Shadertoy

A gold mine of really good fragment shaders.

• https://shadertoyunofficial.wordpress.com/ - lots of cool stuff

• Fractal tree by EvilRyu

• Nimitz (stormoid)
• Shane
• Paulo Falcao
• Kali
• flockaroo
• Evvvvil
• Flopine
• Nusan
• BigWings aka The Art of Code
• knighty - many mathy things!

• Shadertoy mysterious bugs
• ANGLE can ruin many things. See this, for example. But I’m not sure if disabling ANGLE is a good idea.
• This guy has a lot of examples of precision errors.
• Don’t ask for the angle of a null vector. => atan(y,x+1e-15) ( source). But for coordinates it should be fine, as gl_FragCoord is always fractional.
• Complex expressions including redefinition of variables ( e.g., x = (x=y)*x ) may not be evaluate in the same order on some systems (typically, after translation to HLSL by Windows Angle; API drivers can also have problems), or can even be bugged (O += x -O on some old systems). (OpenGL is wrongly evaluating first all the subdefinitions while here Angle is right.) For wide compatibility, avoid reusing the same variable redefinition within a single expression – which span includes comma-separated expressions.
• there are different bugs in OpenGL… ;-/ ( e.g. on very big arrays ) ( source)

Always define your variables!

• Python program to render Shadertoys
• How to adapt iterative shaders to the power of the computer
• Set shader as a website background

• Raymarching and SDFs
• Techniques in Shadertoy and shaders