Fast & Gorgeous Erosion Filter Explained

More info and links in the companion blog post here: https://blog.runevision.com/2026/03/fast-and-gorgeous-erosion-filter.html Shadertoy with animated parameters: https://www.shadertoy.com/view/wXcfWn Shadertoy with mouse-painting of terrain: https://www.shadertoy.com/view/sf23W1 Josh's video about two other techniques: https://www.youtube.com/watch?v=gsJHzBTPG0Y More info on what I've been up to here: https://blog.runevision.com Find me on social media: https://bsky.app/profile/runevision.bsky.social https://mastodon.gamedev.place/@runevision Join my Discord server: https://discord.gg/yGN7bDQ Background music: "Black Swan" by Quincas Moreira "Gently, Onwards" by ELPHNT "June" by Bobby Richards "A Mystic Experience" by Unicorn Heads "In the Atmosphere" by Bad Snacks "After All" by Geographer "Traversing" by Godmode "Decimate" by Jeremy Blake "Alone" by Emmit Fenn "Knowpe" by Noir Et Blanc Vie "Arp Bounce" by Geographer "Final Girl" by Jeremy Blake Chapters: 00:00 Introduction 03:03 Chapter I: Discovery 03:22 the origin 05:22 the basic idea 06:59 generating stripes 09:50 preserving peaks 12:41 lacking usability 14:05 Part II: Refinement 14:16 quick basics of analytical derivatives 16:04 fixes and improvements 19:48 the ugly secret 22:15 Part III: Evolution 22:22 fading revisited 26:15 scope creep 27:11 three techniques for crispness 27:38 stacked fading 29:20 normalized gullies 31:11 straight gullies 33:25 final touches