A real-time shader demo for the Game Boy Color has appeared on the internet, and it's got us in the creative mood. Just think about that for a minute though; a real-time shader on the Game Boy Color is wild, with everything happening on a CPU that is quite basic and doesn't even have a multiplication instruction.
According to Renpou.com, the shader uses a normal map that has been pre-generated, all combined with logarithmic transformation and lookup tables. The end result for those in the know is pseudo-Lambert shading and dynamic lighting in real time, on a console that I just usually use to play Pokémon Gold!
ゲームボーイカラーで「リアルタイム3Dシェーダー」を動かす驚愕のデモが登場!!
— 吉野@連邦(renpou.com) (@yoshinokentarou) February 3, 2026
乗算命令すら持たないCPU上で、事前生成した法線マップを用い、対数変換とルックアップテーブルによって疑似Lambertシェーディングと動的ライティングをリアルタイム処理で成立させているンだ!!https://t.co/UczYrQrpX0 pic.twitter.com/igyhXzEmL1
The project itself was made by Danny Spencer back in December 2025, though has recently been picked up by budding artists to play around with. In his blurb, Danny explains that the player controls an orbiting light and can spin objects. The calculations on his page are completely out of this world to me and look like an alien language, but for anyone wanting to check this project out in greater detail, you can take a look at both Danny's blog and the source code on GitHub.
You can also have a go at the shader online on Danny's blog, spinning a teapot around and playing with the shading to create your own moody look. It's all very clever, and while it won't keep you occupied as long as Dragonyhm, it will certainly push you to get out your papers and charcoal or to load up Photoshop and get drawing!
