[simulink] How to import a 3D model to the 6 DOF animation block?

I'm using simulink to design an UAV control.

Now I figured out the control law, got the UAV's trajectory and attitude (Euler angles) over time. I want to use the 6 DOF animation block to make an animation, and I have drawn a 3D model of my UAV with AC3d, in the format of .ac file. But I don't see how we import the model into the 6 DOF animation block. The product help doesn't seem to have mentioned it.

Can someone help me out? Thanks in advance.