twgl.js/examples/3d-texture-volume.html
Gregg Tavares 0f6f7060d7 lint
2017-10-25 22:25:24 +09:00

376 lines
11 KiB
HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf8">
<!--
@license twgl.js Copyright (c) 2015, Gregg Tavares All Rights Reserved.
Available via the MIT license.
see: http://github.com/greggman/twgl.js for details
-->
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<meta property="og:title" content="TWGL.js - 3d-texture volume" />
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<meta property="og:image" content="http://twgljs.org/examples/screenshots/3d-texture.png" />
<meta property="og:description" content="TWGL.js - 3d-texture volume" />
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<link href="/resources/images/twgljs-icon.png" rel="shortcut icon" type="image/png">
<title>twgl.js - 3d textures</title>
<style>
body {
margin: 0;
font-family: monospace;
color: white;
}
canvas {
width: 100vw;
height: 100vh;
}
a {
color: lightblue;
}
#b {
position: absolute;
top: 10px;
right: 10px;
width: 20%;
padding: 1em;
text-align: center;
z-index: 2;
background: rgba(0, 0, 0, 0.8);
}
.controls {
text-align: right;
}
.controls div {
display: flex;
width: 100%;
justify-content: space-between;
}
.controls input {
flex: 1 1 auto;
}
.controls label {
width: 10em;
flex: 0 0 auto;
padding-right: 0.5em;
}
</style>
</head>
<body>
<canvas id="c"></canvas>
<div id="b">
<div><a href="http://twgljs.org">twgl.js</a> - 3d-texture volume</div>
<hr/>
<div class="controls">
<div>
<label for="filter">LINEAR</label>
<input type="checkbox" id="filter" /></div>
<div>
<label for="alphaThreshold">Alpha Threshold</label>
<input type="range" min="0" max="100" id="alphaThreshold"/>
</div>
<div>
<label for="zoom">zoom</label>
<input type="range" min="0" max="100" id="zoom"/>
</div>
</div>
</div>
</body>
<script src="../dist/4.x/twgl-full.min.js"></script>>
<script src="../3rdparty/chroma.min.js"></script>
<script>
"use strict";
function main() {
const m4 = twgl.m4;
twgl.setDefaults({attribPrefix: "a_"});
const gl = twgl.getContext(document.getElementById("c"));
console.log("using: " + gl.getParameter(gl.VERSION)); // eslint-disable-line
if (!twgl.isWebGL2(gl)) {
alert("Sorry, this example requires WebGL 2.0"); // eslint-disable-line
return;
}
const size = 128;
const sizeMinus1 = size - 1;
const half = size / 2;
const texture = twgl.createTexture(gl, {
target: gl.TEXTURE_3D,
width: size,
height: size,
depth: size,
wrap: gl.CLAMP_TO_EDGE,
minMag: gl.NEAREST,
});
const maxHistory = 300;
const history = [];
let historyNdx = 0;
const ctxs = [];
function drawCircleLow(ctx, color, x, y, z, radius) {
ctx.fillStyle = color;
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2, false);
ctx.fill();
gl.bindTexture(gl.TEXTURE_3D, texture);
gl.texSubImage3D(gl.TEXTURE_3D, 0, 0, 0, z, ctx.canvas.width, ctx.canvas.height, 1, gl.RGBA, gl.UNSIGNED_BYTE, ctx.canvas);
}
function drawCircle(z, color, x, y, radius) {
const old = history[historyNdx];
if (old) {
const ctx = ctxs[old.z];
ctx.globalCompositeOperation = "destination-out";
