## Shaders 

[Minions Art](https://www.patreon.com/minionsart)

[Alan Zucconi](https://www.alanzucconi.com/tutorials/)

[Vertex Shader Art](https://www.vertexshaderart.com)

[ShaderToy](https://www.shadertoy.com)

## SpriteKit shaders

[SpriteKit: Shaders & Geometry by Matt Reagan](http://sound-of-silence.com/?article=20180806)

## NPAR: Non-Photorealistic Animation and Rendering

[Non-Photorealistic Computer Graphics by Thomas Strothotte and Stefan Schlechtweg](http://a.co/d/5TGTu5L)

[A Non-Photorealistic Lighting Model For Automatic Technical Illustration](https://www.cs.utah.edu/~shirley/papers/gooch98.pdf)

[Watercolor Inspired Non-Photorealistic Rendering for Augmented Reality](https://www.cc.gatech.edu/~turk/my_papers/npr_ar_2008.pdf)

[Comprehensible Rendering of 3-D Shapes](https://www.cs.princeton.edu/courses/archive/fall00/cs597b/papers/saito90.pdf)

[Real-Time Watercolor for Animation by Thomas Luft and Oliver Deussen](https://kops.uni-konstanz.de/bitstream/handle/123456789/6323/Real_Time_Watercolor_for_Animation.pdf)

[Youtube channel for AG Deussen - Visual Computing](https://www.youtube.com/channel/UCFEzGdPhmJ_lLPGNPxZ38sg)

[Visual Computing Publications](http://graphics.uni-konstanz.de/publikationen/)

## Core Image filters

[Core Image for Swift by Simon Gladman](https://itunes.apple.com/us/book/core-image-for-swift/id1073029980?mt=13)

[Apple Filter reference](https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CoreImageFilterReference/)