Last December I finally finished my Master’s thesis for the Game and Media Technology programme at Utrecht University. It was more arduous than anticipated, but I’m satisfied with the result.

The topic of my master thesis is real-time high-quality global illumination. In short, I developed a radiosity-style technique which modifies the radiosity solution using hemicubes which are rendered only from the perspective of the dynamic object. Real-time high-quality diffuse global illumination is achieved using this technique, but only for relatively small scenes. Although my implementation is not suitable for general use in games, I’m convinced the theoretical framework introduced in my thesis has a lot of potential and will lead to more practical techniques when investigated further.

The thesis, which provided me with a cum laude graduation, will appear later on this website under “Graphics Research” together with a demo.

This movie shows the results, which was captured in real-time on an AMD Radeon HD 5770 graphics card. The visual quality is nearly indistinguishable from the reference rendering.

Development Break

I’ve been quite inactive on the development front, but for a good reason. I’m currently creating (and going to teach) a master’s course in Advanced Graphics (technology) at the Utrecht University. More information can be found here:

The teaching is a one-time thing which will be finished at the end of April. Aside from being really cool, the teaching will provide me with some healthy financial reserves. I will use those reserves when starting full-time independent game development.

I haven’t been totally inactive on the development front, but most of my time is spent refining concepts and making plans for the future. There’s some really cool stuff coming up, but it’s too soon to talk about it…

Game definition revisited

One of the things I hate about writing on a blog is that I’m always confronted with my earlier thoughts. The previous post has been up here for over 3 months, but my opinion changed 2 and a half months ago.

My new standpoint is that the word game actually has two commonly accepted meanings. There’s the meaning based on Wittgenstein’s analysis which states that a game cannot be strictly defined (and thus nearly everything can be a game). The other meaning is used in a ludologist context. Most game design research is done in the context of rulesets. When looking at games from that ludology angle, it is sensible to define “game” more strictly. All games which do not consist of rulesets are not interesting from that point of view, because the ludologist’s methods of analysis do not apply.

So the next time someone tries to exclude something from the realm of games, I can rationalize their opinion by accepting them as part of the ludology school of thought.

My game should not be a game

What I didn’t realize before is that the label “game” is not always positive. Many of the non-gamers in this world do not like the focus on challenge which is present in most games (especially casual games). This can be because they do not like to lose, but also because they are just not interested in artificial challenge. This group will not play a game for the sole reason that it is called a game.

The games which have their label disputed are often not challenge focused. These would be perfect for the non-gamers discussed above, but giving the games the predicate “game” actually deters this audience!

What would be a better name, then?
“Notgame” is sometimes used. That name is based on the notgames initiative (led by Tale of Tales). This name is not familiar with non-gamers unfortunately, but it could be a start. However, I feel this name is not applicable to my games. From what I’ve seen notgames are generally focused on atmosphere/narrative/deeper meaning, while my games are primarily oriented on play (without the focus on challenge). (The terms used in the previous sentence are very vague, so they might not describe exactly what I mean.)

The main question is still open: what would be an appropriate label for my “games”?
Ideally, I’m looking for a term without “game”, while still being reasonably specific (e.g. not “experience”).

Help! My game is not a game

As a developer of experimental games, it can occur that someone states that your game is not really a game. Instead, it’s a toy or an interactive *something*. While this may come from a good heart, this is probably not true and you know it. There is a reason why you’re calling yourself a game developer and not a toy developer.

It can be hard to defend yourself against such a statement. The what-is-a-game discussion derails easily due to differing or vague definitions. In this post I will describe a strategy to counter an attempt to exclude your game from the class of games.

Level the Ground

The person who is making the claim that your game is not a game (from here on called the accuser) will probably have a strict definition of the term game. The first thing to do is to establish a ground truth. The ground truth in this case is: If everyone calls something a game, then it must be a game. (Note that “everyone” is not to be taken literally, it is meant as the majority of people.) This is inherently correct because of the way natural language works. Natural language is based on the common agreement of the meaning of words.

Take as example the word cool. It used to have the strict definition of being cold. However, through mass use it gained the additional meaning of something that is “fashionably attractive”. This shows that the common use of a word determines its meaning. A definition can be formulated to capture this meaning (although this is not necessary).

Using the ground truth we can verify for popular games that they are indeed games. We’ll look at game websites and game development awards to find confirmation that they are really games. If a game is featured by several of these websites (and treated like a game), we can be sure that the majority of people also see it as a game.

Build Towards Your Game

Chances are that the game in question (your game) has not received enough public attention yet to be able to use the above approach. Instead of directly proving that your game is generally seen as a game, we’re going to use the act of deduction. Pick a popular game which is very similar to yours. We can verify that it’s truly a game. But if your game would not be a game, then the “gameness” would have been lost in the differences between your game and the popular game.

To complete the argument, we first ask the accuser in which exact difference(s) the “gameness” was lost. For each suggested property, we’ll have to find a counter example – a popular game which does contain that property. For example, if the disputed property is challenge we can present the following counter examples (generally accepted games which do not feature challenge): Proteus, FarmVille and even RPG’s which largely rely on grinding. And for the property goals we can refer to Minecraft or The Sims.

