Citadel design evolution
The Citadel went through various designs during Half-Life 2’s development. They can be described thanks to the various pieces of concept art, WC map pack maps, and the models, textures, and environment maps found in the playable Half-Life 2 leak files.
- 1 Oldest known versions
- 2 2001 versions
- 3 2001-2002 versions
- 4 E3 2002 version
- 5 August 2002 - July 2003 versions
- 6 September 2002 - March 2003 version
- 7 Retail version
- 8 References
Oldest known versions
- Viktor Antonov, Dhabih Eng and Eric Kirchmer made several pieces of concept art depicting various iterations of the Citadel, including organic versions. Whether these versions made it past the concept art stage is unknown.
- The vignette Old Friends from the uncorrected proof of Half-Life 2: Raising the Bar features a Citadel fitted with an "eye" that shoots plasma.
Inside the Citadel (Antonov).
Train stopped at a platform, with the Citadel in the distance (Eng).
The entrance to the Citadel's inner wall, originally found in maps such as
VanceHQ, with in the background a Citadel similar to the one featured in the previous image (Unknown artist, probably Eng).
Gordon arriving at the Citadel's lower entrance, with concrete shapes similar to those featured in the map
The Citadel among American skyscrapers (Kirchmer).
This version is featured in several revisions of the map
c17_04, from revision 21 to 28, made from March to June 2001. The previous versions of
c17_04 do not feature a Citadel, the next versions have this Citadel replaced by the next iteration. The Citadel is entirely brown and apparently not detailed, while a closer look shows it is detailed, featuring a round lump (seen in the posters), windows and other precise shapes. This version was to be separated from the rest of City 17 by a tall concrete barrier known as the "inner wall" or "inner gates", as mentioned by Alyx in the Half-Life 2 leak sound files. Another map,
proto_c17inner, from March 2001, also features this Citadel (the front and rear and reversed, compared to
c17_04) and provides a closer look at the area behind the inner wall, featuring concrete building-like structures and deep holes in the ground emitting greenish light. The aforementioned structures appear to be forcibly built into a previously existing city block.
There is only one known map of the interior of this Citadel, existing in two revisions:
proto_core001 (January 2001) and
proto_core002 (February 2001), showing an early iteration of the Citadel Core that will eventually appear in Half-Life 2: Episode One.
proto_c17citadel_skybox, from April 2001, features a less detailed spire, which appears grey-colored, not brown, and seems to be based on the concept art for the Citadel's lower entrance. Here the spire is shown to be rising out of a deep shaft in the ground, surrounded by the same brown concrete building-like structures.
The shaft under the Citadel in
proto_c17citadel_, with the Borealis’ plimsoll line reused.
Viktor Antonov made concept art for this version, while Aaron Barber and Randy Lundeen designed the maps of the outside and inside, respectively. In the WC map pack, this is the version with the most maps, featuring numerous instances of both the exteriors and interiors.
This Citadel, covered in metal, is made of different cylinders stacked on top of each other, with other shapes stuck around them, and topped with an antenna-like shape. The metal textures used in the various maps are
j, which are missing from the leak files,
metalwall065a being the only one left and not used for the Citadel. This version comes in two known variations: One with a tapered shape, the other with a thicker appearance. Incidentally, the City 17 logo is similar to a cross-section of this Citadel.
Inside, all floors, walls and ceilings are entirely covered in tiles of various colors and sizes. Metal and glass pipes with organic forms can also be found all around, as well as dangling chains, some with speakers are their end, and mechanisms such as pistons (similar to those seen in the Air Exchange) and rotating valves. The maps also feature a prison area with Vortigaunts in the cells. Concept art for the Depot's prison is based on such maps.
This Citadel's exterior is featured in maps such as:
c17_04: From revision 29 to 41 (August 2001 to February 2002).
proto_citadel_002: In a real-life size (April 2001).
proto_citadel_001is missing from the map pack but its envmap is still present in the playable leak's texture files.
proto_citadel_skybox: Featuring the nighttime satellite image of Manhattan also used in the final game, and an optional visgroup of human and Combine buildings such as towers (similar to the Air Exchange's industrial tower) connected to it at its base (October 2001). The revision
proto_citadel_skybox3includes a concrete wall similar to the previous version's inner wall surrounding its base (Same month).
