OBJ files: Understanding their uses and applications in 3D modelling.

What are OBJ files?

Wavefront Technologies created the OBJ file, which is officially called “Wavefront OBJ.” OBJ files are a standardised type of file used to store 3D geometry data. They act as a blueprint that 3D software uses to recreate 3D structures with ease.

OBJ files make it possible to store every vertex, face and texture of a design. While they can hold a lot of data, OBJ files are popular because of their simplicity and readability. OBJ files are plain text, which means humans can read them. You can open an OBJ in any text editor and see a structured list of all attributes — without any specialised software.

While OBJ files are great at describing 3D models, they need to come with Material Template Library (MTL) files to define properties such as:

• Colour
• Reflectivity
• Texture maps

In other words, the OBJ conveys the form of a model, while the MTL describes the aesthetics.

Uses of OBJ files: Diverse applications.

Gaming and virtual environments.

Video games and virtual reality (VR) applications need intricate 3D environments, objects and characters to create immersive experiences. OBJ files contain the 3D models designers need to import models into game engines and VR platforms. They include detailed geometry of all assets, ensuring every contour and texture comes across correctly.

Video games and VR also rely on efficient rendering for a good user experience. OBJ files load quickly, which reduces latency and gives end-users a smoother experience.

Animation and film industry.

OBJ files store geometric data about characters, props and scenes for animation and film. Without this data, it just wouldn’t be possible for studios like Pixar to create stories in 3D.

Film production requires multiple teams working on different software platforms, so OBJ is popular for animation. It’s a highly compatible file format that makes cross-team collaboration possible at scale.

Architectural visualisation.

Architects use OBJ files to transmit 3D renderings of buildings, interiors and landscapes. These files include both general structure and small details, which architects use to ideate internally and present realistic models to clients.

Accurate scale and detail are a must for architecture. OBJ files ensure scale, proportion and aesthetics align perfectly for the most accurate depictions possible.

3D printing and prototyping.

Manufacturers use 3D modelling and printing to quickly iterate products without the need for pricey prototypes. Designers build 3D models and save them as OBJ files, which they then convert into physical objects with 3D printers.

Designers use slicing software to break the model into layers for printing. Since OBJ files are compatible with various slicing tools, they’re a popular standard for 3D printing.

OBJ files in 3D modelling.

Creating 3D models with OBJ format.

3D artists and modellers use OBJ files as a common export format. Once they finalise a model in the software of their choice, they export all geometric data (vertexes, faces and texture co-ordinates) to OBJ.

OBJ files are popular for 3D models because they store information on UV mapping and texture co-ordinates. This set-up makes it possible to accurately project 2D images onto 3D models, which preserves the designer’s original vision.

Challenges and considerations.

While OBJ files are helpful for 3D modelling, they do have some challenges, including:

• File size. OBJs are large text-based files that take time to load. To optimise OBJ files, look into decimation tools and file compression.
• Compatibility. OBJ files are widely supported, but not all software interprets them the same way. You might see minor discrepancies when importing an OBJ across different platforms.
• Lack of animation data. OBJ files store geometry data, not rigging data. You may need to use other file formats to create animated models.

Software supporting OBJ files.

3D modelling software.

Several types of 3D modelling software support OBJ, including:

• Adobe Substance 3D
• Blender
• Maya
• 3ds Max

There are both free and paid types of software available and all are user-friendly.

Rendering and animation software.

Porting OBJ files into your rendering software will also make smoother transitions between modelling, animation and rendering. OBJ files act as a conduit for 3D data in rendering and animation software, including:

• Adobe After Effects
• KeyShot
• Cinema 4D

All software should preserve material properties during import so you don’t lose your work.

Conversion tools.

Certain game engines and niche 3D tools might not support OBJ files. Several tools can convert OBJ files into other formats, if needed, including:

• MeshLab
• Spin 3D Mesh Converter

Your journey to hyper-realistic 3D starts with Adobe Substance.

OBJ files are versatile. They bridge different use cases and software platforms from gaming to architecture and animation to 3D printing. Explore the world of 3D modelling — dive deeper into how you can use OBJ files to design limitless 3D experiences.