Embers of Empire Update – AI Dynamic Navmesh / A Star Experiments


Ever since this summer I’ve been struggle to make my AI better. I have Behavior Trees in and really easy to debug logic now, but the path finding has become an issue. The AI stumbled across the age old robotics problem of escaping a concave obstacle. I added a big derelict alien space craft that is integral to the story and a super cool set piece to fight around and explore, but the AI acts like an idiot ramming itself into the structure with the current avoidance AI. The current avoidance works ok for smaller obstacles but when things go on for miles in one direction, path finding seems to be necessary. So, off to AI school I go again.

I looked into the new dynamic navmesh for Unity and its ability to be created on surfaces that don’t necessarily have to be horizontal. I thought I came up with a good hack, but it still doesn’t always work, and the dynamic building of individual navmeshes for lots of ships is going to be a problem when battles scale up. In the video below the agent doesn’t change its angle much, even tho I programmed it to do it and it was doing it a week ago… A great demonstration of how hacky and unreliable it is. It was an exciting idea tho, especially given all the off the shelf stuff you can use with the navmesh like steering and formations. Too bad..

Since I don’t really like how the navmesh system fails a lot and building the navmesh over and over is necessary and slow because you need to keep orienting the plane in different directions so the ship can move in 3D, I decided to start looking into other stuff. 3D A* was an obvious place to go, but A* is not super fast-especially in 3D over great distances. So, I am looking at a Jump Point A* where you can have a mesh of nodes, but you don’t have to traverse symetrical nodes and you can jump to ones where you need to make a decision. I am thinking of it as like a line of site type thing. If you don’t have a direct shot to the target, traverse through nav nodes that connect to create a clear path.

Currently I am working on ways of generating efficient node maps of my levels. I am thinking of using non-uniform cubes represented by a bounds object at runtime. When baking the navmesh info, the cube might start very big like 1km in volume and if it detects a collider within it, it will break into small cubes that test for colliders until you have some areas with finer navmesh data. This way the empty areas of the map would have fewer navnodes to traverse, but when a ship gets in close to an object they need to path find around the nav data will be more refined. This of course sounds great on paper, but I need to make sure I can generate such a thing without locking up Unity or making the player wait an hour for the next scene to load. If it works I think I can add some very cinematic dog fights and ship battles with the small craft dodging and weaving in and out of complex space stations or between capital ships.

New Let’s Play Video – Space Warfare: Infinite Plays Angels Fall First

I’ve decided to do a series of Youtube Let’s Plays of games that I enjoy playing that I also draw inspiration from. I plan to show off some of the game’s features and discuss the things I am working on in Space Warfare: Infinite. So, first up is a game I’ve been playing a lot of – Angels Fall First. This game has been in development for awhile, and I’ve always been inspired by their Space, Air, and Ground combat. They cover both space sim combat and first person shooter combat. You feel like you are in a big war every time you play. I love the feel of the game when you touch down in a warzone and I think the ship models and locations are pretty cool. I definitely look to some of their fighter models for inspiration. I also love being able to run around inside the big ships.

Angels Fall First came out on Steam Early Access Oct 1. You can grab it here: http://store.steampowered.com/app/367270/

They also have a website at http://www.affuniverse.com/

Developer Log #1- Modeling The Fleet in Space Warfare: Infinite

Over the last few weeks I’ve been trying to limit my programming time to focus on 3D modeling. I find switching between Unity and Blender to be difficult, so just working on making stuff in Blender has helped my productivity in creating new art assets for the game.

Sketching and modeling in Blender.

Sketching and modeling in Blender.

I have a list of space ships that need to be made and I’ve been working through it. I am almost ‘done’ one faction’s main ships. I still need to model a new fighter–and I might do a 3D cockpit while I am at it. Keep in mind nothing is really done. Everything is WIP. I’ve haven’t quite gotten my skills yet for painting textures and generating bump maps so there is still more work to be done. Also, as time goes on, these early models might need to be redone if I get better.

A new battlecruiser - 1 kilometer of destruction.

A new battlecruiser – 1 kilometer of destruction.

