I have recently created some spaceship models with gmax. I want to make a trail of thrust that follows them for the walk animation. However, I am new to animating with this program and do not know how to. I realize that the best way to make the thrust itself would be to make a semi-transparent cone mesh behind the ship. The problem is I do not know how to make meshes that are only visible during appropriate animations. Can anybody give me some pointers please? I have tested the models and apart from their lack of animations they work fine.