Base camp

Base Camp screen

click to enlarge

 

One of the things Free Company had been missing from the classic X-Com design locker (that I have been so gleefully looting) is some kind of base building mechanic in the campaign layer. Well no longer, despite the lengthy pauses in keeping this blog up to date I have been steadily trundling away on new stuff for the game here and there in between some minor computer troubles and a new gym regime (designed to keep me alive long enough to finish this game).

Screenshots of menus are never that gripping but this particular one happens to capture almost everything I’ve been doing recently. First up was a code refactor of the campaign UI to support multiple potential screens worth of menus ( rather than having everything stupidly dumped in one rapidly filling up place). This was to support a couple of new screen ideas, the first of which is the base building one you see above in it’s first incarnation. To sell the base screen I decided to make a whole bunch of fancy images in a consistent style to represent the ideas I had for buildings. I think it came off reasonably and it is a lot more satisfying to gain that little icon of a tavern than it would be just building a bunch of text descriptions.  Though I also spent a bit of time revamping the text description displays by making the tool-tips used throughout the campaign (and in some areas of the tactical battles) more aesthetically pleasing. They now have slightly rounded corners, a carefully adjusted amount of alpha and the use of new text rendering options. The engine can now, with a little bit of text markup, render a bold version of a font (as long as you remembered to load one) and assign text colours with a much more dynamic system of css like id tags loaded from an xml so it is easy to add new colours and easy to adjust the colour of all the text that uses the same tag.

And finally you can actually use that menu now to start construction of the available buildings and as long as you have the cash and wait a few turns your company will be the proud owner of a new tavern/stockade or whatever. Of course at the moment all of the buildings are somewhat ceremonial as the other systems they are going to unlock , contribute to or  buff have either yet to be built or are yet to be decided upon. I have a few ideas of what they are going to do but nothing is set in stone yet.

I’m quite enjoying working on the campaign layer at the moment as I feel that every time it improves it’s helping to add the purpose and context that I feel has been a bit lacking in the tactical battles. However, there is still a chunk of necessary work that needs to go into the current tactical battles around mercenary special skills, path finding and play speed improvements and better enemy AI. At some point soon I want to muster the drive to finish off those areas to an ‘alpha-ready’ standard so I can start to think about some kind of release that will garner much needed player feedback.

In not-Free Company-news there is a new remake of X-Com due next month by Civilization developing titans Firaxis.  I have of course preordered it out of my ‘research’ budget mainly so that I can swipe all of its good ideas and twist them to my own dark ends.

 

As always any comments or encouragements are welcome in the handy box below, or you can follow me on twitter and bark commands to me via that instead.

 

 


Olympian feats

…are pretty distracting!

 

Work has been progressing slowly on Free Company the last couple of weeks, school has broken up for the summer so my teacher girlfriend and I have been enjoying the freedom from the school schedule by larking about. Now the Olympics has proven to be an additional distraction as I try to type code on my laptop while being constantly glued to the tv.

Anyway, I’m working on expanding the thin campaign layer a little bit  at the moment as a change of pace from the tactical battles code. I’d found myself struggling to get back into the programming while I was working on the tactical battle path finding for whatever reason but the grate thing about indie game development is that if you get burned out you can try coming at the game from a different angle for a while (there is always plenty of work to do). So I drew and painted up some little building icons and I’m now re-factoring the existing morass of the campaign layer so I can squeeze them in on their own screen.

The idea is to introduce more and more systems that feed into one another, so the buildings will be built and upgraded with gold and prestige that you earn from completing contracts and they will in turn unlock more ways to improve your mercenary specialists, boost your prestige and add more ways to earn gold. I guess the goal is to one day have something as satisfying as building your base up in X-Com or improving your towns in a HOMM-alike game. For now it’ll be fairly simple though, columns of little icons and descriptions.

