Behind the Behind the Bullet

Behind the Bullet: An exclusive behind the scenes look at the Killzone 2 Bullet commercial; that is the synopsis for the previously codenamed Killzone: 4D tech demo. Behind the Behind the Bullet: An exclusive summary and opinion for the behind the scenes look at the Killzone 2 Bullet commercial; is the synopsis for what you are about to read.

Well, this marvelous little demo popped up on the US PSN yesterday and I’ve watched it through close to 30 times now. Why? Isn’t it obvious? I’m a geek. I love technology waffle of all sorts, especially when it’s based on a game as graphically mind blowing as Killzone 2.

The demo basically is the TV spot, literally. Without wanting to do things the easy way, it’s not just a video.What those Dutch-geniuses have provided is an actual real time render.  This means that not only is your PS3 actually rendering it there and then, but it’s interactive too. Cue techgasm. Whilst the interactivity is fairly limited – you can rotate and tilt slightly around the path of the bullet – it is the debug mode that intrigues me the most. With four seperate commentaries explaining different sections of the demo, there’s more tech talk than our future American penthouse will hold.


Toggling the debug mode shows the current debug mode in for the left half, and the finished version in the right. The debug modes are as follows:

  • Pixel Orientation (see above) – This shows the base models of the levels and characters, with the colouring depicting the orientation of each pixel, which is used for normal mapping.
  • Shininess – Used to scale the reflectiveness and specular properties of the pixel.
  • No Post – Shows the render without lens effects, colorization, advanced lighting or particles.
  • Lighting – Shows, well, the lighting.
  • Depth – A cleanly defined grey scale image shows the pixel distance from the camera – with white being close, black being far away and greys filling the gaps in between – which is ultimately used for depth of field.

My personal favourite was the ‘No Post’ debug. Seeing the difference that all of the flashy effects makes to a final render is truly remarkable. Make no mistake though, the quality of the graphics and textures before post is quite something, but it’s all the extras which help make it such a graphical powerhouse. As a modeller myself, I loved to see the detail in some of the character models using the ‘Pixel Orientation’ mode.

Usually, the PS3’s memory would be split between a variety of different tasks, such as graphics, sound and gameplay. However, with this being so scripted, no memory was used for gameplay mechanics, freeing up memory for super hi-res models and texture maps to help put us right in the sight of the gun. Guerrilla Games were able to increase the resolution of the eye so much, it uses the same amount of texture space as the rest of the character. It’s ridiculous isn’t it? Equally, the bullets resolution is ramped up, utilizing the same amount of polygons as the gun it came from. With everything setup at max-res, some shots were pumping out a massive 100million polygons. In order to help optimize for at least 30fps, models, lights and effects that could not be seen by the user were removed. Enough textures had to be emitted to help improve the performance without losing the detail that is so crucial to the heavy hitting first-person shooter; which would have been made increasingly difficult having had to scale up the motion blur to suit more effectively to the slow-motion shots.


GG also hinted that some techniques that were used in the demo will be used in future games (Killzone 3 anyone?) High-frequency detailed mapping was used to add sand to concrete, coarse to skin and simulate visible threads. This technique was used in the game itself, although on the level exclusively, not the characters; this however has since changed. The Killzone 2 engine doesn’t have support for real reflections, so their fast working coders have been working on true planar reflections, to simulate reflections on water; but was unfortunately not optimised in time for this project.

Killzone 2 is, in my opinion, the best looking game to date. It’s as fun to play now as it was on release date and equally as impressive. Huge congratulations are in order for the guys and gals at the Amsterdam-based studio; as well as great thanks for such a techy treat.