As the title says, Safari literally chokes itself, whenever I try to update BoundingBox of model like 3DBenchy (the framerate is at 4FPS at best). I tried on different Macs (El Capitan, Sierra, High Sierra, with and without external Video Card), and there was the same problem. Funnily enough, whenever i switch to a different browser (like Firefox or Google Chrome) it works with rock solid 60FPS on the same machine.
I was able to isolate the test case, and you can see it here: https://damoch.github.io/three-test/
If you open the console, there is "API", that you can mess around with:
* rotate = false //disables rotation of object
* updateBox = false // disables update of bounding box on every frame
* helper.update() // updates bounding box
* loadStl(path) // loads STL file from path (I'm not sure if it works). if called without parameter, it loads default file, which is 3DBenchy.stl.
I've opened issue on three.js issue tracker already -> https://github.com/mrdoob/three.js/issues/14201
Created attachment 341901 [details]
I was able to reproduce this on WkWebView control in Cocoa, so it's not limited to Safari.