Hmm, just to make sure:

Of course you don´t have to give the model exactly this action:

action model
{
my.material = shader_mat;
}

This was just a simple example. You can of course write many more lines of code into this action, which include your animation instructions ...

action model
{
my.material = shader_mat;
// many more instruction can be placed here ...
}

Cheers!