Above is the battlecruiser. Its basically the battleship class of the space fleet. For some reason I can’t use battleship. The ISC ships are going to be more boxy like current military ships and tanks. The other faction will have more sloped / angular plates on their ships.


Huge carrier ship capable of launching fighters and corvettes from those two bays in the front.

This is the carrier ship. It will have some point defense turrets on it, but other than that it will rely on its fleet and fighter squadrons to defend it. The carrier is also big enough to launch corvettes which will be used as anti-fighter type ships.


The corvette. A ‘small’ ship.

The corvette is the latest model I’ve made. Its meant to take on small missions and has weapons geared more towards fighter management or hit and runs on capital ships. The ship is fast but would probably get eaten up if it tried to go head to head with ships of the line.

The Destroyer-class. This ship is 500m long. Its got around 8 turrets mean for engaging other cap ships and point defense. It has a deck mounted rail gun and an  internal beam weapon.

The Destroyer-class. This ship is 500m long. Its got around 8 turrets mean for engaging other cap ships and point defense. It has a deck mounted rail gun and an internal beam weapon.

The Destroyer will be the workhorse of the fleet. The cruiser is a force to be reckoned with but these destroyers will pack a punch. A couple destroyers can take out a cruiser pretty fast.

Very early space station.

Very early space station.

After these, I plan to remake the fighter and then start on the enemy faction. I also have dreadnoughts on my list as well. They’d probably be 2km. Additionally, I started messing with Space Stations.

Here is a video where I talk about the ships and compare their sizes…

Space Warfare: Infinite on the Space Game Junkie Podcast!


At the beginning of the week I was lucky enough to be on the Space Game Junkie Podcast! The hosts of the podcast have a website devoted to all types of new and old space video games. (Space Warfare: Infinite even has its own wiki page on their site!) If you are looking for a new game to play, they have 99 episodes covering all sorts of games as well as video reviews of games. Its a big source of information and inspiration for me, so it was great to be on the show and chat with hosts about making space games.

Here is the link to the Space Game Junkie Podcast featuring Space Warfare: Infinite…  (for the younger audience of this blog – some of the hosts on the podcast let a few curse words slip so perhaps make sure that it’s ok with your parents to listen if you are still living with your parents… )


All in all, the podcast was a lot of fun! I still think my voice sounds weird and I need to work on my elevator pitch about the game, but it was totally cool to see some people who really love space games play the game I am making. I also got some good feedback for things to fix like FPS controls confuse people when the shift key changes the controls…. the A/D key might be a slide instead of roll or at least I should add a slide/strafe feature since folks are expecting it after Elite, the targeting needs to be fixed because its confusing and not super responsive (I’ve already fixed the targeting subcomponents issues)–I need to add arrow indicators or make the offscreen target box larger and brighter so folks can track the closest target. I’ve got a few movies and games to check out as well.

Space Warfare: Infinite – Dev Log – Capital Ship Battles, Ship Switching, New Cameras, Unity 5

Sometimes it feels like not much has happened in the last week or two, but actually if I reflect back, Space Warfare: Infinite has made some pretty good progress.


Ship Switching

One of the key features of the ultimate vision of the game is in. It needs to be refined and tested, but the core functionality is there. (Meaning you can do it, but sometimes the game breaks…) You can now switch between ships in your fleet! You can be flying along fighting in your tiny fighter and then press a key and swap to a big capital ship destroyer. Fire off a few beam blasts and jump into another ship. The ship you left will keep flying and fighting as the AI takes over.

The ultimate idea is that you can choose to effect the outcome of the battle in all different capacities and see the battle from all different perspectives. Eventually you will be able to give some basic tactics at the beginning of the battle to each ship in your fleet and then during the fight you can issue commands – currently just in the Comm menu– but probably eventually in a little more RTS-ish like a holographic command screen on a command ship.


Capital Ship Control!

Another thing that wasn’t possible a week ago was capital ships doing anything other than sitting in one place and firing from their turrets. While that was cool, its not very practical for a giant flying behemoth covered in guns to sit in one place while fighter ships dance circles around its turrets. So now the AI is hooked up — cap ship specific AI maneuvers are still a work in progress — so the capital ships will fly around and slowly chasing things and try to hit them with the ‘big dumb guns’ on their bow while their turrets focus on whatever catches their attention.


