To export an AI architecture model to IFC, DXF and GLB is to choose what the receiving application needs: IFC4 carries building elements with classes, quantities, hosted openings and rooms with areas, for Revit and Archicad; DXF carries drawings, a dimensioned plan, four elevations and two sections on named layers, for AutoCAD and any 2D CAD; GLB and OBJ carry geometry with named nodes and materials and nothing else, for SketchUp, Blender, 3ds Max, Unreal and web viewers. Nuit derives all of them from the same parametric script, so they agree with each other exactly, and export is free and unlimited. What is lost is different in each, and that is what this article is for.
It is the chooser. The detail of each format lives elsewhere: AI to Revit for the IFC import, What’s Inside an AI-Generated DXF for the DXF layer by layer, SketchUp + AI for the GLB. Here: which, when, and what to check.
Why the format decides what the file is
An exporter can only write what the model knows. A text-to-mesh generator knows a surface, so its export is a surface in whatever container you pick; calling it .ifc would not make it a building. Nuit’s model is a script that builds each element with its IFC class, which is what lets three formats carry three different kinds of information from one source (AI BIM Model Generator explains the classification).
The three formats sit at three levels of meaning:
| IFC4 | DXF | GLB / OBJ | |
|---|---|---|---|
| Carries | Elements with classes, quantities, relationships | Drawings on layers with dimensions and text | Geometry with names and materials |
| Knows a wall is a wall | Yes (IfcWall) | By layer (A-WALL) | By node name only |
| Knows a door is in a wall | Yes (IfcRelFillsElement) | No | No |
| Room areas | Yes (IfcSpace, NetFloorArea) | As text labels | No |
| Dimensions | As quantities | As drawn dimension chains | No |
| Materials | None in published files | None | Colours; scan maps at best |
| Storeys | One | Plan cut at chosen level | n/a |
| For | Revit, Archicad, BIM viewers | AutoCAD, any CAD | SketchUp, Blender, 3ds Max, Unreal, web |
Everything below follows from that table.
IFC4: for BIM
Choose it when the model is going into Revit or Archicad to be developed, or into a BIM viewer to be checked.
The Mirror Lake House file on the examples page, counted at build time, has 1,079 elements: 12 IfcWall, 16 IfcSlab, 2 IfcRoof, 12 IfcColumn, 205 IfcBeam, 5 IfcWindow, 7 IfcDoor, 6 IfcStair, 45 IfcRailing, 566 IfcCovering (cladding boards), 12 IfcFurniture, 5 IfcSpace with areas summing to 110.4 m², and 7 IfcBuildingElementProxy for elements the schema could not name. Twelve openings, each related to its wall (IfcRelVoidsElement) and its door or window (IfcRelFillsElement). Quantities on every element, units in metres, one IfcBuildingStorey.
In Revit the walls are walls, the doors are hosted in them, the spaces schedule with their areas and the beams are structural framing. Link IFC first; Open IFC when you want editable elements. The 216 extruded elements (walls, slabs, columns, most beams) can be developed as bodies; the 875 mesh elements (cladding, site, furniture) arrive classified and should be replaced.
Lost: families and types (every element is a generic instance), material build-ups (the published files carry none; cladding is separate IfcCovering elements), project parameters, ratings, services, and any second storey. LOD 200 geometry, LOD 100 information. Before importing, count the IfcSpace against the brief, read their areas, confirm doors have a fill relationship, and note that there is one storey.
DXF: for drawings
Choose it when the model is going to AutoCAD or to anyone who works in 2D, or when you need a plan to overlay on a survey or a planning envelope.
One DXF, seven views laid out in model space three metres apart, each with a text label: a plan cut at 1.2 m, four elevations, two sections. Overall and wall-axis dimension chains as lines and text, room outlines on A-AREA labelled with name and area on A-ANNO-TEXT, level marks on the elevations. Layers are mapped from each element’s IFC class: 24 declared with colours, of which Mirror Lake House uses 19 (A-WALL, A-FLOR, A-ROOF, A-GLAZ, A-DOOR, S-COLS, S-BEAM, S-MEMB, I-FURN, L-PLNT among them). Library assets are one closed silhouette per instance; the full-geometry alternative was a 232 MB file, the silhouetted one is 1.6 MB with 3,239 polylines. Millimetres by default.
In AutoCAD the plan lands with layers you can freeze, dimension text you can read, and elevations that agree with the plan because both are projections of one model. Copy the plan into your template and start replacing outlines with your wall types; AutoCAD + AI walks through the opening sequence.