After that I may pirouette back to the tactical battle code I was working on before, which was the rather tricky process of adding penalties for trying to disengage from, and move through melee combat opponents. Right now one of the most effective tactics in the tactical battles is to run away from an opponent for half of your allowed moves and then charge back in to get a charge bonus every turn. Obviously that is a bit ridiculous and not the tactical game of positioning I’d like to move towards. Instead I’m going to allow a free ‘unopposed’ attack on a mercenary that tries to move out of  hex adjacent to an enemy. Sounds easy enough but it means I have to rework the movement interface and logic for this special case to a) allow the unopposed attacks to be shown and b) to indicate to the player that he is about to make a special kind of move that he might want to think carefully about. I also have to change the regular A* pathfinding code to avoid including this type of special move in the middle of a normal path, instead it will attempt to give enemies a wide berth unless you specifically ask to attack them or otherwise enter their threat radius.

 

 


Lords of the Burning Hells

 

This year my regular work invigilating the school exam season coincided with the release of  one of my most nostalgically anticipated games; Diablo 3.  Suffice to say the combination of these two activities has kept me from much substantial development work for the past month, but bills gotta get paid (and Diablo gotta get played?).

I wonder sometimes if I might ever have got into game development if it wasn’t for the Diablo series, the original game and eventual it’s sequel introduced the barely teenage me for the first time to to the internet culture around games. I spent many hours engaged in crafting websites for guilds, getting involved in ridiculous guild politics and even knocking up micro fansites for speculating about Diablo 2 news and lore.

I recall that it was through a chat with an acquaintance of my Diablo era obsession that I first heard about some upcoming game called Half-Life that she thought might be the next big thing. Which for my convoluted path to proper  game development, via modding and QA, it definitely was. The atmospheric design of Diablo and it’s randomly generated levels were also a key design inspiration for Free Company. If I wanted to shorthand describe Free Company to someone  I might be tempted to say X-Com meets Diablo and Baldur’s Gate by way of HOMM (on acid).

So, Diablo 3 has a strange pull on me for those reasons even if for other, ethical and pure design reasons I have come to regard the core Diablo design as something to be slightly dubious of. Long term readers of this blog might recall me expounding on this a while back  but the short version is that the loot reward mechanic at the heart of most ARPG type games is uncomfortably similar to slot machines and inspires similar addictive behaviour that may or may not have a relationship with actual fun. Actually, Diablo 3 takes this slot machine analogy a step closer by allowing you to immediately and directly sell the items that pop out when you kill a monster for cold, hard cash.

I’ve been playing a lot of it regardless, and they have actually added a bunch of cool design things ontop of that core gambing mechanic that I’ve really liked. The best new thing is undoubtedly the deck building-alike skill system where you can have a ‘deck’ of six active skills  picked from a library of around a hundred possible individual skill variations (a smaller range of actual skills that are then each modified by a list of 6 so called ‘runes’, the modifications vary from tiny to dramatic). What this means is that instead of having to start a new character each time you want to try out a new skill as you had to in previous Diablos (and many other roguelikes) you can just hop over to a drag and drop menu and switch out the skill and have the best possible version of it without needing to spend hours carefully hoarding skill points or any other nonsense. It is a great change that allows you to creatively attack challenges when the game becomes too difficult or too stale.

There is some question as to whether or not all the available skills are equally balanced for the challenges of the endgame but there will be patches down the line and for most of the playtime you put into levelling up your character the skill system allows you plenty of freedom to experiment and just enjoy the full range of things your character type can do.

The other great improvement comes from the careful application of physics and animation to convey a feeling of solidity and power to your characters every movement. It’s hard not to enjoy the feeling of thwacking a zombie with such force that he flies across the terrain, smacking into obstacles as he goes, and Blizzard have got it just about perfect. Making every click as satisfying as possible is really important in a game where you are going to be doing a heck of a lot of it.

Anyway,  exam season is drawing to a close next week so this blog should resume it’s regular, irregular update cycle of progress updates on Free Company shortly. I totally programmed a function before writing this just to see if I still remembered how code works. Luckily, I did.


