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  • License MIT

Explore infinite 3d worlds from the comfort of your terminal

Package Exports

  • ascii-raytracer

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (ascii-raytracer) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

ascii-raytracer

Explore infinite 3d worlds from the comfort of your terminal!

Simple utility takes a signed distance function and lets you explore it with realtime raytracing (marching spheres) or alternatively by using a user-provided raytracing function. No GPU needed!

blob world

Why?

For retro fun, to experiment with distance functions / 3d algorithms / ray-tracing / data-stuctures / optimization without dealing with browser, GPU, ect.

Table of Contents

Installation

npm i ascii-raytracer

Controls

  • A/S/W/D - move camera

  • Arrow Keys - rotate camera

  • Q/E - rise/fall

  • R/F - change field of view

  • C/X - change camera mode

  • V - Toggle anti-aliasing (runs 4x slower)

  • Hold shift to move/rotate faster

Simple Example - Blob World

//here just a distance function - raytracing is done with marching spheres

//distance function format:
//funtion(x,y,z){return signedDistanceToScene;}

//see src of dfBlobWorld for more details

var art = require('ascii-raytracer');

var config = {
    distanceFunction: art.distanceFunctions.dfBlobWorld
}

art.runScene(config);

blob world

With Custom Raytracer - Maze

//here we additionally include a custom raytracing function [much faster than naive marching spheres]

//raytrace function format:
// function(ray) { 
//     var o = ray.point; //{x,y,z} origin of ray
//     var v = ray.vector; //{x,y,z} direction of ray
//     return distance;
// }

//example with a maze build from axis aligned bounding blocks

var art = require('ascii-raytracer');

var config = {
    distanceFunction: art.distanceFunctions.dfMaze,
    raytraceFunction: art.distanceFunctions.dfMazeTrace, //raytracer uses RTree 
    resolution: 64,
    aspectRatio: 1.0
}

art.runScene(config);

maze

Polygon Mesh with Bounding Volume Hierarchy

//example with polygon mesh, 5000 triangles
//raytracer uses bounding volume hierarchy 

var art = require('ascii-raytracer');

var config = {
    distanceFunction: art.distanceFunctions.dfSkull,
    raytraceFunction: art.distanceFunctions.dfSkullTrace,
    resolution: 64,
    aspectRatio: 1.0
}

art.runScene(config);

skull

UV Texture Mapping

specify config.uvFunction and config.textureFunction to render a 2D texture onto the scene.

  • uvFunction takes (x,y,z) as input and returns [u,v] texture coordinates in range 0...1
  • textureFunction takes (u,v) as inputs and returns [r,g,b] color data in range 0...1

in this example we load a PNG file with the readimage module and then specify textureFunction to pull color values from the image, and uvFunction for tiling the image.

the scene is the same maze from the earlier example. 

var art = require('ascii-raytracer');
var fs = require("fs")
var readimage = require("readimage")
var filedata = fs.readFileSync("./cat.png")

readimage(filedata, function (err, image) {
    var w = image.width;
    var h = image.height;
    var d = image.frames[0].data;

    var myTextureFunction = function(u,v){ //pull colors from texture data
        var xc = Math.floor(u*w);
        var yc = Math.floor(v*h);
        var o = (yc*h+xc)*4;
        return [d[o]/255, d[o+1]/255, d[o+2]/255] //return [r,g,b] in range 0...1
    }

    var myUvFunction = function(x,y,z){ //tile texture across XZ plane
        return [Math.abs(x/1.0)%1.0, Math.abs(z/1.0)%1.0]; //return u,v coords
    }

    var config = {
        distanceFunction: art.distanceFunctions.dfMaze,
        raytraceFunction: art.distanceFunctions.dfMazeTrace,
        uvFunction: myUvFunction,
        textureFunction: myTextureFunction,
        resolution: 64,
        aspectRatio: 1.0
    }

    art.runScene(config);
})

texture cat

3D Texture Mapping

Specify textureFunction3d instead of textureFunction if you want to define surface colors directly from a 3D function.

In this example we apply 3D perlin noise [from the blob world example] as the surface texture for our maze.

Because the blob world distance function varies over time, the texture is animated!

var art = require('ascii-raytracer');

var my3dTextureFunction = function(x,y,z){
    var d = Math.abs(art.distanceFunctions.dfBlobWorld(x*15,y*15,z*15))/2.0; //using 3d perlin noise to define color
    return [d,d,d] //return [r,g,b]
}

var config = {
    distanceFunction: art.distanceFunctions.dfMaze,
    raytraceFunction: art.distanceFunctions.dfMazeTrace,
    textureFunction3d: my3dTextureFunction,
    resolution: 64,
    aspectRatio: 1.0
}

art.runScene(config);

maze with perlin noise