Alien Arena is an open sourced game that combines a sci-fi atmosphere with the tournament style deathmatch of Q3A and UT2k4. Major graphical features such as GLSL per-pixel lighting, ragdoll physics, light blooms, real time lights and shadows, textured particles, shaders, and reflective water, create a colorful and immersive deathmatch atmosphere. The game also includes mutators, adjustable effects, bot skill settings, and fully configurable deathmatch, team deathmatch, CTF, All Out Assault, Team Core Assault, Cattle Prod, and Deathball games. The game features original artwork, with a dark, sinister atmosphere combined with an off-the-wall campiness, and trippy, techno type music. There are currently over 60 maps, loaded with weapons(each having an alternate firing mode) and powerups. Alien Arena has fast, smooth gameplay, & players can play online against one another or against the bots. Please post all support issues in the forums for the game.

Post news Report article RSS Feed Alien Arena 2010(v7.45) to be released soon!

It is expected that version 7.45 of Alien Arena will be released in the next couple of weeks, with a host of updates.

Posted by Irritant_new on Jul 16th, 2010

What was expected to be a quick patch type release wound up being much, much more, so we delayed a couple of months so that all of these new features could be implemented and tested. Version 7.45 not only makes some nice changes visually, but the performance improvements are very significant. In some cases performance was increased over 100%, on the average, framerates of the game on highest settings improved around 30-50%. This will be discussed and explained further in this news post.

The first major improvement was the implementation of skeletal models using the new Inter Quake Model format. We initially saw about a 40-50% increase in rendering speed over the old MD2 format models. Again, more on this later.

New skeletal model format. Slashbot, IQM version,

Here above, we have two models rendered using the IQM format. One thing that is readily apparent is that the IQM models have more accurate bumpmapping and vertex positioning. For a more dramatic comparison, view the difference between the old MD2 and the new IQM formats below!

IQM vs MD2

Here you can see exactly what I was discussing. Believe it or not, this is the same exact model exported from Blender. The MD2 on the right has horrendous vertex deformation, and the bumpmapping is not nearly as accurate. Initially, tests on highest settings rendered the MD2 at around 240 fps in a square room(using NV9800GT) while the IQM topped out at 320 fps! When switching to simple planar stencil shadows, the difference was even more apparent, with the MD2 at 255 fps, and the IQM at 377!

These weren't the only advantages of switching to the skeletal model format. Another was the ability to actually bend the player at the waist, rather than the old method of rotating the entire model to account for player pitch. Below, you can see how an IQM is able to achieve this.

Skeletal model demonstration.

This is a pretty nice improvement over simply rotating the model, or even worse, just rotating the weapon as some engines do.

The other major visual improvement was the implementation of soft shadows for both dynamic and world lighting. The CRX engine uses a combination of shadowmapping and blurred stencil volumes to achieve this effect. We also fixed some inaccuracies from some old, hacky code that somehow had gotten overlooked in the past.

Dynamic lighting demo. Soft dynamic shadowmaps.

In the first image, you can see both the soft shadow casted by the overhead lighting, as well as the soft shadowap a little further to the left that is casted by the dynamic. In the second image, you can see soft shadowmaps casted by the stairs, which are map geometry. In the CRX engine, all objects will cast shadows(unless flagged not to do so).

We also improved some issues with self shadowing. In the case of a item that has light coming from behind, and you have a light rim with a shadow casting towards the viewer, the self shadowing would make the model almost black. We were able to do some compensation here(and the soft shadowing also helped, so that would no longer occur, as shown below.

Purgatory Soft shadows.

Lastly, another improvement is the real time specular lighting which now is not only faster, but alot more accurate. This real time lighting is a fallback for what will eventually be replaced by deluxemapping in all future map builds. What this means is, if you run an older map, as long as it has the proper textures, you will still get nice specular lighting on surfaces such as this.

Oblivion, and lighting.

Far more people will be able to run the game on the highest settings, and have a vastly more rich, and immersive world in which to frag on. Most of these performance gains and visual improvements are only seen on the higher graphic settings, but for those who run on lower settings, there were still some nice little gains here and there as well, not to mention the better looking player models, lighting, and animation. After implementing the IQM format, we were able to apply some new found knowledge to the MD2 rendering, and wound up making them run equally as fast as the IQM! The most striking example was in the test map, lighttest, with 4 MD2 player models and a weapon. In version 7.40(our last release), the tested fps was 79(on highest settings). After some optimizations with the compiler and other areas, we had gotten it to 96. After revamping the MD2 code, the fps jumped to 173, which was more than doubled the 7.40 release! If anyone has doubts, we do have screenshots showing all of this in our forums at

There were only some minor changes to gameplay in this release. At this stage, after seven years of development, we feel we have a stable, and balanced game. This doesn't mean we won't make changes in the future, as we are always open to new ideas, but it does mean that our focus is now on improving the overall client experience. You can always expect new maps, models and other content to be updated, but this release the focus was more on performance and visual quality. While some may not care for the gameplay or style of the artwork, the developers and community are very pleased with it, and the good news on that front is, there is always the ability to make a game mod. We are still working on the game scripting language that will make this very easy for anyone to create mods without having to recompile game binaries.

