( This ( ( defines ( ( a mapping ) ( between ( ( ( ( ( the ( user 's ) ) reality ) ( -LRB- ( ( distance ( from ( ( screen , ) ( size ( of window ) ) ) ) ) -RRB- ) ) ) and ) ( ( the ( virtual reality ) ) ( -LRB- ( ( ( ( position and ) scale ) ( of ViewPlatform ) ) -RRB- ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ defines) (NP (NP (DT a) (NN mapping)) (PP (IN between) (NP (NP (NP (NP (DT the) (NN user) (POS 's)) (NN reality)) (PRN (-LRB- -LRB-) (NP (NP (NN distance)) (PP (IN from) (NP (NP (NN screen)) (, ,) (NP (NP (NN size)) (PP (IN of) (NP (NN window))))))) (-RRB- -RRB-))) (CC and) (NP (NP (DT the) (JJ virtual) (NN reality)) (PRN (-LRB- -LRB-) (NP (NP (NN position) (CC and) (NN scale)) (PP (IN of) (NP (NNP ViewPlatform)))) (-RRB- -RRB-))))))) (. .)))
This defines a mapping between the user's reality (distance from screen, size of window) and the virtual reality (position and scale of ViewPlatform).
(ROOT (S (NP (NNP Distance)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN magnitude) (CC or) (NN size)) (PP (IN of) (NP (NP (NN displacement)) (PP (IN between) (NP (CD two) (NNS positions))))))))) (. .)))