On Visual Variables of 3D Map Symbol

On the basis of visual variables in traditional 2D map representation,this study extends the symbol variables into the domain of dynamic change and inter-operation,and establishes the variable system of 3D map symbol.This study considers three kinds of variable parameters: status,operation and dynamic change.The status variables refer to traditional visual variables such as shape,size,spatial layout and so on.The operation variables are special to the 3D map symbol including four aspects: rotation,scale,LOD hierarchy and shade tuning.The dynamic change variables are made up of duration,change rate,change order and rhythm.Through the cognitive experiment,the paper investigates the application of 3D symbol visual variables to represent the quality,quantity,relation and dynamic characteristics of spatial phenomena.