Imported Scale Animation Ignored in Viewport

Hi,

I just imported an fbx file with some animation. All looks fine in the little preview window in the lower right corner but when the animation plays in the main window, the object that is supposed to do a scaling animation doesn't change at all.

I really need this object to scale in order to cover part of the mesh. Maybe there's a better solution than that. What I want to achieve is a milling tool removing part of another object. I have a before and an after model, all I need is to reveal the after model. I do this with a DepthMaskShader, which hides a specific object when seen through the scaling object I mentioned before.

I hope you can understand what I mean ;)