Threedee Tales From Urban Bohemia

An introduction to 3D graphics on the web using WebGL.

2. 3D is hard
3. We’re building a videogame
4. We’re building a videogame
8. (You are being a smartass)
10. WHAT?
11. WebGL is A JavaScript API to render graphics accessing directly the GPU
12. WebGL is not An API for 3D graphics
13. WebGL is not An OpenGL Wrapper
14. angle angle OpenGL ES 2.0 to DirectX 9 translation
15. angle angle OpenGL ES 2.0 to DirectX 9 translation
16. WHERE?
18. DIV
19. CANVAS DIV
20. WebGL context CANVAS “webgl” .getContext(“webgl”) WebGL context the
21. WebGL context WebGL context(s) a b a.getContext(“webg b.getContext(“webg
22. WHEN?
23. DRAW DRAW DRAW DRAW DRAW DRAW DRAW DRAW Not when you want to
24. When the browser tells you to.
25. When the browser tells you to. requestAnimationFrame
26. BRO WHAT ABOUT DOUBLE BUFFERING
28. Tearing
29. Buffer A Buffer B
30. Buffer A Buffer B
31. Buffer A Buffer B
32. JavaScript doesn’t execute while the DOM is being rendered!
33. JavaScript doesn’t execute while the DOM is being rendered!
34. HOW?
35. Introducing... Jimmy the Vertex
36. I’m not looking forward to this...
37. (x, y, z)
38. +x +y +z RIGHT HAND REPRESENT
42. Local Space
43. World Space
44. Camera Space
45. Camera Space
46. Screen Space
47. xx xy xz Yx Yy Yz Zx Zy Zz { } World Space Local Space Model Matrix
48. xx xy xz Yx Yy Yz Zx Zy Zz { } Camera Space World Space View Matrix
49. xx xy xz Yx Yy Yz Zx Zy Zz { } Screen Space Camera Space Projection Matrix
50. We could do the matrix operations in JavaScript
51. We could do the matrix operations in JavaScript BUT WE DON’T
52. SHADER is a program that runs on the GPU. SHADER a
53. (THAT WAS EASY)
54. N N It begins with an...
55. OT JAVASCRIPT N N It begins with an...
56. GLSL GLSL OpenGL Shader Language
57. precision highp float; varying vec2 t; varying vec2 pos; uniform float time; uniform vec2 mouse; uniform int mouseLeft; uniform sampler2D tex0; void main() { float v1 = (sin(t.s+time) + 1.0) / 2.0; float v2 = (cos(t.t+time) + 1.0) / 2.0; float d = distance(mouse, pos); vec2 tt = vec2(t.s+sin(time/10.0), t.t+cos(time/10.0)); vec4 c1 = texture2D(tex0, tt) * 1.1; float avg = (c1.r+c1.g+c1.b)/3.0; float r = c1.r+v1*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float g = c1.g+v2*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float b = c1.g - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); gl_FragColor = vec4(r, g, b, 1.0); }
58. precision highp float; varying vec2 t; varying vec2 pos; uniform float time; uniform vec2 mouse; uniform int mouseLeft; uniform sampler2D tex0; void main() { float v1 = (sin(t.s+time) + 1.0) / 2.0; float v2 = (cos(t.t+time) + 1.0) / 2.0; float d = distance(mouse, pos); vec2 tt = vec2(t.s+sin(time/10.0), t.t+cos(time/10.0)); vec4 c1 = texture2D(tex0, tt) * 1.1; float avg = (c1.r+c1.g+c1.b)/3.0; float r = c1.r+v1*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float g = c1.g+v2*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float b = c1.g - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); gl_FragColor = vec4(r, g, b, 1.0); } WELL THIS KINDA LOOKS LIKE JAVASCRIPT WELL THIS KINDA LOOKS LIKE JAVASCRIPT
59. precision highp float; varying vec2 t; varying vec2 pos; uniform float time; uniform vec2 mouse; uniform int mouseLeft; uniform sampler2D tex0; void main() { float v1 = (sin(t.s+time) + 1.0) / 2.0; float v2 = (cos(t.t+time) + 1.0) / 2.0; float d = distance(mouse, pos); vec2 tt = vec2(t.s+sin(time/10.0), t.t+cos(time/10.0)); vec4 c1 = texture2D(tex0, tt) * 1.1; float avg = (c1.r+c1.g+c1.b)/3.0; float r = c1.r+v1*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float g = c1.g+v2*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float b = c1.g - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); gl_FragColor = vec4(r, g, b, 1.0); }
60. precision highp float; varying vec2 t; varying vec2 pos; uniform float time; uniform vec2 mouse; uniform int mouseLeft; uniform sampler2D tex0; void main() { float v1 = (sin(t.s+time) + 1.0) / 2.0; float v2 = (cos(t.t+time) + 1.0) / 2.0; float d = distance(mouse, pos); vec2 tt = vec2(t.s+sin(time/10.0), t.t+cos(time/10.0)); vec4 c1 = texture2D(tex0, tt) * 1.1; float avg = (c1.r+c1.g+c1.b)/3.0; float r = c1.r+v1*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float g = c1.g+v2*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float b = c1.g - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); gl_FragColor = vec4(r, g, b, 1.0); } “
