Excited about Celetania? I am!

First of all, go check out World of Goo, which was just released for Linux. Alright, now on to the rest of this post…

I recently quit playing Travian, a persistent-world web game where you created your own medieval empire. I won’t go into all the reasons, but suffice it to say that there were balance issues with larger player swallowing up newbies and ruining their play experience (not that I was one of these newbies, of course).

As I understand it, there are a number of persistent-world games out there (games in which the world continues evolving while you are not present and playing). I haven’t spent enough time looking into other titles, so Celetania was able to completely capture and hold my attention.

http://celetania.com/

So why am I so excited about Celetania? It has quests! If the way I assume they work is right, they have the potential to eliminate the balance problems between players of different skill levels. I don’t like picking on Travian exactly, but it’s the only game I’ve played like this, so I’ll use it for comparison. In Travian, there are no quests, and no “safe zones” for newbies. It is a common strategy for larger players to attack and “farm” smaller players for their own benefit. How to quests help?

If done properly, quests may give greater rewards for larger players than attacking small players, thus making it a better use of your time to pick on people your own size. I assume quests are adaptive to a player’s size, so they also give small players a chance to expand safely.

Anyway, that’s all for now!

Common alpha-blending problem

So a while ago I tried to convince myself that I’d start blogging more. I told myself that I’d stop caring about post quality and just write because I want to write. Obviously, I care more about quality than I had thought…

Now on to something useful. I’ve been wanting to write this post for a little while…

A number of open-source games I’ve played put emphasis on various lighting effects. For whatever reason, quite a few of these games don’t use an additive blending mode for these effects, choosing instead to blend the image based on opacity. If you have no idea what I’m talking about, just take a look at the image below.

As you can see, additive blending takes the values and adds them together, whereas normal blending based on opacity averages the two (as a side note, I have no idea whether these are official terms or not). So how does this matter in games?

The problem arises when textures intended to be overlayed with the additive effect are blended according to an alpha channel that is generally created by creating a grayscale version of the original texture. The alpha channel for an explosion looks something like this, then:

As you can see, the in-game image lacks vibrancy and doesn’t feel “hot”. This is mostly because the alpha channel is blending the center of the explosion with the background. Most games don’t settle for these results, and brighten the alpha channel to look like this:

This explosion looks a lot better, but now there is a dark ring around it. This is caused by the fact that the outer pixels of the image are not being blended as 10% red/orange, but 10% dark red/orange. Here is the solution I’ve found so far:

Making the background red has eliminated the dark band, and bumping up the brightness in the alpha channel prevents the explosion from being dimmed by the background.

Now, you might say that “it looks just fine without the red background! The dark ring adds contrast and hints at ash or smoke.” If that’s what you’re going for great, but the red-background version fits into the game better without popping out of the scene, and ash/smoke should fold around the form of the explosion and not remain simply around the edges. An explosion against blue sky only emphasize this problem.

Besides, this problem doesn’t apply only to explosions. Laser blasts, lens flares, etc are all vulnerable to having dark-alpha edges. With a little work, however, your opacity-blended effects can look almost as good as additive ones!

One rumor true, lets start another!

If I remember correctly, a while back there was speculation that Amazon.com might open a gaming platform to compliment their other services. Now it seems these rumors were correct. Joystiq and Shacknews report that Amazon has opened a game store with prices ranging from $6.99 to $9.99.

I’ve wanted someone to open a Steam-esque Linux game store for a while. While their downloader software “currently supports Windows only“, we may remember that their MP3 downloader utility is available for many of the popular Linux distributions. Time for crossed fingers?

Maybe. From what I gather, this service is the result of Amazon’s purchase of Reflexive. While I’m not giving up hope yet, it does seem that Reflexive’s previous efforts involved (predictably) only Windows and Mac OSX.

Still, we can dream can’t we?

Then again, perhaps a service like this already exists?