If the game you used as counter argument is suddenly also not a game, it is easy to verify that it’s truly a game using the method described above. Also, make sure that there is a clear definition of the property being discussed. Anything can be seen as (for example) challenging depending on your perspective. So if the accuser argues that your counter example does contain challenge, you can take a perspective which includes your game as well: the mere act of walking in a game is already challenging for a lot of non-gamers.

Finish Him

The accuser might still be unable to accept that your game is really a game. The reason is that his definition of a game simply does not adhere to the common usage of the word game. You could say that either his definition of the word game is wrong, or that the category of games he’s trying to define should have a more specific name than just “game”.

I hope that this strategy does not only help you to prevent the exclusion from the class of games, but also that it strengthens your confidence that you are making real games.

Reprojection experiment

I was just playing around with this strange idea I had. When walking around, the old image information is recycled to compose the new image. That is, until you press a button to refresh the information for your current position.

Can you get a feeling for where you are in the environment?
I’m not sure what I will do with this. I have several ideas to turn it into a game, but I’ll have to investigate what works best.

(Model is the public domain Sponza model, by Crytek.)

Porting a 3D XNA game to the Mac using MonoGame

When making a cross platform game, XNA is generally not a good choice because it depends heavily on the Windows-only .NET framework and DirectX. In my case, the Mac OS X port came as an afterthought. After creating the game Seven Dimensions for the 7 day FPS challenge, some people requested a Mac version. I thought it was impossible to recompile an XNA game for Mac OS X, but a friend of mine said it could be done! I decided to go for it. If it worked,  it would make XNA a lot more versatile.

Step one: Get a Mac

At first I tried to use Mac OS X in VMware. Running Mac OS X was surprisingly easy, thanks to a pre-made solution found on the internets. But I didn’t succeed in running any type of 3D game at all. I guess the VMware graphics driver can’t handle slightly more complicated graphics. On top of that, Xcode seemed to be impossible to install. Fortunately, I could borrow a Mac from a friend.

Step two: Setting things up

There’s an excellent guide here (part 2 here) which describes everything you need to download and install. However, that guide is aimed at 2D games (using SpriteBatch only). There are some small differences if you want to use 3D graphics with custom shaders. Most importantly, you need to use the develop3d branch of MonoGame (at the time of writing).

Any shaders you want to use have to be compiled into an intermediate MonoGame format. To compile the shaders, you need a Windows computer. Open the 2MGFX solution found in the develop3d branch under Tools. This solution depends on additional dependencies which you have to download separately. Go to the develop3d branch of the github repository and go to the ThirdParty folder. Click on the green “Libs” folder, download that as a zip file and place it in your local ThirdParty/Libs folder. Now you should be able to compile the 2MGFX solution. The compiled program is the command-line tool you have to use to convert your .fx shaders to .fxg shaders. Make sure to open the .fxg shader in a text-editor to see if there is shader-like code in there.

You should test your setup using the CartBlanche sample Particle3DSample. If it compiles and runs without crashing immediately, you’re ready to port your game.

Step three: Porting your game

Prepare your project as described in part two of the guide mentioned above. Your code should compile almost directly. But unfortunately, you will encounter problems when running your game. The problems are very project-specific. These are the problems that popped up in my project:

  • The Game class was destroyed instantly causing an exception that the Game class was used while it was disposed. It turns out that Mono handles the “using (game = new Game())” syntax  in program.cs differently. Simply rewrite this code to avoid the “using” syntax.
  • EffectParameters were not found. This can be caused by two things. First of all, if a parameter is not used in the effect, you can’t set it. Secondly, texture effect parameters cannot be found. The texture should be set using the texture sampler EffectParameter instead.
  • The sampler settings defined in the shader were lost. You should set these settings from c# using the GraphicsDevice.SamplerStates collection.
  • The Mouse.SetPosition function does not work. I worked around it, maybe it’s fixed in a later version of MonoGame.
  • The viewport position offset was mirrored vertically. This is easily fixed by correcting the offset of the viewport you create.

Step four: Hope for the best

MonoGame uses OpenGL instead of DirectX, which can cause obscure problems. Your game might behave strangely on some hardware for no clear reason, especially if you use uncommon graphics features. Seven Dimensions uses line-drawing in combination with depth testing, which is very uncommon. The depth testing didn’t work for the line drawing, so I had to rewrite the game to use triangles instead. There are still other problems on older hardware which I haven’t been able to solve yet.

In total, I spent one day (8 hours) on the port. That’s very little considering that most time was spent on figuring out how to use MonoGame for 3D. The resulting port is not perfect, but MonoGame is still in active development so it will only get better!

Presenting: Seven Dimensions

Seven DimensionsThe seven day FPS challenge is over, and my game is finished! It could be more polished, but I’m really happy with it considering the time constraints.

