[Playing With Danger plays as the camera pans to the classes outside of RED's base in 2Fort while the title of the video and the names of three developers (Jason Mitchell, Moby Francke, and Dhabih Eng) appear.]
Jason Mitchell: "In this paper, we present a set of artistic choices and real-time shading techniques which support each other to enable the unique rendering style of Team Fortress 2."
[Concept art of the Engineer, the Pyro, and the Spy are shown before their in-game models on various areas in Well.]
Jason Mitchell: "Heavily influenced by early 20th century commercial illustrations, the 3D models and shading algorithms in Team Fortress 2 work together to quickly convey geometric information using rim highlights, as well as variation in luminance and hue, so the players are able to quickly identify other players in the game and assess the possible threat."
[The Spy shoots the camera before it fades to black.]
[Cuts to static silhouettes of the nine mercenaries against a white background sliding across the screen.]
Jason Mitchell: "Through very intentional art direction, this goal was supported by designing characters with distinct silhouettes that can be easily identified even with no lighting cues. The body proportions, weapons, and silhouette lines were explicitly designed to give each character a unique silhouette.
[The silhouettes fade into their coloured versions.]
Jason Mitchell: "In the shaded interior areas of the characters, the clothing folds were designed to echo silhouette shapes in order to emphasize the silhouettes, as observed in the commercial illustrations which inspired our designs."
[Cuts to exterior shots of 2Fort.]
Jason Mitchell: "For the architectural elements of the world associated with each of the two teams, we define specific contrasting properties. While the RED team's architecture tends to use warm colours, wooden materials, and angular geometry, the BLU team's buildings are composed of cool colours, industrial materials, and orthogonal forms.
[Concept art of the areas near the 2Fort Intelligence are shown before their in-game versions.]
Jason Mitchell: "By maintaining a minimal level of visual noise in our world design, we employ an almost impressionistic approach to modelling. This philosophy was also central to our texture painting style throughout the game. The red and blue colours used to paint opposing areas of the game world are analogues to one another as guided by this reference colour swatch with muted colours dominating and small areas of saturation used to provide further visual interest.
[The colour swatch shows up on screen.]
[Parts of Well, such as floors and pipes, are shown with their texture on the right.]
Jason Mitchell: "The texture maps used on the 3D world are impressionistic and maintain a minimum level of visual noise. This is consistent with background plates found in animated films, particularly those of Hayao Miyazaki, in which broad brush strokes appear in perspective as if present in the 3D world, rather than on the 2D image plane. We apply the same approach because we feel that its inherent frame-to-frame coherence has superior perceptual properties to an image-spaced painterly approach."
[Cut to the Heavy walking outside RED's base in Well with his Minigun revved up.]
Jason Mitchell: "To shade our characters, we combine a variety of traditional and novel lighting terms."
[Heavy freezes and turns completely white with generic grey shadows.]
Jason Mitchell: "Here we see a character with a traditional clamped Lambertian diffuse term and constant ambient. You can see that the character loses definition for pixels not hit directly by the light source."
[Heavy's shadows become redder, stronger and more contrasted while its light warp texture shows up on the bottom left.]
Jason Mitchell: "We scale, bias, and warp the Lambertian term to achieve a look consistent with our illustrative influences."
[Heavy turns grey, showcasing the ambient cube.]
Jason Mitchell: "Instead of a constant ambient term, we sample from an irradiance volume in order to provide a higher quality spatially varying directional ambient term."
[Heavy turns white again to show the new shadows.]
Jason Mitchell: "Here, we show this term added to the warped per-light diffuse contributions."
[Heavy's textures return.]
Jason Mitchell: "And here, we show these diffuse terms multiplied with the albedo."
[Heavy turns completely black. Faint, yellow highlights can be seen on some parts of his body and his Minigun.]
Jason Mitchell: "We also add a number of view-dependent terms to further enhance the look of the characters. Traditional Phong highlights from up to four local lights are incorporated, where quantities such as a scalar mask, Fresnel parameters, and specular exponents can be specified by artists. We combine these Phong highlights with additional broad Phong lobes which are modulated with a harsh Fresnel falloff, causing them to appear only at grazing angles."
[The yellow highlights fade away in lieu of faint white rim lights.]
Jason Mitchell: "Finally, we add in a dedicated rim term which is derived from our irradiance volume, so that characters are always highlighted with an appropriate rim term, even if they are far away from local light sources."
[The yellow highlights fade back in.]
[Heavy returns to normal, fully lit and fully shaded. He continues walking with his Minigun revved up.]
[Cut to Heavy firing his Minigun on Dustbowl in Meet the Heavy while the Team Fortress 2 theme plays.]
Jason Mitchell: "This combination of art direction and technology choices has enabled us to create a compelling visual style while serving critical gameplay goals, such as the ability of players to readily identify each other during the fast-paced action of Team Fortress 2."
[Cut to class group photo with Team Fortress 2 logo.]
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