Improved Furnishing

warehouse storeroom

click to enlarge

 

Recent work on Free Company has been focusing on improving the look of the randomly generated rooms by subtly shaping the way the objects are laid out to conform to more human norms of laying out rooms. For example shelves in the game are now no longer empty instead they are filled up with appropriate small objects . The objects as redetermined by the procedural generator-wide tagging system. Objects have tags; levels, monsters and rooms have tags; the generator attempts to assign them to each other using probabilities based on how closely the tags of each align. The way the objects are placed on the shelves is determined by three different algorithmic approaches that attempt to mimic general human behaviour as regards shelves: filling up from the left hand side, from the right hand side and alternately from the left and right hand sides. The quantity of objects on each shelf is determined by a normal distribution linked roughly to the dimensions of the shelf to ensure that the average shelf is about 90% full .

That’s one example, other new strategies have been employed to shape the placement of the shelves themselves and other objects to create the hopefully more believably storeroom like rooms you see in the screen shots on this page. To support these new furnishing algorithms I’ve also been making a whole pile of new objects, almost doubling the number of them in the past week. Some of these can also be seen  in these two shots.

 

click to enlarge

 

The basic warehouse layout and furnishing algorithms are probably done about as far as I am going to take them for the first release all the rooms now look passable and I expect I can reuse the same algorithms for a few other environment variants like the crypt and a new library layout once I create a few more objects to support them. I still have plenty more ideas for algorithmic level generation though and I’d love to revisit this area to try and  make even more believable and varied layouts in the future.

The other new things I’ve done  recently are a few minor cosmetic buffs. From feedback to my last post (thanks Stian!) I’ve switched out the general game font for a more serif ridden fantasy one, I’ve fiddled with a few of the most frequently seen textures to try and make them a little less bland (still a work in progress) and I’ve implemented a more flexible system for testing out lighting changes quickly in game (hit a key to rebuild the lights from the theme data .xml files). The last thing (which just went in today) has allowed me to fiddle with small lighting changes and see the result in a couple of seconds rather than the many minutes it was taking before, so I updated a few of my lighting themes with some tweaks too.

 

Anyway, as usual let me know what you think about the Storerooms or anything else in the post in the comments below.


HUD improvements & Memory leaks

click to enlarge

This fortnight has been spent plugging all the memory leaks that had built up in the Free Company code base since the last time I went through and plugged them all. The work was considerably eased this time by the use of a new tool I discovered called Visual Leak Detector which makes the process of pinpointing where the leaks are happening fairly trivial by providing callstacks. It also runs fairly quickly in the background so I can leave it on permanently in debug builds to continue passively identifying new leaks as and when they spring up. VLD is super simple to integrate into any project as well so if you are still struggling along with C++ out there I recommend adding it to yours immediately. The only thing it doesn’t catch are Direct X memory leaks for which a more traditional approach, and the debug runtime, is still needed.

Once all leaks were deftly disposed of it was on to a HUD tune-up, something which is still ongoing and probably will be right up until the release. You can see some of the results of the changes in the screenshot above. I was aiming for less numbers & more visual ways of showing what is going on, as well as adding more widgets to give you better control over your whole party of mercenaries. The portraits added back in January now provide a handy way to select a particular mercenary and jump to his current position in the world, and they will  also soon contain a shrunken down overview of the bars on the main HUD for each merc. There are now special pointers for all of the various ways you can control the camera which possibly only I care about. Finally, I spent a bit of time tweaking the colours of various elements to tie the buttons into the HUD better, improve consistency between different elements and generally reduce the ‘primary’ nature of most of the colours I was using before. I’m still not very happy with the layout of the bottom HUD area ( a lot of spare/wasted space, the elements are a bit boring) nor the fairly crappy skill icons but it is coming along all the same.

click to enlarge

While I was fiddling with the HUD I also went through and ticked off a whole heaving heap of bugs with the skill system so that the handful of currently implemented skills now actually work properly all the time and give slightly better feedback when they are being used to boot. Implementing a host of new skills and improving their feedback is one of the big upcoming tasks so I wanted to have the ground prepared for when that is started. And as a final thing I’ve just now tweaked the post effects again to add a vignette.

To give a sort of general picture of where the game is at I have about a week or so’s more tasks listed on my current ‘polish’ to do list to get through before I start on one of the big three remaining tasks pre-alpha release. Those big tasks are; skills, AI & real-time play between combats. I’d welcome any feedback on the changes/look of the HUD in the comments. Or really, any comments at all. Speak your brains internet.

