If desired, on the Options Bar, clear the Perspective option to create a walkthrough as an orthographic 3D view. Also select a view scale for the 3D view.
If you are in a plan view, you can vary the height of the camera by offsetting it from a selected level. Enter a height in the Offset text box and select a level from the From menu. This can give you the effect that the camera is going up a flight of stairs.
Place the cursor in a view, and click to place a key frame.
Move the cursor in the desired direction to draw the path.
Click again to place another key frame. You can place key frames anywhere, but you cannot change their position during creation of the path. You can edit the key frames after you finish the path.
To finish the walkthrough path, you can do any of the following:
Click Finish Walkthrough.
Double-click to end the path.
After you finish placing camera key frames, Revit LT creates a walkthrough view under the Walkthroughs branch of the Project Browser and assigns it the name Walkthrough 1.