Practical UI physics

Presented at Develop Denver 2015.

Watch the video on YouTube: https://www.youtube.com/watch?v=90oMnMFozEE
Demos on CodePen: http://codepen.io/collection/XgYvmv/
Demos on GitHub: https://github.com/desandro/practical-ui-physics

Adding physics-based motion to UI can make digital interactions feel natural, comfortable, and delightful. So why is it so hard to get right, especially on the web? While mobile device SDK's have physics-based libraries built-in, web developers are missing a straight-forward way to add physics to their sites. This talk aims to solve that. Physics is a huge subject, and physics programming is often intimidating. But for UI developers, we need only to take advantage of its core principles in a practical model. This talk will cover the fundamentals of physics programming, how to develop your own physics model in JavaScript, and how to use that model to make UI feel natural.

Transcript

1. Practical UI Physics Dave DeSandro @desandro
10. Physics
11. Practical UI Physics
12. Why Physics?
14. Mouse ! Precision — pen Might not need physics
15. Touch ! General — finger Physics feels right
16. Box2D JS
18. Practical You understand it User interface For the benefit of your users
20. Practical UI physics Change position with drag Keep moving after flick Flick movement slows Rubber band at ends
21. Physics basics
22. position velocity force friction
23. function  update()  {      velocity  *=  friction      position  +=  velocity   }   ! function  applyForce(  force  )  {      velocity  +=  force   }
24. Basics demo
25. Drag demo
26. Forces
27. function  update()  {      velocity  *=  friction      position  +=  velocity   }   ! function  applyForce(  force  )  {      velocity  +=  force   }
28. var  wind  //  particle  force   ! function  update()  {      applyForce(  wind  )      velocity  *=  friction      position  +=  velocity   }   ! function  applyForce(  force  )  {      velocity  +=  force   }
29. Wind force demo
31. position target distance  =  target  -­‐  position force  =  distance  *  strength
32. var  attractionStrength  =  0.02;   ! function  update()  {      //  attract  particle  to  target      var  distance  =  target  -­‐  positionX;      var  attraction  =  distance  *
        attractionStrength;      applyForce(  attraction  );   !    //  integrate  physics      velocity  *=  friction;      position  +=  velocity;   }
35. Attraction demo
37. Conditional demo
39. Flickity demo
40. Bonus: 
 Rubber band bounds
42. Rubber band bounds demo
43. //  calculate  resting  position   rest  =  position  +      velocity  /  (  1  -­‐  friction  )
44. function  update()  {      velocity  *=  friction      position  +=  velocity   }   ! function  applyForce(  force  )  {      velocity  +=  force   }
45. More resources Nature of Code (Ch. 1 & 2)
 natureofcode.com Coding Math
 youtube.com/user/codingmath
46. These demos codepen.io/desandro/tag/practical-ui-physics github.com/desandro/practical-ui-physics
47. Thank you! — @desandro Try Flickity