean {
    this.viewer.impl.createOverlayScene(this._overlayScene);
    return true;
  }

  public hide(): boolean {
    this.viewer.impl.removeOverlayScene(this._overlayScene);    
    return true;
  }

  private addToScene(obj: THREE.Object3D) {
    this.viewer.impl.addOverlay(this._overlayScene, obj);
    this.viewer.impl.invalidate(false, false, true);
  }

  private removeFromScene(obj: THREE.Object3D) {
    this.viewer.impl.removeOverlay(this._overlayScene, obj);
    this.viewer.impl.invalidate(false, false, true);
  }

  private onCurrentHistoricTimeChanged = (time: Date): void => {
    let now: any = new Date();
    let elapsed = now - <any>this._lastLineCreated;
    if (elapsed > 100) {
      this._lastLineCreated = now;
      this.createStreamline(10, 3, 0.8, 20, 100, this._bounds);
    }
  }

  private createStreamline(
    vertCount: number,
    width: number,
    opacity: number,
    grow: number,
    displayTime: number,
    bounds: THREE.Box3
  ): void {
    let dims = this.viewer.getDimensions();
    let verts: THREE.Vector3[] = [];
    // Create random points...
    // X: at fixed intervals across bounds
    // Y: 40% of bounds plus 20% variability
    // Z: 45% of bounds plus 10% variability
    for (let i = 0; i < vertCount; i++) {
      verts.push(
        new THREE.Vector3(
          bounds.min.x + (i * (1 / (vertCount - 1))) * (bounds.max.x - bounds.min.x),
          bounds.min.y + (0.4 + (0.2 * Math.random())) * (bounds.max.y - bounds.min.y),
          bounds.min.z + (0.45 + (0.1 * Math.random())) * (bounds.max.z - bounds.min.z)
        )
      );
    }
    this.addToScene(
      new Streamline(
        verts,
        new THREE.Color(Math.random() < 0.1 ? 0xff00ff : 0xffff00),
        width,
        opacity,
        grow,
        displayTime,
        new THREE.Vector2(dims.width, dims.height),
        (s: Streamline) => { this.removeFromScene(s); }
      )
    );
  }
}

ShowableExtension is a class that allows extensions to integrate into the Forge viewer UI (adding icons to the left-hand toolbar in Project Dasher). It doesn't do anything very complicated, but it doesn't make sense to share as-is.

DasherModel is much more complicated, and is at the core of Dasher. If I posted this you'd be even more confused.

I originally posted this extension file to give you a sense of how to use the Streamline class: you shouldn't lose time trying to get it working, the best approach is to use the Streamline creation code in a separate application.

Thank you very much for answering me. I am still in school and I am more interested in this. But I just got in touch and will encounter many problems. I hope I can leave you a message here in the future, okay?

I suggest posting to StackOverflow: the Forge team monitors it and has much more experience with supporting development with the viewer. Feel free to post specific questions related to blog posts via keanw.com, though (but via the blog, rather than GitHub). Again, I really don't have time to provide more general support.

Okay, thank you very much for your suggestions, and once again thank you for your answers. I wish you a happy life!