drawCircleLow(ctx, "rgba(0,0,0,1)", old.x, old.y, old.z, old.radius + 1);
ctx.globalCompositeOperation = "source-over";
}
{
const ctx = ctxs[z];
drawCircleLow(ctx, color, x, y, z, radius);
}
history[historyNdx] = {
x: x,
y: y,
z: z,
radius: radius,
};
historyNdx = (historyNdx + 1) % maxHistory;
}
for (let y = 0; y < size; ++y) {
const v = y / (sizeMinus1);
const ctx = document.createElement("canvas").getContext("2d");
ctx.canvas.width = size;
ctx.canvas.height = size;
ctxs.push(ctx);
drawCircle(y, chroma.hsv(v * 360, 1, 0.5).css(), half, half, Math.abs(Math.sin(v * Math.PI * 2)) * half);
}
const vs = `
#version 300 es
in vec4 a_position;
in vec3 a_texcoord;
in vec3 a_normal;
out vec3 v_texcoord;
out vec3 v_normal;
out vec3 v_surfaceToLight;
out vec3 v_surfaceToView;
uniform mat4 u_worldViewProjection;
uniform mat4 u_world;
uniform mat4 u_viewInverse;
uniform vec3 u_lightWorldPos;
void main() {
v_texcoord = a_texcoord;
v_normal = (u_world * vec4(a_normal, 0)).xyz;
v_surfaceToLight = u_lightWorldPos - (u_world * a_position).xyz;
v_surfaceToView = (u_viewInverse[3] - (u_world * a_position)).xyz;
gl_Position = u_worldViewProjection * a_position;
}
`;
const fs = `
#version 300 es
precision mediump float;
precision mediump sampler3D;
in vec3 v_texcoord;
in vec3 v_normal;
in vec3 v_surfaceToLight;
in vec3 v_surfaceToView;
uniform sampler3D u_volume;
uniform vec3 u_lightDir;
uniform float u_shininess;
uniform float u_specularFactor;
uniform float u_alphaThreshold;
out vec4 outColor;
vec4 lit(float l ,float h, float m) {
return vec4(1.0,
mix(0.5, 1., l * .5 + .5),
(l > 0.0) ? pow(max(0.0, h), m) : 0.0,
1.0);
}
void main() {
vec4 color = texture(u_volume, v_texcoord);
if (color.a < u_alphaThreshold) {
discard;
}
vec3 a_normal = normalize(v_normal);
vec3 surfaceToLight = normalize(v_surfaceToLight);
vec3 surfaceToView = normalize(v_surfaceToView);
vec3 halfVector = normalize(surfaceToLight + surfaceToView);
vec4 litR = lit(dot(a_normal, surfaceToLight),
dot(a_normal, halfVector), u_shininess);
outColor = vec4((
(color * litR.y + vec4(1) * litR.z)).rgb,
color.a);
}
`;
// generate 3d planes
const positions = [];
const texcoords = [];
const normals = [];
function addPoint(mapping, p, t, n) {
positions.push(p[mapping[0]], p[mapping[1]], p[mapping[2]]);
texcoords.push(t[mapping[0]], t[mapping[1]], t[mapping[2]]);
normals.push(n[mapping[0]], n[mapping[1]], n[mapping[2]]);
}
for (let y = 0; y <= size; ++y) {
const w0 = (y + 0) / size;
const w1 = (y + 1) / size;
const u0 = 0;
const u1 = 1;
const v0 = 0;
const v1 = 1;
const u0b = 0;
const u1b = 1;
const v0b = 0;
const v1b = 1;
const w0b = (y + 0.01) / size;
const w1b = (y + 0.99) / size;
[[0, 1, 2], [1, 2, 0], [2, 0, 1]].forEach(mapping => {
addPoint(mapping, [u0 - 0.5, w0 - 0.5, v0 - 0.5], [u0b, w0b, v0b], [0, -1, 0]);
addPoint(mapping, [u1 - 0.5, w0 - 0.5, v0 - 0.5], [u1b, w0b, v0b], [0, -1, 0]);
addPoint(mapping, [u0 - 0.5, w0 - 0.5, v1 - 0.5], [u0b, w0b, v1b], [0, -1, 0]);
addPoint(mapping, [u0 - 0.5, w0 - 0.5, v1 - 0.5], [u0b, w0b, v1b], [0, -1, 0]);
addPoint(mapping, [u1 - 0.5, w0 - 0.5, v0 - 0.5], [u1b, w0b, v0b], [0, -1, 0]);
