Applying bone weights causes mesh geometry to unpredictably "explode"

[Evgeni_Popov]

Maybe this thread and related links can help:

Trouble creating programmatic skeleton and bones

Hello, I am trying to create a simple skeleton that consists of individual meshes that are attached to each bone, no weights. I’ve created a basic skeleton with pelvis, thigh and shin bones, but I’m not getting the result that I expect. The skeletal viewer shows a strange visualization of bones, where they are all just pointing straight up. And, only the LINES visualization seems to display anything, the SPHERES and SPHERE_AND_SPURS style displays nothing. I was expecting the lines between…

But as @sebavan explained, creating rigged meshes by code is not an easy task…