Seven Dimensions is a puzzle FPS where you play in seven dimensions simultaneously. Is your spatial reasoning capable of understanding these strange worlds?

Go to the page of Seven Dimensions.


I’ve joined the 7DFPS game development challenge. The goal is to make a non-traditional FPS in seven days. This post also appeared here at the 7DFPS website.

A 7 dimensional FPS has been suggested by several people on the twitternets, but no one seemed to be serious about it. As if it couldn’t be done… That touched my Barney-Stinson-button so I immediately said: Challenge Accepted. (With the really serious face.)

After investigating seven dimensional space for countless hours (30 minutes), I found that it is quite an exceptional space. Several calculations defined on 3D spaces are also possible in 7D, but not in the dimensions in between them. The 7D cross product is defined, and octonians can be used for rotation (similar to the quaternions for 3D). Then I watched this video on youtube, which shows a rotating cube in 7D. It struck me that the seventh dimension is really ludicrously insanely difficult for a human to understand (Yes, that difficult). Let’s first see if Miegakure will succeed in explaining the fourth dimension before starting with a higher dimension…

Because failing the quest for a 7 dimensional FPS is not an option, I decided to look at it differently. If I could lower the complexity by decoupling some of the dimensions, it might be possible to make something that’s actually understandable! I decided to decouple the space to 4 separate worlds, three 2 dimensional worlds and one 1 dimensional world (2+2+2+1 = 7). Is this cheating? Well, a little bit… My game doesn’t offer the full complexity of the seventh dimension. But on the other hand, 7DFPS is about making fun games and the seventh dimension wouldn’t be fun to play in.

Now I just have to make one 1D world and three 2D worlds. Easy right? But wait, it can’t be a normal game with 2D graphics, it has to be 2D in first person. How does that work? A 3D FPS has three axes: width, height and depth. For a 2D first person perspective, one of them has to be ditched. The depth cannot be removed because that’s necessary for the first person perspective, so it’s either width or height. Removing the height seemed like a sensible decision so I went with that. Now there’s still the 1D first person perspective left. There’s not really a choice but to remove the width as well. So the 1D first person perspective has only depth. Okay WTF?? Time for a screen shot.

7 Dimensional FPS Concept

That’s how it looks like at the moment. The 2D worlds have no height, so they are just a line (scaled a bit to make it more visible). The 1D world doesn’t even have width, so it’s just a dot (also scaled for visibility). It’s very hard to get a sense of depth from these images, but it gets much better when you start moving.

There still has to be some sort of shooting game in these weird worlds… Let’s keep it simple, because we don’t want the player’s brain to explode. What about hitting green targets, and not hitting red targets? You move simultaneously in all four worlds, so you’d have to be careful not to hit a wrong target in a world you’re not focusing on. It would be more of a puzzle game than an action game this way.

This puzzle concept is also a great opportunity to make the 1D world useful. Because you can’t rotate in the 1D world, your shots will always hit the closest target. If there are five green targets and one red target at the back, you can only shoot five times (simultaneously in all worlds) because your sixth shot would hit the red target in the 1D world. This can be used as a sort of natural ammo system. If each 2D world has one green target (3 in total) and if you would have only 1 green target in the 1D world, you’d have to hit all 3 green targets in the three 2D worlds with one shot.

Curious how this will turn out? Follow my progress here, on my twitter, or on my blog.
Have any questions/feedback? Please let me know!

A game without challenge. Why?

GTA IVMost games focus on a challenge the player has to overcome. Maybe because of this, the general consensus seems to be that challenge is the core of a game. But when I look at some exceptionally entertaining games, such as Grand Theft Auto IV and Minecraft, challenge is not the part that makes them fun. In Grand Theft Auto, I mostly enjoy the presence in a different world (escapism). For Minecraft, creation is the main reason I stay interested. Apparently, challenge does not have to be the ingredient that makes a game appealing. In fact, I think challenge can even hurt the game. The missions in Grand Theft Auto focus on increasingly difficult challenges, which actually drove away my interest in the game. I think the game would have appealed much more to me if the missions would have accentuated my freedom in the digital world (not necessarily through something challenging).

If challenge does not necessarily make a game fun and it can even hurt the experience, would you need any challenge at all to make a fun game? By removing challenge, it cannot distract the player so he might be able to experience more fun! But there’s a problem: it’s not possible to remove challenge completely. Interacting with the game is always challenging at some level. The easiest one-button game is still a challenge for a baby. Instead of trying to remove the challenge, the challenge should be reduced to a minimum. Preferably to such a level that the player will not perceive the challenge as an obstacle.

Guitar Hero 3Without challenge there should be another way to make the game interesting. For A Sense of Music, I focused on the musical trance that can be felt sometimes when playing music games intensely. I had this very pleasant experience a few times when I played Guitar Hero. Unfortunately it suffered from the constant pressure to keep hitting the correct buttons. My plan was to remove the fixed button layout and the time pressure in order to increase the focus on the musical trance experience. Would it work? To play the game, visit the website of A Sense of Music. I will discuss my findings of this experiment in a later post!