Capital ships helped add a new feature to ships and AI – the idea of types and classes. Now AI can look for enemies in their own class size and choose to only attack those. What this means is that if a I set a big capital ship like a Destroyer to only attack other ‘Large’ class ships, it will not try to chase fighters and instead will try to aim its big guns at other big less nimble targets. The turrets currently run on their own AI so they do whatever they’ve been set to do. Fighter turrets look for fighters, anti-cap turrets aim at big ships, point defense targets incoming missiles. Eventually AI and the player will be able to command turrets to attack selected targets or get all turrets to focus fire. This will truly be the way to take down the bigger ships faster. The big ships have an absurd amount of armour and hull strength, but don’t actually last long when hit with powerful guns. Fighter cannons take more rounds than most fighters have and thats with every round hitting only one side of the armor.

Cameras and Controls

So not only do Capital Ships fly on their own, but now the player can control one too. At the moment this means you can fly it around, roll it so the turrets have a good angle to pick up targets, point it in a direction and fire a giant plasma cannon or a beam weapon from the front. Eventually more controls will come — like commanding all the turrets, launching fighters from carriers, commanding other ships from a bridge, launching nukes, managing shields and power.

Additionally, the capital ship controls made the need for new cameras to be added. Trying to fly a kilometer long skyscraper through a combat situation from a first-person or even a third-person perspective is somewhat difficult. A middle mouse button orbital camera was added so that you could get views from various angles around the ship as well as zoom out to see what is around. I’ve also added an FPS mouse look that puts you in the middle of your ship / or your cockpit on the fighter and allows you to look around and behind you. I am mapping these to the F1-12 keys like in Privateer and Wing Commander games. I have a bunch of directions plus the orbit and mouse look setup in there. The functionality is there, but I am still working to make it better.


Unity 5

I also upgraded to Unity 5 because I keep looking at the graphics advances, the new physics engine, and the frame rate boosts and just needed to make the jump. I thought the move would fix a turret issue I had where my turrets were spinning my ships – but I think the way I finally fixed it probably worked in Unity 4.6 as well. My problem involved wanted to have turrets (and other future stuff) be able to take their own damage and be targeted and destroyed. The turrets move but are children of another big damageable rigidbody thing as well. But I needed a collider and a rigidbody on the turrets so that hits would register on them. Every time I did this the turret or turrets would spin the ship, fly off the ship into space, stay on the ship but turn on their sides. Anyway, rumor has it you didn’t need a rigidbody on a collider in Unity 5, but that doesn’t seem to be true. I understand that now moving a static collider doesn’t result in a penalty, but I guess it wasn’t the same as my problem. Anyway, I figured out that if I turned my colliders into triggers on the turrets, they’d stop messing with my ships, stay in place and take damage. I don’t know if this is best practice but it works! I need to make sure other triggers are not included on the collision layer mask for projectiles, but other than that it works!

So while Unity 5 didn’t really solve my issue, it did speed up the game. I seem to be able to get more stuff going on the screen than before while still getting a decent FPS.


One downside was most of my scripts lost their inspector set variables and the UI doesn’t know where any of its components are. I’ve been slowly fixing it all, but things are a little scrappier at the moment. A few above screenshots have white boxes where UI is supposed to be, that was the most noticeable Unity 5 upgrade effect! It slowed work on other stuff down for sure. I am hoping tho that now that I am up and running with Unity 5, I can make use of the new shader and its better use of threading to keep the game fast and furious.

Space Warfare: Infinite – Dev Log – AI Dogfighting Maneuvers and Launch Tube

Part of last week and into the weekend has seen a lot of time devoted to reworking the AI. I also wanted to add some new visual elements and while I did not get around to modelling a bunch of capital ships, I did model a launch tube for the player to fly out of.