 


Lightmaps, ESM & Fog of War

Click to see giant version

Progress on Free Company continues at a steady pace here in the shed, unfortunately I’ve been pretty lax about reflecting that progress on the blog but no more for today I come with tales of newly implemented features, bugs fixed and graphical systems steadily improved.

First up is the new fog of war system. I spent a fairly long time with the implementation of fog of war sitting at the bottom of my many & various scrawled to do lists. I knew I wanted it in the game but I wasn’t quite sure how to get it working and running at a decent speed. The first problem is that there was no obvious example to be ‘inspired’ by, most games that I could find using fog of war were either fully 2D or they didn’t combine it with a fully rotate-able 3d camera. I needed a solution that obscured a given hex from all possible angles when none of the mercenaries could see it. I also wanted to be able to have a semi transparent view of areas that the mercenaries had already visited.

Anyway, as you can just about see above I managed to figure it out by using sort of hexagonal cages that are rendered over the top of the level geometry, and then using a complicated blend mode to do the semi-transparent version without showing the sides of all the neighbouring cages. It isn’t quite perfect as there is only a subtraction operation available to do the ‘transparency’ rather than the normal multiply but it works passably enough and most importantly isn’t horrifically slow.

The blend modes look like this:

 HR(g_d3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE));
 HR(g_d3dDevice->SetRenderState(D3DRS_SEPARATEALPHABLENDENABLE, TRUE));
 HR(g_d3dDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_REVSUBTRACT));
 HR(g_d3dDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_DESTALPHA));
 HR(g_d3dDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE));
 HR(g_d3dDevice->SetRenderState(D3DRS_SRCBLENDALPHA, D3DBLEND_ZERO ));
 HR(g_d3dDevice->SetRenderState(D3DRS_DESTBLENDALPHA, D3DBLEND_ZERO ));

…just don’t ask me to explain them because I did it a month or so ago now.

After I got the fog working I spent a fair bit of time improving the intuitiveness of some of the UI elements so now the sliders and scroll bars work more like proper scroll bars with live updates (change the music volume in terrifying real-time!!) and the buttons have proper embossing so they look like buttons. I also fixed a whole bunch of tiny pixel offset problems with things like the text and the basic ui rectangles that were causing some slight (but noticeable) visual problems.

Next up was implementing a new lighting technique called light mapping. This was a bigger project than I’d hoped at first glance to fix a small visual problem but now it is done and as a result I have a bit more flexibility with lighting. The basic problem I had was that my static geometry (which covers all the walls, floors, shelves and so on) could only support being affected by three lights simultaneously. On older graphics cards I wanted to support there was simply no way to physically pack any more lighting data into the vertex buffers or into the shader instruction count if I switched back to slower dynamic lighting.

At first, I’d tried to alleviate this problem by keeping the lights in any given generated room under three which worked to an extent but inevitably the random generation meant that occasionally a light from a corridor adjacent to a room would  push the number of lights affecting a mesh over three and there would be obvious lighting discontinuities. I tried implementing a range of simple ‘light blockers’ to reduce this problem further but those didn’t really help as they had no way of dealing with a mesh that was lit from more than one side (such as the very frequently used room corners). So, I either had to put up with the lighting discontinuities (they were of variable severity but in the worst case there was wildly different colour lighting and brightnesses on each adjacent wall mesh) or I had to come up with a new lighting scheme.

There are two basic approaches, the modern and the retro. The modern approach involves using deferred rendering for basically everything and is slowly becoming the approach that all modern engines are moving towards as it has the most flexibility and the least disadvantages. Unfortunately, in my case this problem was being caused by trying to support older graphics cards in the first place. It isn’t much of a solution to switch to deferred shading and cut out all those old GPUs which don’t have the necessary oomph to do deferred shading. So I was left with the retro approach, which is lightmapping.

click to show giant version

Lightmapping isn’t an ideal fit for my game because it is principally a pre-computed technique and gets most of it’s advantages from being able to take advantage of known geometry arrangements in the data building stage and then spend as long as it likes crafting really fancy lighting setups for them. However all my geometry layouts are generated on the fly each time the player starts up a new level. I don’t have the time to do a expensive set of ray-traced lighting calculations while a player is sitting there waiting for the level to load. Luckily however, you can make the lighting calculation as simple as you like when generating light maps so I set the dial to ‘super-simple’ and set about getting them actually working.

