要素内補間
または成分で表せば、
( x p y p z p ) = ( x p 0 y p 0 z p 0 ) + ( x e u x e v y e u y e v z e u z e v ) ( u p v p ) {\displaystyle \left({\begin{array}{c}x_{p}\\y_{p}\\z_{p}\\\end{array}}\right)=\left({\begin{array}{c}x_{p0}\\y_{p0}\\z_{p0}\end{array}}\right)+\left({\begin{array}{ccc}x_{eu}&x_{ev}\\y_{eu}&y_{ev}\\z_{eu}&z_{ev}\end{array}}\right)\left({\begin{array}{c}u_{p}\\v_{p}\end{array}}\right)}