converts proprietary matterport dam models to obj

dam2obj.js

const protobuf = require("protobufjs");
const fs = require("fs");
const fetch = require("node-fetch");

async function go(id) {
    console.log(`Downloading list of files for ${id}...`);
    let files;
    try {
        files = await (await fetch(`https://my.matterport.com/api/player/models/${id}/files?type=1&format=json`)).json();
    } catch (err) {
        console.log(err);
        console.log("Failed to download list of files.");
        return;
    }

    if (files.code) {
        console.log(`Failed to download list of files: ${files.message}`);
        return;
    }

    let modelID = "";

    for (const key in files) {
        if (key.includes("_50k.dam")) modelID = key;
    }

    console.log("Downloading model...");
    let rawModel;
    try {
        rawModel = await (await fetch(`${files[modelID]}`)).buffer();
    } catch (err) {
        console.log("Failed to download model.");
    }
    
    const proto = (await protobuf.load(__dirname + "/dam.proto")).lookupType("DAMFile");
    const model = proto.decode(rawModel);

    console.log("Converting to MDL...");

    if (!fs.existsSync("./out")) fs.mkdirSync("./out");

    let objOut = "mtllib model.mtl\n";
    let mtlOut = "";
    let faceOffset = 1;
    model.chunk.forEach(c => {
        const xyz = c.vertices.xyz;
        const uv = c.vertices.uv;
        const faces = c.faces.faces;

        if (!mtlOut.includes(c.materialName)) {
            mtlOut += `newmtl ${c.materialName}\n`;
            mtlOut += `map_Kd ${c.materialName}\n`;
            fetch(files[`${modelID.replace(".dam", "")}_texture_jpg_high/${c.materialName}`]).then(r => {
                r.buffer().then(data => {
                    fs.writeFileSync(`./out/${c.materialName}`, data);
                });
            });
        }

        for (let i = 0; i < xyz.length; i+=3) {
            objOut += `v ${xyz[i]} ${xyz[i + 1]} ${xyz[i + 2]}\n`;
        }

        for (let i = 0; i < uv.length; i+=2) {
            objOut += `vt ${uv[i]} ${uv[i + 1]}\n`;
        }

        objOut += `usemtl ${c.materialName}\n`;

        for (let i = 0; i < faces.length; i+=3) {
            objOut += `f ${faces[i] + faceOffset}/${faces[i] + faceOffset} ${faces[i + 1] + faceOffset}/${faces[i + 1] + faceOffset} ${faces[i + 2] + faceOffset}/${faces[i + 2] + faceOffset}\n`;
        }

        faceOffset += xyz.length / 3;
    });
    fs.writeFileSync("./out/model.mtl", mtlOut);
    fs.writeFileSync("./out/model.obj", objOut);
    console.log("Done!");
}


go(process.argv[process.argv.length - 1]);