Partial base model for unit normal on road. Extend this model appropriately to define final user model.
partial function normalBase
extends Modelica.Icons.Function;
input Real s = 0 "Roads surface parameter 1 (usually arc length along road)";
input Real w = 0 "Roads surface parameter 2 (usually lateral direction)";
output Real e_n_0[3] = {0, 0, 1} "Unit normal of road at (s,w), resolved in world frame";
end normalBase;