All source zones must be FE-Tetra FE-Brick or be IJK-ordered when doing linear interpolation in 3D

This is because linear interpolation requires a consistent and structured grid to ensure accuracy and consistency in the results. FE-Tetra and FE-Brick are types of finite element meshes that provide structured and regular grids, while IJK-ordered grids are typically used in structured grid models such as grid-based numerical models for fluid dynamics. Using other types of grids or unstructured meshes may lead to inaccurate or inconsistent results in linear interpolation.