Since the debut of Half-Life 2 almost 20 years ago, it has noticeably aged. It is still interesting to play the classic shooter, its plot laid the foundation for subsequent generations, but most importantly - the game’s characters had unparalleled eyes.
The game developer, Joe Wintergreen, in his Dev Scoops blog, talked about how the eye textures in Half-Life 2 are the best in the business.
“At some point, I tried to make my characters’ eyes beautiful, and the gold standard for that was (and possibly still is) Half-Life 2,” Wintergreen writes. He explains that the characters’ eyes are not “rotating meshes with many small details, but rather more or less flat planes with shaders that make them look like spheres.”
To properly explain how Valve managed to achieve this eye effect over the years, Wintergreen turned to the developer who worked specifically on these eyes, Ken Birdwell. Apparently, three main textures were used for the eyes. One of them was used for “simulating self-shadowing from the eyelids.” Another one was used for the iris. And the third one was used to simulate the convexity of the cornea.
After Birdwell and his team obtained the three main textures, they only needed to properly position the iris and cornea to “create the effect of visual contact.” According to Birdwell, “all the necessary data for this can be found in any eye anatomy textbook.” Aspiring eye makers should not “worry about eye rotation,” because our eyes “slightly rotate as you look around, because of how the muscles are attached to them, but it is imperceptible to humans.”
“I think an example of this code still exists in the SDK, maybe in hlmv?” Birdwell said. “I know that in the end, it was all replaced with a fancy shader that does all this in one pass, but that didn’t happen in the HL2 version, and the code might still be there.”
<Digging into the code is already the realm of Half-Life fans. Remember that Half-Life 2 was released in November 2004 on PC, and then as part of the Orange Box package, the game appeared on PS3 and Xbox 360.
Link from www.playground.ru