API Question Purpose of clbkAnimate()

[GLS]

Can someone explain to me what's the purpose of clbkAnimate()?
Reading the documentation it seems to be a performance gaining mechanism, so instead of calculating the animation position each time step and also calling SetAnimation(), we move the SetAnimation() calls to clbkAnimate() and so it is only called when needed (visual exists)... but I'm not fully convinced.
And then there's this from the clbkAnimate() documentation:

This callback is not used for the "semi-automatic" animation mechanism

Wa? :uhh:

 

[GLS]

In case someone also has the same question, I found out this is explained in section 1.10 of the API_Guide.pdf manual (although some functions have now a different name).