addPoint(mapping, [u1 - 0.5, w0 - 0.5, v1 - 0.5], [u1b, w0b, v1b], [0, -1, 0]);
addPoint(mapping, [u0 - 0.5, w1 - 0.5, v0 - 0.5], [u0b, w1b, v0b], [0, 1, 0]);
addPoint(mapping, [u0 - 0.5, w1 - 0.5, v1 - 0.5], [u0b, w1b, v1b], [0, 1, 0]);
addPoint(mapping, [u1 - 0.5, w1 - 0.5, v0 - 0.5], [u1b, w1b, v0b], [0, 1, 0]);
addPoint(mapping, [u0 - 0.5, w1 - 0.5, v1 - 0.5], [u0b, w1b, v1b], [0, 1, 0]);
addPoint(mapping, [u1 - 0.5, w1 - 0.5, v1 - 0.5], [u1b, w1b, v1b], [0, 1, 0]);
addPoint(mapping, [u1 - 0.5, w1 - 0.5, v0 - 0.5], [u1b, w1b, v0b], [0, 1, 0]);
});
}
const programInfo = twgl.createProgramInfo(gl, [vs, fs]);
const bufferInfo = twgl.createBufferInfoFromArrays(gl, {
position: positions,
normal: normals,
texcoord: { numComponents: 3, data: texcoords, },
});
const uniforms = {
u_volume: texture,
u_worldViewProjection: m4.identity(),
u_lightWorldPos: [0.3, 1.3, -2],
u_shininess: 200,
u_alphaThreshold: 0.9,
};
const ae = document.querySelector("#alphaThreshold");
ae.value = uniforms.u_alphaThreshold * 100;
ae.addEventListener('input', e => {
uniforms.u_alphaThreshold = e.target.value / 100;
});
let zoom = 0;
const ze = document.querySelector("#zoom");
ze.value = zoom * 100;
ze.addEventListener('input', e => {
zoom = e.target.value / 100;
});
document.querySelector("#filter").addEventListener('change', e => {
const mode = e.target.checked ? gl.LINEAR : gl.NEAREST;
gl.bindTexture(gl.TEXTURE_3D, texture);
gl.texParameteri(gl.TEXTURE_3D, gl.TEXTURE_MAG_FILTER, mode);
gl.texParameteri(gl.TEXTURE_3D, gl.TEXTURE_MIN_FILTER, mode);
});
let frameCount = 0;
function render(time) {
time *= 0.001;
frameCount++;
const zp = frameCount % (size * 2);
const z = (zp >= size) ? (size * 2 - zp - 1) : zp;
const zv = z / (size - 1);
const r = Math.abs(Math.sin(time) + Math.cos(time * 0.731)) * half * .5 * Math.sin(zv * Math.PI);
drawCircle(z, chroma.hsv(time * 30 % 360, 0.75 + Math.sin(time) * .25, 0.5).css(),
half + Math.sin(time * 0.515) * (half - r), half + Math.sin(time * 0.413) * (half - r),
r);
twgl.resizeCanvasToDisplaySize(gl.canvas);
gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
gl.enable(gl.DEPTH_TEST);
gl.enable(gl.CULL_FACE);
const fov = 45 * Math.PI / 180;
const aspect = gl.canvas.clientWidth / gl.canvas.clientHeight;
const zNear = 0.01;
const zFar = 10;
const projection = m4.perspective(fov, aspect, zNear, zFar);
const ctime = 0; //time * 0.1;
const cr = 1.2 - zoom * .7;
const eye = [Math.sin(ctime) * cr, 1 - zoom * .9, Math.cos(ctime) * cr];
const target = [0, 0, 0];
const up = [0, 1, 0];
const camera = m4.lookAt(eye, target, up);
const view = m4.inverse(camera);
const viewProjection = m4.multiply(projection, view);
const world = m4.rotationY(time * 0.1);
uniforms.u_worldViewProjection = m4.multiply(viewProjection, world);
uniforms.u_world = world;
uniforms.u_viewInverse = camera;
gl.useProgram(programInfo.program);
twgl.setBuffersAndAttributes(gl, programInfo, bufferInfo);
twgl.setUniforms(programInfo, uniforms);
twgl.drawBufferInfo(gl, bufferInfo);
requestAnimationFrame(render);
}
requestAnimationFrame(render);
}
main();
</script>
</html>