Launch Tube


The launch tube is really just a mock up. It will get modeled in Blender someday in a more fleshed out way, but I wanted to add a more cinematic feel to the game play. It works! I have a whole idea for the first mission of the game and it will involve a FPS style run through the ship to the launch bay and then getting shot out into space. I won’t spoil too much, but lets just say my influences are books like The Lost Fleet, Old Man’s War, Armor and Starship Troopers. They all give a similar feel of a first battle against a superior force. I think it will be a rewarding intro if I can pull it off.


I’ve been reworking the AI from a Switch/Case (I know, terrible) to a class based approach like the one on the Unify Wiki and the one described in Unity 4.x AI Programming — but with my own twist.

Screen Shot 2015-02-08 at 9.19.02 AM

I am starting with what they explain, but I am working on making it more modular so that I don’t have to write an base AIScript for every pilot style. I want to be able to drop behaviors and maneuvers onto a ship and have it fly a certain way. I am getting there. I’ve built a maneuver component that has the ship fly a pattern, the pattern is imported into the AI State at runtime. It’s still not exactly where I want, but it’s starting to work pretty well.

Once I perfect the way the pilots pull in the patterns, I will also be building in better decision making for the AI. I’ll build in which patterns are best for different situations offensive and defensive. Additionally I will be adding in cooperative moves and player commands to get assistance from wingmen. I’ve also got plans to start making AI adhere to the same targeting situations at the players so the player can lose an enemy etc.


After the dogfighting is passable, I will start working on getting the capital ships moving. They need to move differently than the fighters and small craft, but currently they just sit there and hope their turrets have something to aim at. It will be real cool when those things start to move.

Space Warfare: Infinite – Dev Log – Modeling ships, Base classes and Explosion Debris

I’ve been busy since the last Dev Log, but sometime its hard to tell what to update folks on. Cleaning up code is super useful for the game, but doesn’t make for screenshots. As the base ship class gets more and more cleaned up and unifies the player and AI scripts, some cool things will happen. More ship variety, AI that can use and switch between different weapon systems on their ship to match their situation, the ability to target a Friendly, press a button and hop into that ships cockpit while AI takes over yours… (yeah thats a big one…). Almost there….

I’ve been fooling around with Blender, but need to take a few online courses on UV Mapping because I am failing or at least asking ‘this has got to be easier’. I guess art assets could be a good reason for a kickstarter in the future if I can’t get the game to look right.


A semi-ok blender model of a fighter. not the best….

I did have great success in modeling debris from exploding ships. Basically just rectangular twisted scraps of metal. Thats about my skill level. But it looks cool!!


changed the zoom out for the player explosion so you can see it and take it in for a few seconds.

Space Warfare: Infinite – Dev Log: New UI Stuff and Mission Scripting

It’s hard to remember exactly what I’ve added from update to update and I hope to make more regular blog posts to keep track. Over the last week I’ve been doing more under the hood work as well as some random visual stuff to go along.


Point Defense Turrets

One major addition is point defense turrets (unique 3D model pending – for everything in the game really) that targets missiles and does a pretty ok job destroying them. The idea is that big slow moving nuke missiles fired off during capital ship battles will get knocked out of the sky — unless some ace fighter pilots can get in there and save take out those turrets! (We’ve got to justify fighter craft existence in some way right?) The code for my turret targeting had to be modified so that they could be choose to target something other than ships. This will probably come in handy one day when we want stuff to shoot bases or asteroids or cargo.

On a side note – My test model of a cap ship is a basic wall of turrets and no energy limits or management has been implemented yet, but I am sure in the future ships will not be impossible walls of laser cannons. I have some thoughts on how that would work in the future. I figure I will make ships in a component type way where you need segments to hold various things like power cores, munition bays, barracks etc. The segments will be physical chunks of the capital ship increasing the size and mass. Bigger can be heavy on fire power, but they are going to have blind spots and attack vectors that small fighters can exploit.


The turrets shooting the purple lasers are Point Defense turret. That explosion was once a slow moving nuke.


As you can see from the above picture, I am also working on adding some elements that will allow me to start messing around with story elements and missions.  Without comms, it’s tough to present any story or mission. The communications box will just pop in and then disappear so it’s not always interfering with view. Additionally, I am working on a Freespace 2 style ‘command’ scheme both to communicate with your fleet members and to answer back to other folks who contact you over the comm. At the moment my # keys are used for weapon equips and other usable systems, but I am going to have a comm key that enables a ‘comm’ mode for using numbered menus.

