STL vs. OBJ vs. GLB vs. OpenSCAD: Choosing the Right 3D File Format

Does the File Format Really Matter?

You've just generated an amazing 3D model from your photo. Now it's time to download—but wait, which format? STL, OBJ, GLB, or OpenSCAD?

Short answer: yes, the format matters. A lot. Pick the wrong one and your 3D printer won't know what to do with it, or your game engine will choke on an oversized mesh. Each format was designed for a specific purpose, and understanding those differences saves headaches later. Let's break it down.

STL (Stereolithography): The King of 3D Printing

If your goal is 3D printing, STL is almost always your answer. It's the simplest and most universal format for this purpose.

• What it stores: Only the surface geometry of the object—a collection of interconnected triangles (a "mesh").
• What it doesn't store: Color, texture, material, or lighting information.
• Pros: Simple, lightweight, and supported by every single 3D slicer software (like Cura, PrusaSlicer, etc.).
• Cons: Useless for anything requiring color or visual appearance, like a game asset or AR object.

OBJ (Object File): The Versatile Veteran

OBJ has been around since the 1980s, and there's a reason it stuck around. Pretty much every 3D program on the planet can read it—Blender, Maya, Unity, Unreal, you name it.

• What it stores: Geometry (the mesh), UV mapping coordinates (how textures wrap around the model), and material information.
• How it works: The material and texture information is often stored in a separate companion file with a .mtl (Material Template Library) extension, which must be kept with the .obj file.
• Pros: Widely supported, good for transferring models between different 3D software.
• Cons: Managing multiple files (OBJ, MTL, and texture images) can be cumbersome.

GLB / glTF: The Modern Standard for Web and AR

Think of GLB as the "JPEG of 3D." One file. Everything included. No hunting for missing texture files or broken material links. It was built for the modern web—fast to load, compact, and ready for AR/VR out of the box.

• What it stores: Everything in one file! Geometry, materials, textures, and even animations. The 'B' in GLB stands for binary, meaning all this data is packed into a single, efficient file. (glTF is the JSON-based version, but GLB is more common).
• Pros: All-in-one file is easy to share and use. Loads fast on web and mobile. Meta (Facebook) uses it for 3D posts, and most AR frameworks expect it.
• Cons: While some slicers are starting to support it, it's not as universally accepted for 3D printing as STL.

OpenSCAD (.scad): The Programmer's Choice

Here's where things get interesting. STL, OBJ, and GLB are all mesh formats—they store the final shape as a bunch of triangles. OpenSCAD? It's source code. Like, actual code you can read and edit.

• What it stores: The actual instructions for creating the 3D model. Variables, functions, boolean operations, transformations—it's like getting the recipe instead of just the cake.
• What makes it special: You can modify parameters, adjust dimensions, and regenerate the mesh. Full programmatic control over your geometry.
• Pros: Full control, parametric designs, learn how the model was made, perfect for customization and iteration.
• Cons: Requires OpenSCAD software to render, steeper learning curve than mesh viewers.

3DMyPhoto is one of the few photo-to-3D tools that generates OpenSCAD source code. Most converters give you a mesh and call it done. With a .scad file, you can tweak the size, adjust the depth, combine models, or completely rework the design. It's the difference between getting a cake and getting the recipe.

Quick Comparison Table

?? Related Articles

• OpenSCAD Tutorial: From Photo to Customizable 3D Model
• Photo to OpenSCAD: Generate Parametric 3D Models
• OpenSCAD Cheat Sheet: Essential Commands for 3D Modeling
• Image to STL Converter: Complete Guide
• Photo to 3D Print: Step-by-Step Workflow