Here’s how to reference three.js in your Power BI Custom Visual project.
I have not tested to see if three.js actually works on powerbi.com, but this is how to resolve reference issues.
1. Setup your dev environment by following the instructions in this post: Power BI Custom Visual Dev Environment Setup Quickstart
2. Create visual and navigate to the new directory.
3. Install three.js
4. Install typings
5. Install three typings
6. Open in VS Code (or any editor)
7. Open tsconfig.json and add references to the three.js files
8. Add three.d.ts to /src folder and copy this code to that file
9. Open src/visual.ts and add this line to the top of the file
10. Instantiate a new THREE.Scene(); object in your constructor