View-based greenery: A three-dimensional assessment of city buildings' green visibility using Floor Green View Index

•A new indicator named Floor Green View Index (FGVI) is proposed for quantifying visual amenity of urban vegetation.•FGVI is defined as the area of visible urban vegetation observed from a certain floor in a building.•New methods are proposed for calculating the indicators.•FGVI of over 100 buildings in the Lujiazui region, Shanghai, are calculated and analysed.•FGVI can be used to facilitate the assessment and planning of urban construction projects.