• Interactive Poisson Blending on GPU
    Interactive Poisson Blending on GPU
  • 404 Not Found In Two Triangles
    404 Not Found In Two Triangles
  • Simplest and Fastest GLSL Edge Detection using Fwidth
    Simplest and Fastest GLSL Edge Detection using Fwidth

Category: Tutorial

Unified Gnomonic and Stereographic Projections

Gnomonic projection, or rectilinear projection, together with stereographic projection, are two most commonly used projection in rendering 360 degree videos, or other VR applications. Recently, I found the inverse converting function from screen coordinates to the two projections can be unified within a single function. It’s not really surprising since both projection uses spherical lens,…


Equirectangular, Gnomonic Projections, and Cubemaps

Background According to MathWorld, the gnomonic projection is a nonconformal map projection obtained by projecting points P_1 (or P_2) on the surface of sphere from a sphere’s center O to point P in a plane that is tangent to a point S (Coxeter 1969, p. 93). In a gnomonic projection, great circles are mapped to…


SIGGRAPH Asia 2014 Course Materials from iq/rgba

iñigo quilez kindly provides his SIGGRAPH Asia 2014 Course Materials of ShaderToy with me via email. Thank you iq! Thinking implicit: 2D, non polygonal shapes Coordinates and color gradients (That link is depracated, so I personally recommend this link instead) Shapping Texture Mapping Animation Reactivity More Media Yet More Media Thinking implicit: 3D Raymarching Modeling (primitives and…


Tutorial and Resources for Three.js

Three.js is one of a number of free WebGL libraries. First released in April 2010, it has become pretty popular, and includes a huge number of demos. I wanted to know more about its origins, so interviewed its creator, Ricardo Cabello, aka mr.doob, who lives in Spain. Interestingly, I am also largely motivated by Demoscenes when I was…


Tutorial of Ray Casting, Ray Tracing and Ray Marching

Introduction As GPU power is becoming significantly better than CPU, ray casting / tracing and ray marching is widely used in 4k intros and demoscenes to create 3D (interactive) graphics. – Thanks to all the references listed in the end, I learnt so much about and I would like to share with the knowledge to my friends. This tutorial…


Quick Tutorial on Refereces Management using Mendeley / Endnote / Word / ShareLaTeX

Managing a large library of references for researchers can be hard work. I usually use Mendeley + ShareLaTeX for writing papers. Both tools are free and easy to collaborate with co-authors. Mendeley + ShareLaTeX First, please install Mendeley from its official website. Here is an official YouTube video introducing Mendeley: There is also a quick…


[Tutorial] Introduction and Installation of WebVR

Today I tried a new technology called WebVR. According to WebVR.info: WebVR is an experimental Javascript API that provides access to Virtual Reality devices, such as the Oculus Rift or Google Cardboard, in your browser. It tries to provide a uniform interface for all sorts of VR headsets such as Oculus Rift DK2, Google Cardboard…