The short answer
Two families of format share the word “3D” but behave nothing alike. Mesh formats (OBJ, FBX, glTF, STL, USD) describe a surface as triangles — what artists, game engines and viewers use. CAD formats (STEP, IGES, and native parts like SolidWorks or Revit) describe precise mathematical solids for engineering. A catalog that can render one family may show a grey icon for the other, which is why 3D assets break so many general-purpose libraries. Get the interchange target right — glTF for meshes, STEP for CAD — and every downstream tool cooperates.
The six formats at a glance
| Format | What it stores | Best for | Open? | Browser preview |
|---|---|---|---|---|
| OBJ (.obj) | Static geometry + basic materials (.mtl) | Handing off a single static mesh | Yes (open spec) | After conversion |
| FBX (.fbx) | Geometry, materials, rig, animation | Moving rigged/animated assets between DCC tools | No (Autodesk) | After conversion |
| glTF / GLB | Geometry, PBR materials, animation | Web, AR and viewer delivery — the interchange target | Yes (Khronos) | Native |
| USD / USDZ | Whole-scene composition & layers | Large film/sim pipelines; USDZ for Apple AR | Yes (Pixar/ASWF) | Partial / native (USDZ on Apple) |
| STL (.stl) | Raw triangle mesh, no color or units | 3D printing | Yes | After conversion |
| STEP (.stp/.step) | Precise CAD solids (B-rep), no textures | Neutral CAD interchange in engineering | Yes (ISO 10303) | After tessellation |
“After conversion/tessellation” means the format isn't drawn by a browser directly — the DAM must generate a mesh or image preview server-side. Only glTF/GLB (and USDZ on Apple hardware) render without that step.
Mesh formats: OBJ, FBX, glTF, STL, USD
OBJ is the plain text of 3D — a decades-old Wavefront format that stores vertices, faces and, via a companion .mtl file, basic materials. No rig, no animation, often no single-file guarantee (textures live beside it). It is nearly universal precisely because it is simple, which makes it a safe way to hand a static prop from one tool to another.
FBX is the workhorse of production. Owned by Autodesk, it carries everything OBJ can't — skeletons, skinning, animation takes, cameras, lights — and is the default when an asset moves between 3ds Max, Maya, Blender, Unity and Unreal. The catch is that it's proprietary and versioned: an FBX exported from a newer tool can trip an older importer, so pipelines pin a version.
glTF (JSON-based) and its binary sibling GLB are the Khronos Group's answer to “a format built for delivery, not authoring.” Often called the JPEG of 3D, glTF is compact, supports physically-based materials and animation, and — crucially for a library — is rendered natively by browsers and most modern viewers. That is why it's the interchange target we recommend keeping alongside every master file, and why 3D asset management tools lean on it for previews.
USD (Universal Scene Description), from Pixar and now the Alliance for OpenUSD, is a different animal: it composes entire scenes from layered references rather than describing one object. It's the backbone of high-end film and simulation work; USDZ is Apple's zipped, single-file variant that iPhones and iPads open as AR out of the box. STL rounds out the set as the 3D-printing format — pure watertight geometry, no color, no units, so it's export-only for most catalogs.
CAD formats: STEP, IGES and native parts
Engineering files are not meshes. A STEP file (.stp/.step, ISO 10303) stores a boundary representation — exact curves and surfaces — so a hole is a mathematically perfect cylinder, not a ring of triangles. That precision is the whole point in manufacturing, but it means a DAM can't just draw a STEP file; it has to tessellate it into a display mesh first. The same holds for older IGES (.igs) and for native parts like SolidWorks (.sldprt), Inventor (.ipt) and Revit (.rvt), which are proprietary on top of that. Keep STEP as the neutral interchange copy next to the native master, and confirm your specific extensions preview before you standardize — this is exactly the gap that separates a real engineering DAM from a generic one.
The opaque-blob trap: most tools will happily store any of these formats. Storing is not previewing. If the catalog shows a generic 3D icon instead of the actual model, nobody can find the right mesh without opening it — the single most common complaint we hear about 3D in a general DAM. Test preview, not just upload.
A format strategy that survives contact with reality
You will never get one format to do every job, so don't try. The pattern that holds up: keep originals in their authoring format as the system of record (that's where editability lives); generate a glTF/GLB derivative for preview, web and AR; and for engineering data, keep a STEP copy beside the native part as the neutral interchange. Then let a tool that understands the master-and-derivative relationship keep them in sync, so a change to the source regenerates the lightweight copies instead of leaving stale duplicates behind. The Khronos glTF standard has become the safe default derivative for exactly this reason.
FAQ
What is the difference between OBJ, FBX and glTF?
OBJ is a simple, universal format for static geometry and basic materials — no animation or rig. FBX is Autodesk's rich but proprietary format that carries geometry, materials, rigs and animation, and is the default exchange in game and film pipelines. glTF (and its binary form GLB) is the open Khronos standard built for runtime and the web: compact, PBR materials, animation, and rendered natively by browsers. Rule of thumb: OBJ to hand off a static mesh, FBX to move a rigged/animated asset between authoring tools, glTF to deliver to web, AR or a viewer.
Which 3D format is best for asset management?
Keep your originals in their authoring format (Max, Blender, Revit, SolidWorks) as the master, and standardize on glTF/GLB as the lightweight preview and interchange derivative — it is open, compact and the one format browsers and most DAMs render natively. For engineering data, keep STEP as the neutral CAD interchange alongside the native part files. A capable 3D asset management tool tracks the master-and-derivative relationship so an update to the source propagates.
Can a DAM preview STEP and other CAD files?
Only if it tessellates them. STEP, IGES and native CAD parts store precise B-rep solids, not display meshes, so a DAM must convert them to a triangle mesh to show a preview. Tools built for engineering archives (such as Daminion) generate these previews server-side; generic cloud DAMs usually fall back to a generic icon. Always confirm your exact extensions (.stp/.step, .iges/.igs, .sldprt) render before committing.
What is USD and do I need it?
USD (Universal Scene Description), created by Pixar, describes and composes whole scenes rather than single objects, and is the backbone of large film and simulation pipelines; USDZ is Apple's zipped variant for AR on iOS. You need it if you assemble complex multi-asset scenes or ship AR to Apple devices; for a shared library of individual models, glTF is the simpler, more widely supported choice.