Lost: blocks (doors are drawn geometry), hatches, paper-space layouts and a title block, associative dimensions (they do not update when you stretch a wall), opening and detail dimensions, hidden-line removal on the elevations, line weights beyond layer colour. One plan level per export, chosen in the export panel. Before importing, confirm the units and read the seven view labels and the layer list.
GLB and OBJ: for geometry
Choose GLB when the model is going to Blender, recent SketchUp, 3ds Max, Unreal, Unity, a web viewer or a rendering pipeline and you want the scene hierarchy intact; OBJ when the importer does not read glTF.
The whole scene arrives as nested groups named after the elements in the script: each wall, beam, column, opening, roof element and room volume as its own node, plus deck, railings, site (lake surface, rocks, banks) and library assets as instances, the 24 pines at about 27,000 triangles each. Materials as colours; where a scan material from the catalogue was applied in the studio, expect its colour map at best. GLB keeps all of this in one binary file; OBJ writes the same geometry with a flat hierarchy and an MTL file for basic materials.
In SketchUp set the import units to metres (a 20 m house arriving as 20 inches is the usual first mistake), merge coplanar faces, and hide the planting group while you work. In Blender the hierarchy arrives as an object tree with the same names.
Lost: every building semantic. No IFC classes, quantities, drawn dimensions, layers or room areas; a GLB knows that a node is called “Main bedroom door” and does not know it is a door. Before importing, open the file in any glTF viewer and read the node tree; if the names are there, the file is intact.
Which to send to whom
- A Revit or Archicad office developing the concept: IFC4. Send the DXF as well if they want the plan as a flat drawing for early sheets.
- An AutoCAD office doing 2D schematic design: DXF. The IFC is of little use without a BIM application.
- A visualiser or a SketchUp user: GLB, or OBJ if their importer needs it. They will remodel or dress it; the classes would be wasted on them.
- A client: none of these. The web viewer on the 3D page is how a model is shown to someone who does not have CAD; the files are for the people who do.
- Your own archive: all three, from the same checkpoint. Exports are free and unlimited, and the IFC is the one that will still say what it is in ten years.
What no export carries
The parameters. The exported file is the geometry at one checkpoint; the script with its sliders stays in Nuit, and further parametric editing happens there. Settle the concept before exporting rather than importing five versions into Revit to compare them, because an edit in the studio costs 5 to 25 credits or nothing (sliders, drag, materials) and an import costs an afternoon. AI Parametric Design Tool covers what stays editable and where.
Multiple storeys. IFC and DXF write one storey today. A two-storey concept exports as two files, one per floor.
Construction information. Nothing in any of the three formats is a construction document; the model is concept-stage geometry with correct dimensions and classes, to be developed in your own software. Generating it costs 60 to 150 credits, with an estimate first; the exports cost nothing. Plans are on the pricing page. The 3D mode is open to every account from the Images | 3D switch in the studio.
Download the three Mirror Lake House files and open each in the application it is meant for. The table above is the claim; the files are the evidence.
Frequently Asked Questions
Which format should I export an AI architecture model to?
IFC4 for Revit, Archicad and BIM viewers; DXF for AutoCAD and 2D CAD; GLB or OBJ for SketchUp, Blender, 3ds Max, Unreal and web viewers. Nuit exports all from the same model, free.
What does an IFC export from an AI model contain?
Classified elements with quantities, hosted openings, rooms with areas, a spatial hierarchy with one storey. Mirror Lake House: 1,079 elements, 5 spaces, 110.4 m². No families, types, materials or project parameters.
What does a DXF export from an AI model contain?
One file, seven views in model space (plan at 1.2 m with dimensions and room labels, four elevations, two sections) on 24 declared AIA-style layers, 19 used by Mirror Lake House. Polylines, lines and text only.
What is the difference between GLB and OBJ for architecture?
GLB keeps hierarchy, names and PBR materials in one binary file; OBJ is universal but flat, with basic materials via MTL. Neither carries classes, quantities or dimensions.
Can I export the same AI model to all three formats?
Yes, from the same script at the same checkpoint, so they agree exactly. Free and unlimited; you own the files.
What is lost when exporting an AI model?
Parameters in every format; families, types, materials and extra storeys in IFC; blocks, hatches, layouts and associative dimensions in DXF; all building semantics in GLB and OBJ.
How do I check an exported AI model before importing it?
Open it in a free viewer and read what it declares: class counts and space areas in IFC, view labels and layers in DXF, node names in GLB. The examples page prints the counts from the files at build time.
Try Nuit free — 300 credits (12 images), no card required. Open the example files in your own software first; when 3D access is enabled, export your own model in whichever format the next person needs. Start your project →