After introducing the series and seeing how we can add simple vertex and edge geometry to a scene, today we’re going to start digging into the guts of the problem of how to display skeletons in the Forge viewer. This proved to be a really interesting process: I ended up learning a lot about how the Forge viewer and the three.js library it uses both work.
I don’t recall the full history of the Forge viewer’s use of three.js, but recent releases have all depended on r71. This can present challenges, largely because three.js is (at the time of writing) now at r96. Which means that many of the recent three.js samples focus on a different version of the library, so finding generic three.js code that works with the Forge viewer can be tricky. I’m not fully aware of the logic behind staying with r71, but I do know it would be a significant investment to move up to a more recent release. Beyond the effort required to upgrade the Forge viewer, the change would have a massive…