Lightmapping as a technique actually contains several smaller problems that need solving;

  1. generating light mapping UV coordinates.
  2. packing lightmapping UV coordinates of all the instances proportionally to the surface area being lit.
  3. interpolating the positions & normals of all the mesh instances.
  4. generating the actual lighting data
  5. rendering with lightmapping.

The last part is the easiest, if you’ve done it all right you can just read in your lighting from a texture with your specially generated UV coordinates. The other parts, were not so simple.

For the first part I decided to create my lightmapping UVs as part of my models’ mesh data rather than algorithmically generating them. Mainly because this is one of the few steps I could take ‘off-line’ but also because I, perhaps foolishly, thought it might be easier to make them this way. I used blender to generate my UVs and if you do the same let me give you the most useful tip straight off; the blender ‘lightmap UV’ generation script is pretty much useless for complex geometry. By which I mean any curved surface, if you don’t have infinite space on your light maps you are going to want those curved surface UVs stored contiguously in your lightmap so that the sampler can smoothly interpolate across the surface. The blender script, by contrast, breaks up every face into separate uv ‘islands’ and then tries to pack them in any old order, bah.

Anyway, I also had another problem to overcome with UV coordinate generation, mainly that the only decent .x exporter script I managed to find for blender 2.49 didn’t have any support for multiple UVs and secondly the .x format itself makes it very difficult to work out how to cram extra data beyond the basics into your meshes. Once you do work it out it is excruiciatingly difficult to convert the data into the required (DWORD) format in python. You will need this piece of code:

def convertFloatToDWORD( self, float ):
 pF = ctypes.pointer( ctypes.c_float( float ) )
 pDw = ctypes.cast( pF, ctypes.POINTER( ctypes.c_uint ) )
 return pDw[0]

(from here) if you want to have a chance.

Part 2 of the lightmapping problem wasn’t quite as difficult, I used a very simple rectangle packing algorithm on the basis that that would probably be fastest and scaled each instances UV rectangle by the surface area of the asset calculated during loading. Make sure to keep track of the calculated UVs somewhere as you’ll probably want to pack them into your static geometry when you batch it up.

Part 3 was more tricky and after stumbling around with the semi-missing code at flipcode for a while I hit on barycentric coordinates as the interpolation method of choice which seemed to produce the nicely smoothed normals I was looking for and was a whole lot less code too:

//calc normal
 D3DXVECTOR2 edge0 = faceCorner2uv - faceCorner0uv;
 D3DXVECTOR2 edge1 = faceCorner1uv - faceCorner0uv;
 D3DXVECTOR2 edge2 = uv - faceCorner0uv;
// Compute dot products
 float dot00 = D3DXVec2Dot(&edge0, &edge0);
 float dot01 = D3DXVec2Dot(&edge0, &edge1);
 float dot02 = D3DXVec2Dot(&edge0, &edge2);
 float dot11 = D3DXVec2Dot(&edge1, &edge1);
 float dot12 = D3DXVec2Dot(&edge1, &edge2);
// Compute barycentric coordinates
 float invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
 float u = (dot11 * dot02 - dot01 * dot12) * invDenom;
 float v = (dot00 * dot12 - dot01 * dot02) * invDenom;
 float w = 1 - u - v;
worldNormal = (faceCorner2normal * u) + (faceCorner1normal * v) +
 (faceCorner0normal * w);

So use those for everything interpolation related.

The lighting code I already had, though it is worth bearing in mind that by implementing lightmapping the sum total of your lights will probably be saturated from 0.0 to 1.0 by the necessity of texture storage. Which doesn’t sound like much of a big deal but it can make a pretty noticeable difference when you are summing up the influence of multiple point lights and then multiplying that by other lighting terms in your shader.

