Optotrak and vizard

[Canucks]

We are doing a project and I'm hoping you can give me some feedback . In our project, the research participant wears the optotrak on his leg and walks on the treadmill. There is a 3D screen in front of him which is an empty room full of obstacles such as step , boxes ... we are trying to measure how high the person lift is leg for each obstacle
Should I use an avatar and the avatar reads the location from optotrak ( so when person moves , avatar moves too) ? If yes , does avatar has a function for lifting leg and doing steps?
If not how do you do this ?