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Convert ObjModelParser sample parser to ES6 class #8993

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Merged
mvaligursky merged 1 commit into from
Jun 30, 2026
Merged

Convert ObjModelParser sample parser to ES6 class #8993

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86 changes: 43 additions & 43 deletions scripts/parsers/obj-model.js
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Original file line number Diff line number Diff line change
Expand Up @@ -3,48 +3,49 @@
// To use, first register the parser:
//
// // add parser to model resource handler
// var objParser = new pc.ObjModelParser(this.app.graphicsDevice);
// const objParser = new ObjModelParser(this.app.graphicsDevice);
// this.app.loader.getHandler("model").addParser(objParser, function (url) {
// return (pc.path.getExtension(url) === '.obj');
// });
//
// Then load obj as a model asset:
//
// var asset = new pc.Asset("MyObj", "model", {
// const asset = new pc.Asset("MyObj", "model", {
// url: "model.obj"
// });
// this.app.assets.add(asset);
// this.app.assets.load(asset);
function ObjModelParser(device) {
this._device = device;
this._defaultMaterial = new pc.StandardMaterial();
}

Object.assign(ObjModelParser.prototype, {
// First draft obj parser
// probably doesn't handle a lot of the obj spec
// Known issues:
// - can't handle meshes larger than 65535 verts
// - assigns default material to all meshes
// - doesn't created indexed geometry
parse: function (input, callback) {
// First draft obj parser
// probably doesn't handle a lot of the obj spec
// Known issues:
// - can't handle meshes larger than 65535 verts
// - assigns default material to all meshes
// - doesn't created indexed geometry
// eslint-disable-next-line no-unused-vars -- exposed as a global for external use (see usage comment above)
class ObjModelParser {
constructor(device) {
this._device = device;
this._defaultMaterial = new pc.StandardMaterial();
}

parse(input, callback) {
// expanded vert, uv and normal values from face indices
var parsed = {
const parsed = {
default: {
verts: [],
normals: [],
uvs: [],
indices: []
}
};
var group = 'default'; // current group
var lines = input.split('\n');
var verts = [], normals = [], uvs = [];
var i;
let group = 'default'; // current group
const lines = input.split('\n');
const verts = [], normals = [], uvs = [];

for (i = 0; i < lines.length; i++) {
var line = lines[i].trim();
var parts = line.split(/\s+/);
for (let i = 0; i < lines.length; i++) {
const line = lines[i].trim();
const parts = line.split(/\s+/);

if (line[0] === 'v') {
if (parts[0] === 'v') {
Expand All @@ -65,11 +66,10 @@ Object.assign(ObjModelParser.prototype, {
};
}
} else if (line[0] === 'f') {
var p, r;
if (parts.length === 4) {
// triangles
for (p = 1; p < parts.length; p++) {
r = this._parseIndices(parts[p]);
for (let p = 1; p < parts.length; p++) {
const r = this._parseIndices(parts[p]);
parsed[group].verts.push(verts[r[0] * 3], verts[r[0] * 3 + 1], verts[r[0] * 3 + 2]); // expand uvs from indices
if (r[1] * 2 < uvs.length) {
parsed[group].uvs.push(uvs[r[1] * 2], uvs[r[1] * 2 + 1]);
Expand All @@ -81,10 +81,10 @@ Object.assign(ObjModelParser.prototype, {

} else if (parts.length === 5) {
// quads
var order = [1, 2, 3, 3, 4, 1]; // split quad into to triangles;
for (var o = 0; o < order.length; o++) {
p = order[o];
r = this._parseIndices(parts[p]);
const order = [1, 2, 3, 3, 4, 1]; // split quad into to triangles;
for (let o = 0; o < order.length; o++) {
const p = order[o];
const r = this._parseIndices(parts[p]);
parsed[group].verts.push(verts[r[0] * 3], verts[r[0] * 3 + 1], verts[r[0] * 3 + 2]); // expand uvs from indices
if (r[1] * 2 < uvs.length) {
parsed[group].uvs.push(uvs[r[1] * 2], uvs[r[1] * 2 + 1]);
Expand All @@ -99,18 +99,18 @@ Object.assign(ObjModelParser.prototype, {
}
}

var model = new pc.Model();
var groupNames = Object.keys(parsed);
var root = new pc.GraphNode();
const model = new pc.Model();
const groupNames = Object.keys(parsed);
const root = new pc.GraphNode();
// create a new mesh instance for each "group"
for (i = 0; i < groupNames.length; i++) {
var currentGroup = parsed[groupNames[i]];
for (let i = 0; i < groupNames.length; i++) {
const currentGroup = parsed[groupNames[i]];
if (!currentGroup.verts.length) continue;
if (currentGroup.verts.length > 65535) {
console.warn('Warning: mesh with more than 65535 vertices');
}

var geom = new pc.Geometry();
const geom = new pc.Geometry();
geom.positions = currentGroup.verts;
if (currentGroup.normals.length > 0) {
geom.normals = currentGroup.normals;
Expand All @@ -119,25 +119,25 @@ Object.assign(ObjModelParser.prototype, {
geom.uvs = currentGroup.uvs;
}

var mesh = pc.Mesh.fromGeometry(this._device, geom);
const mesh = pc.Mesh.fromGeometry(this._device, geom);

var mi = new pc.MeshInstance(mesh, this._defaultMaterial, new pc.GraphNode());
const mi = new pc.MeshInstance(mesh, this._defaultMaterial, new pc.GraphNode());
model.meshInstances.push(mi);
root.addChild(mi.node);
}
model.graph = root;
model.getGraph().syncHierarchy();
callback(null, model);
},
}

_parseIndices: function (str) {
var result = [];
var indices = str.split('/');
for (var i = 0; i < 3; i++) {
_parseIndices(str) {
const result = [];
const indices = str.split('/');
for (let i = 0; i < 3; i++) {
if (indices[i]) {
result[i] = parseInt(indices[i], 10) - 1; // convert to 0-indexed
}
}
return result;
}
});
}