Calculations

The most computational intensive calculation, is the determination of minimum distances from the shell. For distances to the side shell, this is done by sampling the distance from the bottom to top of the tank, but not above the depth of the vessel, and taking the minimum distance. For this to work, the hull must preferably be defined using a facetted representation.

For bottom damage, a similar method proved unreliable, so the distance is approximated by using the lowest point of the tank and assuming the bottom shell is at zero height.