We are expecting to release this game in the next couple of weeks. There are still some items we are hoping to include, which may be talked about in another news post. We are also working on implementing the ODE physics engine, and ragdolls, but this will not be included as of yet. Another item that won't be included, but is getting closer to working, is the use of AutoTools for making cross platform compiling and installation vastly easier. After seven years of development, Alien Arena has never had a period of stagnation, and the core developers are more committed than ever to improving this game in every way possible.

Post comment Comments
SimonDenton Jul 16 2010 says:

Good stuff!

+1 vote     reply to comment
MadMonkey119 Jul 16 2010 says:

Nice, cant wait to try this!

+1 vote     reply to comment
Irritant_new Author
Irritant_new Jul 17 2010 says:

Looking like two weeks till release, max :) Knocking out alot of the remaining issues...crunch time.

+1 vote   reply to comment
SpookyShadow Jul 17 2010 says:

I play this game for 4 years now, and it's still getting updates!
Looks awesome!

+1 vote     reply to comment
Newbez Jul 17 2010 says:

i can't really see that much visual difference (if not none at all), however, i really look forward to the performance increase :-)

+1 vote     reply to comment
Irritant_new Author
Irritant_new Jul 17 2010 replied:

Did you not see the picture of the IQM model side by side with the MD2? The visual difference is very obvious.

+1 vote   reply to comment
Newbez Jul 18 2010 replied:

could you point some differences out please?

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Irritant_new Author
Irritant_new Jul 18 2010 replied:

Well, for starters, just look at the difference in the facial area. The MD2 model on the right, the vertexes are badly distorted and deformed. Also, look at the way the skin reflects the light. The IQM has more accurate normals and tangents, and is decidedly "cleaner". Also look at the picture in which the model is bent over. MD2 cannot bend in such a manner, the entire model has to be rotated. Screenshots don't always also show all the differences. In our latest SVN version, there is a map called "iqmtest", which has an MD2 and an IQM model side by side. You can see how much smoother the IQM animates, and how bad the vertex swim is in the MD2.

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Newbez Jul 18 2010 replied:

:) thanks, you have opened my eyes, srsly, im chinese

+1 vote     reply to comment
Six_Ways Jul 18 2010 replied:

I'm sure as you say the difference becomes more obvious in motion, but those pics really do look almost identical... the problem is that they're from different angles with different light directions, so you can't see whether the normals are more accurate and you can't see whether the facial area is distorted. I suspect you know exactly what you're looking for, but many of us can't tell the difference! But the benefits of skeletal animation are obvious.

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Irritant_new Author
Irritant_new Jul 18 2010 replied:

Click on "view original", and the picture will be large enough that the distortion is *very* apparent. Honestly I am a little flabbergasted that some cannot see the differences. It seems quite striking in my eye. I'm going to upload a video that will hopefully show more of this comparison.

+1 vote   reply to comment
Six_Ways Jul 20 2010 replied:

Re: the video - NOW it's obvious! Huge improvement.

+1 vote     reply to comment
xXMaNiAcXx Jul 17 2010 says:

Wow! Increased performance and new player models, I'm waiting for the download ^^

+1 vote     reply to comment
Ghost_face Jul 18 2010 says:

Awesome Job Irritant you are really a prime example of free standalone games, support and consistent development in this scene.

Just one question. Are there any benefits in using IQM over SKM ? Also how about having the animations stored seperate from the model and shared over multiple models ? While both is possible with skm the latter only really works if you keep the skeleton exactly the same and untouched (not even scaling is allowed which doesn't make it too useful for sharing the animation file over multiple playermodels).

Anyway keep up the great work dude !

+1 vote     reply to comment
Irritant_new Author
Irritant_new Jul 18 2010 says:

Yes, I believe you can indeed store the animations in a separate file and use them on multiple models. We didn't do so in our case just because sharing skeletons wasn't easy due to our player models being a little varied in form.

I'm not too familiar with SKM, but the main benefits I believe the IQM offers are that it stores alot more information in the model itself, like the tangents, normals and binormals, triangle neighbors, etc. Here is a site that really goes into all of it

+1 vote   reply to comment
LORDDEREX Jul 18 2010 says:

One word for this:

+1 vote     reply to comment
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Alien Arena
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Released Aug 2004
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