redblobgames/1843-planet-generation

One week experiment: learn how to procedurally generate maps on a sphere. Code is messy but it runs.

This was a 9 day (2.5hr/day) experiment to learn how to procedurally generate maps on a sphere. I hadn’t worked with this type of sphere geometry before and wanted to learn.

Geometry

Writeup - Fibonacci points, Delaunay triangles, Voronoi regions

Maps

Writeup - tectonic plates, mountains, oceans, biomes, rivers, rendering

Installation

To build, run ./build.sh . Then visit embed.html . ]

1843-planet-generation's Issues

Help and brainstorm

1. I find the hills a bit boring. The kind of go up and come down at +/- same rate, and look like stars on lower regions count. Overall they look not so nice. How I could spice it up by not killing performance and load times?

2. My drawing engine is a bit limited, I can do only triangles (connect 3 verts etc). What would you advice in this situation, to draw an evaluated map (not flat veronoi)

What is make?

I dont understand how to build /run it

Info - Keep latlong with triangle data

I see the latlong is generated, converted to cartesian and then to stereographic.

How should I link and retain the triangle vertex latlong data?

I want to pair this with topojson for interaction.

Field assign function

Hi! I could not make sense of some of function you wrote, so i did my version. What it does, is, for example takes mountain 1 and assign distances on its neighbors, than for next mountain etc. When all mountains are iterated, it goes trough again, but assigns neighbor neighbors, etc., until all is assigned. In simple words it kind of radiates the fields out for the seed 1 by 1. What do you think? Seems to work, but results are different.

/* Distance from any point in seeds_r to all other points, but 
 * don't go past any point in stop_r */
function assignDistanceField(mesh, seeds_r, stop_r) {
    const randInt = makeRandInt(SEED);
    let {numRegions} = mesh;
    let r_distance = new Float32Array(numRegions);
    r_distance.fill(Infinity);
    
    let queue = [];
    for (let r of seeds_r) {
        queue.push(r);
        r_distance[r] = 0;
    }


    let r_field = [];
    var i = 0;

    while(queue.length > 0){

        if(r_field[i] === undefined){
            r_field[i] = [queue[i]];
        }

        let new_r_field = [];

        for (let n = 0; n < r_field[i].length; n++) {
            let current_r = r_field[i][n];
            let neighbor_rs = mesh.r_circulate_r([], current_r);            

            for (let neighbor_r of neighbor_rs) {
                if (!stop_r.has(neighbor_r)){
                    let new_r_distance = r_distance[current_r] + 1;

                    if (r_distance[neighbor_r] === Infinity) {
                        r_distance[neighbor_r] = new_r_distance;  
                        new_r_field.push(neighbor_r);
                    }else if(new_r_distance < r_distance[neighbor_r]){
                        r_distance[neighbor_r] = new_r_distance;
                    }
                }                
            }
        }        

        r_field[i] = new_r_field;

        if(r_field[i].length === 0){
            queue.splice(i, 1);
            r_field.splice(i, 1);
        }

        i++;

        if(i >= queue.length){ // shuffle
            i = 0;
        }
    }
    

    /*let out_r = [];
    for (let queue_out = 0; queue_out < mesh.numRegions; queue_out++) {
        let pos = queue_out + randInt(queue.length - queue_out);
        let current_r = queue[pos];
        queue[pos] = queue[queue_out];
        mesh.r_circulate_r(out_r, current_r);
        for (let neighbor_r of out_r) {
            if (r_distance[neighbor_r] === Infinity && !stop_r.has(neighbor_r)) {
                r_distance[neighbor_r] = r_distance[current_r] + 1;
                queue.push(neighbor_r);
            }
        }
    }*/

    return r_distance;
    // TODO: possible enhancement: keep track of which seed is closest
    // to this point, so that we can assign variable mountain/ocean
    // elevation to each seed instead of them always being +1/-1
}

You're amazing

This looks amazing. Haven't tried the code, but the snapshots are beautiful! Good job!