61. precision highp float; varying vec2 t; varying vec2 pos; uniform float time; uniform vec2 mouse; uniform int mouseLeft; uniform sampler2D tex0; void main() { float v1 = (sin(t.s+time) + 1.0) / 2.0; float v2 = (cos(t.t+time) + 1.0) / 2.0; float d = distance(mouse, pos); vec2 tt = vec2(t.s+sin(time/10.0), t.t+cos(time/10.0)); vec4 c1 = texture2D(tex0, tt) * 1.1; float avg = (c1.r+c1.g+c1.b)/3.0; float r = c1.r+v1*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float g = c1.g+v2*pow(avg,4.0) - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); float b = c1.g - pow(d,pow(avg,2.0) +float(mouseLeft)*avg); gl_FragColor = vec4(r, g, b, 1.0); } <script id="fragment-shader" type="x-shader/x-fragment"> </script>
62. document.getElementById document.getElementById
63. GLSL GLSL GLSL compile compile compile link
64. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Perspective Matrix Model View Matrix
65. attribute vec3 aVertexPosition; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); }
66. attribute vec3 aVertexPosition; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); } Output
67. attribute vec3 aVertexPosition; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); } Output Uniforms
68. attribute vec3 aVertexPosition; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); } Output Uniforms Attribute
71. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Passing Uniforms var ptr = gl.getUniformLocation(shaderProgram, "uPMatrix") gl.uniformMatrix4fv( ptr, false, new Float32Array(vertexes));
73. -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, Here come the vertices
74. -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, Here come the vertices
75. -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, Here come the vertices
76. -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, Here come the vertices
77. -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, Here come the vertices
78. cubeVertices = gl.createBuffer(); gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertices); gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW); gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertices); gl.vertexAttribPointer(vertexPositionAttribute, 3, gl.FLOAT, false, 0, 0); 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 Passing Vertices
79. cubeVertices = gl.createBuffer(); gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertices); gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW); gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertices); gl.vertexAttribPointer(vertexPositionAttribute, 3, gl.FLOAT, false, 0, 0); 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 Passing Vertices
80. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Uniforms gl_Position 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 [aVertexPosition] drawArrays*
81. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Uniforms gl_Position 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 [aVertexPosition] drawArrays*
82. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Uniforms gl_Position 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 [aVertexPosition] drawArrays*
83. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Uniforms gl_Position 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 [aVertexPosition] drawArrays*
84. xx xy xz Yx Yy Yz Zx Zy Zz { } xx xy xz Yx Yy Yz Zx Zy Zz { } Uniforms gl_Position 0,1,0 1,0,0 0,1,1 1,0,1 1,1,1 [aVertexPosition] drawArrays*
85. Rasterization
88. Fragments
89. Fragment Shader varying lowp vec4 vColor; void main(void) { gl_FragColor = vColor; }
90. Fragment Shader varying lowp vec4 vColor; void main(void) { gl_FragColor = vColor; } Output
91. Fragment Shader varying lowp vec4 vColor; void main(void) { gl_FragColor = vColor; } Output Variant
92. Variants Vertex Shader Fragment Shader
95. Color
96. Color Texture
97. Color Texture Lighting
98. Color Texture Lighting Specularity
99. Color Texture Lighting Specularity Normal Mapping
100. Color Texture Lighting Specularity Normal Mapping ...
101. Clear Canvas Load Perspective M atrixes Load O bject M atrixes Render O bject
103. Three.js https://github.com/mrdoob/three.js A.K.A. use
104. 3D is hard
105. 3D is hard hard to understand
106. 3D is hard hard to understand hard to learn
107. Hard to get right
108. But we need to try
110. twitter.com/vmg github.com/vmg
111. With demos from: http://wagerfield.github.io/flat-surface-shader/ http://lab.aerotwist.com/webgl/surface/ http://www.mrdoob.com/lab/javascript/beachballs/ http://plumegraph.org/