The Evolving Style of Source Games
I finally got around to purchasing the Left 4 Dead games by Valve recently! Although I haven't had the chance to play them properly yet, I have spent some time messing around with the maps on GMod and going through their developer commentaries, and I've really liked them!
I only started playing Valve games for myself for the last year or so, and I've played them a lot, as it seems they nicely scratch an itch in my brain. However, when I played Left 4 Dead 2 specifically, I thought of something I never really noticed before, and made me — quite literally — look at Source games in a different light.
(Disclaimer: I am not an expert on this topic, I am just a Valve enthusiast with some knowledge of visual design. I am just speaking from how I personally see things.)
The Source Engine launched in November 2004, with the first new games to release with it being Counter-Strike: Source and Half-Life 2 (and Half-Life 1: Source, which I am not counting since all its assets are ripped straight from the original).
Both of these games were very realistic in style, with realistic textures and lighting, even with HL2's science fiction setting. This would remain the case for the rest of the games in the HL2 franchise and Day of Defeat: Source.
Then, something interesting happened. In October 2007 The Orange Box was released, with its big title being Half-Life 2: Episode Two, but two other new games were released alongside it.
Portal 1, despite its more futuristic setting and design, still maintained a realistic style for its textures and lighting. The other title, however, changed everything.
Team Fortress 2, despite originating from a Half-Life 1 mod, went a completely different direction with its more cartoony models, simpler textures, and phong shading which makes the highlights and shadows have higher contrast.
Although Episode Two was originally the big title for The Orange Box, Team Fortress 2 probably ended up being the most influential for the studio, as it marks the turning point of most Source games deviating from full-on realism!
The next games to come from Valve were the Left 4 Dead titles, which despite returning to some form of realism, still kept some of the design decisions of TF2. Specifically the higher contrast thanks to the phong shading (which in this game added a larger sense of fear due to it being darker) and the models were slightly less polygonal. I find this most noticeable in the trailers of the games.
Left 4 Dead 2 polished the style a bit more, and I feel like its style is shared by the often forgotten Alien Swarm, with it feeling slightly more cartoony due to the less human nature of its monsters.
Portal 2, despite it being the sequel to a relatively realistic game, went a completely different direction. I've heard some people say that Portal 1 took its design from Half-Life 2, while Portal 2 took it from Team Fortress 2, and I couldn't agree more.
It took the phong shading and smoother textures from TF2, but the addition of more cartoony-feeling characters such as P-Body and Atlas, and even Wheatley to an extent, helped give it that more unified, slightly cartoony look Valve games were getting, while keeping the slightly "clinical" look of its predecessor.
The final 2 Valve games on the original Source engine broke the mold in different ways. Dota 2 is by far the most cartoony of all Valve games, but despite it featuring all the design decisions that made Team Fortress 2 so cartoony, what really made it was its character design, which was pure magical fantasy.
The penultimate game released for the engine, however, did the exact opposite. Counter-Strike: Global Offensive returned to the extremely realistic style from CS: Source, but due to the general model, texture, and lighting improvements from the eight years of the Source engine being refined, it looked even more realistic. This led to the two final games on the Source 1 engine being the least realistic and most realistic games Valve made respectively.
And that's that! I wanna reiterate that I am not an expert and I have a very basic knowledge of this topic, but it was still something I found very interesting just from my own understanding and experiences! Lots of these are amongst my favourite games of all time, and Valve is possibly my absolute favourite video game studio of all time, so it's interesting to see how the aesthetic of their games during the Source 1 era changed through time!
