add findTriangle() in Surface class
add getDistanceAlongPolyline() to Polyline. The code is extracted from MeshNodesAlongPolyline.
add Mesh object as a member variable of MeshNodesAlongPolyline and MeshNodesAlongSurface. Use getDistanceAlongPolyline() in Polyline.
add LinearFunction in MathLib
add SpatialFunction in NumLib/Function
add a linear function of space
add linear interpolation along polyline and surface
add tests for spatial functions
use getLength() to calculate a segment length
pass a Point object to findTriangle(). add documment
changed a constructor to take std::array. allow N_VARS=0. use std::inner_product
remove a default value for default_value
rename to LinearInterpolationOnSurface. remove a default value. documents interpolation.
add comments
fix compiling errors in test
fix a bug that zero distance was not accepted
added export of 3D meshes to TetGen smesh
added support for creating TetGen smesh files for meshes with static layer thickness
added tetgen export option for 3D meshes to gui
renamed and documented new methods