idwAlgo = function(gens, nb) {
let sw = 0; // sum of all weights
let sn = 0; // sum of all weighted heights
const { x, y } = this.thread;
for (let k = 0; k < nb; k++) {
const [gx, gy] = gens[k];
const [dx, dy] = [x - gx, y - gy];
const dist2 = dx * dx + dy * dy;
sn += k / dist2; // k/nb = influence of generator k
sw += nb / dist2;
}
return sn / sw;
}
cropAlgo = function(array2D, range) {
const { x, y } = this.thread;
const [min, max] = range;
const h = array2D[y][x];
return Math.min(max, Math.max(min, h));
}
computeHeightmap = {
const idwKernel = gpu.createKernel(idwAlgo, { output });
const cropKernel = gpu.createKernel(cropAlgo, { output });
const combine = function(gens, nb, range) {
return cropKernel(idwKernel(gens, nb), range);
};
return gpu.combineKernels(idwKernel, cropKernel, combine);
}
viewof height = {
const heightmap = computeHeightmap(generators, generators.length, crop);
const canvas = (render(heightmap), render.canvas);
return Object.assign(canvas, { value: heightmap });
}
height
shade
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
