actually i exported a .mdx file from a custom campaign "Zuka", i tried to animate it in mdlvis, and its obvious that it has a vertex weights, because whenever i tried to rotate one of its arms, one of its vertices seems to just move slightly while others really move..
i dont know if its really because of vertex weight but thats what i saw in that model.
another thing i did is i imported that .mdx file to ms3d and put a joint to the same location of that bone(i did this because when you import a model to ms3d, the bones were not imported), and assign same vertices.. then animate it, there is a big difference with the animation..
so i suspect it its really because of vertex weight, but i dont know how that modeler of that model did that magic..
another, i noticed that when rotating that .mdx model in mdlvis, a controller type appears in the middle of the pane, (the linear, bezier, hermite... ones), but when i converted .ms3d model with bones to mdx then animate it with mdlvis, that controller type wont appear..