Loadstar Devlog - Alpha 5 - Traffic ⛗

This one is a biggie, I didn't realise how much I had done until I came to write this devlog. During the past couple of months I've focused on adding NPC traffic to the galaxy and improving the combat AI. Sounds quite well bounded but it had a way of reframing all my past work and pushing me to rethink a few things to make sure all the game systems are joined up and working together.

You are not alone

Up until now yours would be the only ship on the solar system map. Fights would be randomly triggered as you travelled through space similar to travel the world map in Final Fantasy. I wanted to change that to make you feel like you are just one ship in a galaxy filled with commerce and crime.

Loadstar now generates NPC traffic, each ship has a purpose, a route it is travelling and a destination to reach or a home base to return to. These ships are either freighters or pirates, though I intend to add more types in future updates.

NPC traffic going about its business

Pirates will enter a system and look for juicy targets and attack, that could be you or it could be another NPC. They will steal cargo and return to their base once their hold is full or they've taken enough damage for one voyage. Freighters will buy low and sell high, picking up cargo in a system where it is cheap and travelling to a system where they can make a profit.

Hunting

Because the game knows where each NPC is going, it's possible for the player to follow a ship even when it enters hyperspace to go to another solar system. Whenever a ship enters hyperspace (or arrives from hyperspace) it will create a temporary wormhole which can be seen on the solar system map. You can inspect it to see what ship created it, where they are going and when they will arrive. If you have a fast ship you can pursue them and be waiting for them when they arrive!

This is going to be important when I come to doing missions and bounty hunting in future updates as you will be able to follow the trail of an NPC through multiple systems in order to track them down.

Ship en-route to the Ran system

Trade Routes

I realised that in order to make realistic freighter traffic I first needed to identify trade routes within the galaxy. Loadstar's economy is based on the combination of the economy types present within each system along with the population levels of the planets. This determines how much supply of each commodity (or lack of it) there will be and that controls the price.

Since I wanted to detect these trade routes to make believable NPC freighter traffic, I decided I could also make this information visible to the player to help them learn the ropes and understand the economy. Loadstar now displays trade routes on the galaxy map.

Trade routes around the Sol system

Security and Corruption

I wanted different solar systems to have a different feel, some are wealthy, built up, well protected and policed, some are lawless or corrupt. The player must be able to choose whether they want to do a safe milkrun or run the gauntlet through a tough system. And their choice should matter, high risk high reward. I needed a way to decide how many pirates there should be in a system, how many freighters. Should the ships be large and well equiped or small junkers barely space worthy.

Each system has allegiance, wealth, government and population

Each system already has a faction allegiance, government type and wealth and popluation levels. I now use this to decide the levels of security and corruption present in each system. High security will mean fewer pirates and larger ships. When a pirate does appear in a secure system they are going to come prepared for a fight. High security also means lower profits because there are plenty of freighters hauling goods and keeping prices down. Low security systems will tend to have smaller, less well equiped ships and more pirates.

Sensors and Momentum

Once I added NPC traffic I had a problem, the map suddenly became quite cluttered and it was tough to manage the information. I added clustering so that when zoomed out ship and station icons are grouped together which helped but something still didn't feel right.

I felt like I was an air traffic controller rather than a captain of a ship. I had perfect knowledge of everything that was happening, there were no surprises.

I tried adding a sensor range, a circle around your ship. You can only see ships inside your sensor range. Immediately it felt right. I could make an educated guess about where the traffic would be, travelling from the star to a planet with a space station for example, but I couldn't know what was there until I explored. I could see a suspicious ship on an intercept course but I still had time to react.

Except I didn't because of momentum.

You win again, gravity!

The realistic(ish) Newtonian physics I had implemented meant my ship handled like an ice cube on a griddle. Once again realism clashed with gameplay and gameplay won. I chose to fudge the acceleration a little so that it's possible to change direction much faster while still keeping enough momentum to make it feel right. I'm really happy with the result.

In future updates I will probably add new ships parts which improve sensor range or allow you to scan another ship's cargo. The kind of specialist equipment every pirate should have.

Sensor range circle

Plot an Intercept Course

You control your ship in Loadstar by clicking where you want to go and letting an autopilot work out the details for you rather than controlling the ship directly. This actually made the NPC traffic a little easier to do because there is already an autopilot which works out how to get a ship to a destination. I just had to work out what the destination should be in the first place.

However, this didn't account for hitting a moving target. You can now intercept another ship by clicking on it. The autopilot will calculate an intercept course, trying to go to where they are going to be instead of where they are. It took a lot of maths and calculus but I got there!

Intercept course

Combat AI

Up until now all fights happened when a pirate attacked you, there was no NPC traffic so there was no way for you to attack anyone. But now that changed, you could be fighting someone who doesn't want to fight. I had to revisit the combat AI. The AI will figure out if it thinks it can win or not at the start of combat and continuously reasses this as the battle plays out. They might choose to fight, but they also might choose to flee. Depending on their goal, they will prioritise different systems and allocate their crew accordingly. They can now hyperspace to escape combat or even surrender if things look bleak.

Making a getaway

All this means I needed a way to tell you the combat is over, summarise what happened and give you the chance to plunder the defeated ship if possible. Introducing the plunder dialog:

Plunder dialog

Next Up

I have been working to give everything a bit of a glow up and add some juice, like shield flares, camera shake, better looking lasers and such because I'm planning to update the trailer and the Steam page. It hasn't been updated since I launched it last year and it doesn't even have crew management in it.

I think after the trailer is up the next version will be around law and order - adding police, pirate bases, legal status, prison sentences, smuggling, all that good stuff.

Thanks for reading, see you in the future.

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