After you export an FBX file from Revit® 2011 products the materials, textures and lights are not visible if opened in a 2010 product.
Revit 2011 products use mental ray® Protein 2.0 appearances. Revit 2010 products use mental ray Protein 1.0 appearances. Materials, textures and lights will not be visible unless opened in a compatible 2011 product.
For example if the FBX file created from Revit 2011 is opened in Autodesk 3ds Max® 2010 the materials, textures and lights will not be visible. The FBX file would need to be opened in Autodesk 3ds Max 2011 to view the materials, textures and lights.
Products: Revit Architecture;Revit MEP;Revit Structure