Modelling - base rules

[ndar]

Model orientation : while it is of course possible to orient a model in any desired direction in space, some naval architecture conventions are applied when carrying out calculations.
For example :

- orientation  : X longitudinal (+ fwd or aft makes no difference), is required for hydrostatic coefficients and righting arms in heel to be computed correctly
- sections : sections need not be present for hydrostatics to be computed as Orca3D integrates the surface mesh, but they are required for coefficients to be computed
- performance : hull resistance algorithms assume that the surface model at hand extends congruently.  So, for example, for planing resistance calculations make sure that only the bottom portion of the model is being used

[Admin]

I would agree with all of this, except that +X must be aft, especially for resistance calculations.