Maybe this will help. I’ve programmed some explosions.
https://github.com/hofk/THREEg.js/blob/42dfd7a44ea6a327e0164466ad7c04f14b4c9a12/THREEg.js line 1220, 1421, 1495
see https://hofk.de/main/threejs/sandboxthreeg/MagicBoxTHREEg.html examples No. 11 No.12