This Citadel's interior is featured in maps such as:
proto_citadel_interiorand its variations (May 2001).
proto_citadel_tankroom(August 2001). It is reused in
demo_citadel01(October 2001) and
demo_citadelpipes(February 2002). The envmap texture file for
proto_citadel_tankroomalso includes two color variants.
proto_citadel_advisors: Features a long shaft. Though its names suggests a relation to the Combine Advisor, no models of the Synth are present. This may be an early instance of the Advisor shaft featured at the start of Episode One (October 2001).
proto_citadel_cellblock(July 2001). It is reused in
proto_citadel_garbage(October 2001). Also exists as
demo_camshaft: A demo map not set in the Citadel but reusing the same assets (February 2002). Older version of
proto_citadel_interior 1 to 3
proto_citadel_cellblock / demo_citadel01
proto_citadel_garbage / demo_citadel02
This round and blueish version (and the first known model,
citadelfar.mdl) was first seen in the Half-Life 2 E3 2002 Trailer. Another feature appearing in the trailer is a single cable connecting the Citadel to one of the Combine Factories buildings (In
e3_terminal from May 2002). It appears in
e3_terminal and its variants (April to May 2002),
e3_strider and its variants (April to May 2002) and
canals_01_11 (June 2002). The model appears green-tinted due to having its own greenish envmap.
August 2002 - July 2003 versions
The near final version, designed by Jeff Ballinger, Viktor Antonov, and Danika Wright, was first created with depots at its feet like the other version made around the same time. This version can be found in
d1_under0102a, with added small Citadel parts as the model
CombineCitadel.mdl (April 2003).
In the other maps it is found, it has no depots, and is a brush or a model (
Combine_citadel.mdl). Revisions 12 and 14 of
canals_01 (Brush, June and July 2002),
prefab_combine2 (Brush, June 2002, as
canals_01 with added Citadel parts as the model
CombineCitadel.mdl, with a larger unused Citadel found in the map void),
proto_innerwall (Brush, July 2002, as
canals_01 with added Citadel parts), and in the screenshot of a more recent version of
e3_terminal, and as a model in the map d1_under0102 (June to July 2003),
d1_under0102b and its variants (Model, May to June 2003),
proto_combine_underground5 (January 2003, same skybox as
proto_c17map (March 2003, same mix of brush and model as in
proto_c17combine (August 2002),
proto_combine_underground5 (Close to the base of the Citadel; features the Depot model at its feet, January 2003). Then a model was created; this is the one featured in the Half-Life 2 leak; it is almost identical to the next and latest version.
Concept art for the inside of the Citadel, reused in the final game as the map background menu
September 2002 - March 2003 version
This version is a cylinder flanked with buttresses that go beyond the cylinder's top. At its feet, it reuses the same depots than the near final version worked on concurrently, with just one additional smaller depot. It can be found in the map
proto_docks (September 2002),
d1_sewer51g (January 2003),
d1_sewer51i (February 2003),
d1_sewer51j (February 2003), and two versions of
d1_under0102 (February and March 2003).
The last version, a set a several models depending on context, is featured in Half-Life 2 and its Episodes. The final evolution of the August 2002 - July 2003 versions, that triangular prism is bluer and more detailed, and no longer contains Depot models at its feet.
During the course of the game, Half-Life 2 uses a total of 5 models.
At the start of the game until the failed teleportation (
d1_trainstation 01, 02, 04 and 05), the game uses the model
Combine_Citadel001b.mdl, which is an idle Citadel whose top is hidden in the clouds. Model
Combine_Citadel_animated.mdl is used next, and only once in the game, when the Citadel sets itself on full alert after Gordon has been discovered following the teleportation failure (
Its alert model with the top in the clouds,
Combine_Citadel001b_open.mdl, is used in the Canals (
d1_canals_01 to 03, and 05 to 07) and during the City 17 uprising (
d3_c17_01 to 07, and 09). The subsequent uprising maps (
d3_c17_10a to 13) use
Combine_Citadel001_open.mdl, with the top no longer hidden in the clouds.
Combine_Citadel001.mdl is used only when reaching the foot of the Citadel, with its base as brush work within the playable map itself (
Half-Life 2: Episode One
Half-Life 2: Episode Two
- Half-Life 2: Raising the Bar, page 246
- Half-Life 2: Raising the Bar, page 173
- Half-Life 2: Raising the Bar, page 243
- Into The Pixel
- WC map pack
- Half-Life 2: Episode One commentary
- Half-Life 2: Raising the Bar, page 283
- Danika Wright's resume
- Half-Life 2: Raising the Bar (uncorrected proof), page 359
- Half-Life 2: Raising the Bar, page 249
- Half-Life 2: Raising the Bar, page 250
- Half-Life 2: Raising the Bar, page 172
- Half-Life 2: Raising the Bar, page 248
- Half-Life 2: Raising the Bar (uncorrected proof), page 173
- Half-Life 2: Raising the Bar, page 201
- Half-Life 2: Raising the Bar, page 225
- Half-Life 2 leak
- Half-Life 2: Raising the Bar, page 251