Missions! Scenarios! 

Once comms were in, I needed something to control sending comms messages. I’ll be using XML files to build missions or scenarios that will load and play out when you enter a sector or trigger something. I am thinking of them as missions and scenarios, because the story arcs will be framed more as missions, but if you are free roam and not following the main story, the game might load up various scenarios unfolding in the system you jump to so there is always something to do. So far its not too complex – we can spawn new ships and tell the player stuff.

http---makeagif.com--media-1-12-2015-prnLZoSpeaking of spawn new ships – I thought just randomly dropping ships in wasn’t cool so I gave them a warp in effect. Most fighters would probably warp in while inside a carrier, but this will do for now. I am looking forward to having a whole fleet warp in in front of a player.


UI has also been worked on. The left side info box has been cleaned up a little and now works with the weapon select feature. Shows you what weapons are equipped and how much ammo they have left. Additionally the center reticul now has the energy bar, the hull hp bar and an armor bar. I also tried dropping a model of your targeted ship in the enemy info box, but I couldn’t get it to feel just right and then my game crashed. I may end up taking screenshots of the different ship models and just make sprites for them in the UI. Behind the scenes I also have a working sector map that updates positions in real time. I plan to convert it one day to something usable like another way to give orders – certainly it will be one of the ways to do that as a Captain on a cap ship.



Hull, Armor, Shields 

Armor was another thing I’ve added. It’s minor at the moment, but eventually it will play a big role in balance. There will be different classes of armor plate and corresponding classes of ordinance. A Class 1 projectile will lose about 25% of its expected damage against a Class 2 armor. Class 3 would reduce it to 50% and a Class 5 would basically just shrug it off with no damage. Super armored battleships might not even worry about attacks from fighters or lower class weapons. A bomber or heavy fighter with a higher armor class would have a real advantage in a dogfight against ill outfitted pirates. As for shields, I am not planning on having them on smaller ships. If you’ve been following my game dev tales, you know that I like explosions. Shield technology severely hinders the explosions:minutes ratio. Fighters and their brethren must blow up a lot. Also, I get bored when a dog fight against one enemy takes forever. Why build a high-tech spacefaring fighter jet that can’t take down its prey quickly? All fights should be quick and dangerous so shields are out for the small fries. Fly a capital ship and you can manage shields to your hearts content.


Dev Log for Space Warfare: Infinite – Beam Weapons are awesome

Still working on capital ship weaponry and it’s fun! I’m actually doing a lot of clean up under the hood since my general programming process is get something working that I can play with on the screen as fast as possible and worry about making the code better later. I am in a make the code better phase because capital ships are far more involved than fighters and they are forcing me to break out some of the systems I just hard coded into my fighter scripts so that after I am done, I’ll be able to iterate more ships, turrets, weapons, other objects faster.


Capital ship with one beam weapon lays waste to a fighter wing…


One example of this current decoupling is beam weapons – a totally different style of ‘projectile’ that still works with the components I built. The main turret I made last weekend just fires off regular cannon projectiles which are the same things that the fighters shoot. It’s been my standard projectile along with missiles for a long time. Standard cannon projectiles do 1 damage to the hull (armor and shields haven’t been implemented yet…) and missiles do a bunch more. The beam weapons are set to 1000. They cut through anything and can destroy multiple ships in one hit. I’ll probably dial it back but its fun to watch the thing just vaporize fighters like gnats. I envision this level strength weapon to be a capital ship attack weapon so the turret will probably track slower and generally just target other big ships. I might also make a short range faster tracking anti-fighter beam to punish players who get to close. The beam weapon definitely makes a cap ship something to fear.

On the technical side – I used a line renderer with a collider for the beam and I hacked together a lense flare and light at the origin of the beam. I might add another lense flare type thing to places it hits stuff so that it looks like a weld torch. Might be a cool effect that is different from the regular sparks and stuff of other weapon collisions.