column-mesh/example/main.js

generate a 3d mesh of a greek column

var column = require('../')
var mesh = column({
  radius: 2,
  height: 20
})

var regl = require('regl')()
var normals = require('angle-normals')
var camera = require('regl-camera')(regl, {
  center: [0,0,0],
  eye: [0,0,1],
  distance: 30
})
var mat4 = require('gl-mat4')
var rmat = []

var draw = regl({
  frag: `
    precision mediump float;
    varying vec3 vnormal;
    void main () {
      gl_FragColor = vec4(abs(vnormal), 1.0);
    }
  `,
  vert: `
    precision mediump float;
    uniform mat4 projection, view, model;
    attribute vec3 position, normal;
    varying vec3 vnormal;
    void main () {
      vnormal = normal;
      gl_Position = projection * view * model * vec4(position, 1.0);
    }
  `,
  attributes: {
    position: mesh.positions,
    normal: normals(mesh.cells, mesh.positions)
  },
  uniforms: {
    model: (context) => {
      var theta = context.time*0.25
      return mat4.rotateY(rmat, mat4.identity(rmat), theta)
    }
  },
  elements: mesh.cells
})
regl.frame(() => {
  regl.clear({ color: [0,0,0,1] })
  camera(() => { draw() })
})