Anyway, eventually after a lot of careful hand crafting of UVs that was all finished and now I can have as many lights as I like per room without fretting too much and all the discontinuity artefacts are gone. Aces.

Next up on my lighting refactor mission was the shadow mapping code. It’s been working OK for a while now but has always showed some ‘shadow acne’ at certain camera angles and, worse, the acne shimmered whenever the camera was moving immediately drawing your eye to it. I spent some time tweaking the current code and fiddling with bias values and resolution but no matter what I could never satisfactorily remove the shimmering acne. So, I figured there must be another way by now.

Of course, some careful googling later introduced me to the world of Variance Shadow Mapping (VSM) and Exponential Shadow mapping (ESM). This blog was a great summary of the best places to learn about each technique and really they aren’t dramatically different from shadow mapping. Once you have basic shadow mapping setup in your game it is no more than a morning’s work to try out both VSM and ESM I would recommend everyone struggling with shadow mapping artefacts give it a go and then probably settle on ESM because, at least for me, the light bleeding artefacts with VSM were pretty obvious and just as bad as shadow acne. ESM however immediately worked great and cured my shadows of acne, tedious bias tweaking and shimmering. I do have one difference with the blog linked above in that he mandates keeping the over-darkening parameter to between 0.0 and 1.0, I found by contrast that the original range specified in the nvidia example worked a lot better in my game so don’t be afraid to crank that term up.

Lastly, the past day I’ve been fiddling with improving the SSAO term. I’ve not totally settled on a method yet but so far I’ve replaced my basic box blur with a ‘bilateral’ version that respects normal and depth discontinuities and had a stab at sticking this new fangled FXAA on top of that so it’s jaggy edges don’t completely ruin my lovely regular MSAA rendering. Not totally sure that the FXAA is completely working but eh I might come back to it later.

Anyway, that is probably enough lighting stuff for now as I’ve reached the bottom of the lighting to do list. Next week I’ll likely start by tackling a whole range of bugs and minor polish problem and then it’ll probably be back to either skills & related UI improvements, better AI routines or realtime group movement between battles.


You make me sad with your eyes

some portraits I dun hacked together

 

A long time with no blog updates, but things have still been happening on Free Company.

 

Since the last time I’ve implemented a new combat – framework? I guess is the right word, that evaluates combat attack success based on how much ‘energy’ the defender has left, as well as things like attributes, skills and equipment. At the same time unsuccessful attacks have been changed so that they do damage to this new ‘energy’ concept proportional to how powerful the attack was. The idea behind this self reinforcing system is both to speed up combats by quickly driving home an advantage to the likely eventual winner and also to make all attacks actually change something within the game. At the same time the concept of health has become a lot more granular and a lot more scarce, most horde type enemies will only have a single ‘wound’ now and mercenaries will have to train to get extra wounds if they want to survive prolonged combats (I’ve yet to decide how many to start them with but I’m leaning towards two).

 

This has been quite a big mechanical change so it’s detail will no doubt continue to be refined and its unintended consequences explored as the development goes on but for now I’m happy that it is better than what was there before with long grind fest combats, chipping away at health bars and having completely wasted rounds due to a couple of crappy dice rolls.

I’ve also been spending some time improving most of the UI widgets based on some feedback from my tiny play test team (thanks bro). This has involved exposing more previously hidden information, adding more tool tips and fixing problems with open UI panels not being updated when the world state changes around them. Half of the battle with designing a game is explaining to the players what is going on in a clear enough way that they can make good decisions. I’m sure this battle with explaining the design through the UI will continue until I stop working on the project.

As well as improving the information content of the UI I’ve also embarked on a mini art splurge to try and improve the looks of a few bits of it by drawing some generic mercenary ‘portraits’ for use on the character sheets, in merc lists and possibly in a future group selection UI.

Other than that, I’ve been dual-classing again this month; doubling up as an exam invigilator when I’m not working at home on the game. Hopefully these vital pennies will help continue to fund my itinerant lifestyle of reckless game development and finally get this game finished.

 

Christmas happened too. I miss it already. Sort of.