Runtime OBJ Importer (URP)

Wavefront .obj + .mtl importer that runs at runtime and in the Editor. Materials are created against the Universal Render Pipeline / Lit shader, so it slots straight into a URP project.

This is a fork of Dummiesman's Runtime OBJ Importer, repackaged as a Unity Package Manager (UPM) package and updated for Unity 6.x / URP.

Requirements

• Unity 2022.3 LTS or newer (verified against Unity 6.3 + URP).
• The Universal RP package installed and a URP asset assigned in Project Settings → Graphics.

Installation

Option 1 — Install via Git URL

In Unity, open Window → Package Manager, click the + button → Install package from git URL..., and paste:

https://github.com/EDivePlus/unity-runtime-obj-importer.git

Option 2 — Add to manifest.json

In Packages/manifest.json add:

{
  "dependencies": {
    "com.ediveplus.objimporter": "https://github.com/EDivePlus/unity-runtime-obj-importer.git"
  }
}

Option 3 — Local install

Clone the repo and use Package Manager → + → Install package from disk..., selecting this repo's package.json.

Player builds

The importer creates materials with Shader.Find("Universal Render Pipeline/Lit") at runtime. For a Player build to find that shader you must add it to Always Included Shaders:

1. Open Project Settings → Graphics.
2. Under Always Included Shaders, add an entry and pick Universal Render Pipeline/Lit.

The first build after this change can take a while as Unity compiles every shader variant.

Usage

using Dummiesman;

// From a file path (also loads any MTL referenced by the OBJ).
var go = new OBJLoader().Load("C:/models/teapot.obj");

// From a stream (no materials — supplies a default white material).
using (var stream = File.OpenRead("C:/models/teapot.obj"))
    go = new OBJLoader().Load(stream);

// OBJ + MTL streams.
using (var objStream = File.OpenRead("teapot.obj"))
using (var mtlStream = File.OpenRead("teapot.mtl"))
    go = new OBJLoader().Load(objStream, mtlStream);

In the Editor you also get a GameObject → Import From OBJ menu item.

Samples

Two example scripts are shipped under Samples~/RuntimeImport/. Import them via the Package Manager UI (select the package → Samples → Import):

• ObjFromFile — UI for loading an .obj from a path on disk.
• ObjFromStream — downloads an .obj over the web (UnityWebRequest) and parses it from memory.

Features

• Material file (MTL) loading with diffuse/bump/specular/emission maps.
• Runtime texture loader supporting BMP, TGA, JPG, PNG, DDS, CRN.
• Decent import speed (~750k triangles in ~10s).
• Loads triangles, quads, and ngons.
• Works in Editor and at runtime.
• Stream-based loading with overridable texture-load callback.

License

MIT — see LICENSE.md. All credit to the original author, Dummiesman.