Designing the perfect roads

Roads lie at the core of Per Aspera. A well designed colony is connected seamlessly by a vast network of expanding roads. In our game, it’s very important to plan your building placement carefully! The ultimate directive of AMI is to terraform the planet... but one of the first steps to accomplishing that is by creating efficient resource transportation. That’s precisely where roads come in.



The foundation of a good colony is an optimized network of roads and buildings connected with Workers. When you begin a new structure, a new road will be created that links it to your pre-existing structures. Each particular road is calculated on the fly based on the real topology of Mars. The roads will try to minimize the travel time between buildings, as the Workers travel faster the flatter the road is. We modelled the different speeds on a 1985 paper commissioned by the US Department of Transportation called “Methods for Predicting Truck Speed Loss on Grades” (by Robert Gillespie), adjusted for Mars gravity.



For the curious cats, these animated tendrils are not a visual effect, it’s the actual pathfinding algorithm running in real-time! We implemented an algorithm from a paper by Galin, Peytavie, Maréchal and Guérin called “Procedural Generation of Roads”, which consists of a hyperdense A* search on a dynamic lattice. This is a very novel technique designed to be used in real civil engineering road planification. We think Per Aspera must be one of the first games to use such a technique!



We were also inspired by classic games like The Settlers (AKA Serf City: Life is Feudal), which provided hours and hours of optimization fun! We hope our players will have just as much fun planning and optimizing their settlements.



https://store.steampowered.com/app/803050/Per_Aspera/