TheEffects ofSceneComplexity, Stereovision, andMotionParallax on Size Constancy inaVirtual Environment

Inthispaper, theeffects ofthreevisual factors: scene complexity, stereovision and motionparallax on correct perception ofa virtual object's sizewereanalyzed inan immersive virtual environment. We designed a controlled experiments settoincorporate visual conditions that reflected all twelve different configuration combinations ofthethree visual factors. Undereachvisual condition, subject performed thetask of making judgments ofthesizes ofavirtual object displayed atfive different distances fromhim/her. A total numberofeighteen subjects participated inourstudy. Thesubjects' judgments andthe corresponding actual sizes ofthevirtual object wererecorded. Basedonthecolleted data, twoquantitative measures ofsubjects' performance werederived andanalyzed. Theresults ofour experiments wereconsistent across themajority ofthesubject population andsuggested that scenecomplexity andstereovision could havesignificant impact ontheperformance ofauserof virtual environments tomakecorrect judgments ona virtual object's size. Onthecontrary, motion parallax, either produced by thevirtual environment orbytheobserver, mightnotbea significant factor indetermining that performance.