noun
isosurface
Rare technical term used in mathematics, computer graphics, and scientific visualization for a surface of constant value.
同位面は、3次元スカラー場において値が等しい点を結んだ面である。
An isosurface is a surface connecting points of equal value in a three-dimensional scalar field.
Compound of 同 (same) + 位 (position/level) + 面 (surface), literally 'same-level surface'. The exact derivation is uncertain; it appears to be a technical coinage.