Angel Step - CAD Step / Iges / Brep Importer & Exporter for Blender

kleinARt in Import & Export


DOCUMENTATION · VERSION 3.0

AngelSTEP User Guide

Import CAD files into Blender, tune every part after the import, and export your scene back to STEP. This guide covers both editions, AngelSTEP and AngelSTEP Pro, and follows the order you work in: install, import, tune, export.

Features marked PRO are in AngelSTEP Pro only. Features marked NEW IN 3.0 are new in this version. Everything else is the same in both editions.

Blender with an imported gearbox and the AngelSTEP Live Link panel in the sidebar

1 · Install 2 · Import 3 · Tune 4 · Export

1 · Install and update

  1. In Blender open Edit › Preferences › Add-ons.
  2. Click Install from Disk and pick the zip for your system (Windows, Linux or macOS): angelstep for AngelSTEP, angelstep_pro for AngelSTEP Pro.
  3. Make sure AngelSTEP (or AngelSTEP Pro) is ticked.

Nothing else is needed: no Python packages, no runtimes, no CAD program. Blender 4.2 or newer.

Updating: remove the old version in the add-on preferences, restart Blender, then install the new zip. The native core is locked while Blender has it loaded, so the restart matters.

Upgrading to Pro: disable or remove AngelSTEP first, then install and enable AngelSTEP Pro. Only one edition can be enabled at a time. Your .blend files keep working: both editions use the same part data, so scenes made with AngelSTEP open and rebuild in Pro unchanged.

Formats per edition

AngelSTEP and AngelSTEP Pro
STEP (.step .stp)
IGES (.iges .igs)
OCCT BREP (.brep .brp)
AngelSTEP Pro only PRO
Inventor parts and assemblies (.ipt .iam)
CATIA V5 parts and products (.CATPart .CATProduct)
SolidWorks parts and assemblies (.sldprt .sldasm)
Parasolid (.x_t .x_b)
Fusion 360 (.f3d)
JT (.jt)
ACIS (.sat .sab .smt)
Rhino (.3dm)
SketchUp (.skp)

Both editions export STEP. In Pro, every format you import can go out as STEP, so it doubles as a CAD converter.

2 · Import a file

File › Import › CAD: STEP, IGES, BREP (AngelSTEP). In Pro the menu entry reads CAD: STEP, IGES, Inventor, CATIA, SolidWorks, Rhino, SketchUp, ... (AngelSTEP Pro). Or simply drag and drop a supported file onto the 3D viewport. Select several files at once to import them together.

At the top of the dialog's sidebar, the file type list (All supported by default) narrows the file browser to one format.

RECOMMENDED FIRST IMPORT

Import dialog: Check Size result with object count, size and safe starting resolution

1. Check Size. Highlight the file and click Check Size. AngelSTEP reads the file without meshing it and shows the object count, the overall size and a Safe starting resolution for this model.

2. Use. One click puts that resolution into the dialog. The read is cached, so the import right after starts faster.

3. Import. Keep the defaults. You can change every setting per part later without importing again.

FIND TOP ASSEMBLIES PRO NEW IN 3.0

Import dialog sidebar: file type list and the Find Top Assemblies button

A CAD project folder often holds dozens of assembly files, and only one of them is the whole product. Open the folder in the import dialog and click Find Top Assemblies.

AngelSTEP Pro scans the folder and its sub-folders for Inventor (.iam), CATIA (.CATProduct) and SolidWorks (.sldasm) assemblies and lists the top-level ones, those that no other assembly uses, largest first. Each line shows how many parts it holds, and how many of them are missing from the folder.

Click an entry to select that file, then import as usual. Sub-assemblies are counted but hidden from the list.

Assembly files only reference their parts, so keep the project folder together. Parts whose files are missing are left out of the import.

Import options

All import options
  • Resolution: the main quality setting. It is the largest allowed distance between the mesh and the true CAD surface, shown in cm (metric scenes) or inches (imperial). Smaller means finer and more polygons.
  • Min Segments: the fewest facets a full circle gets, so small holes and rounds keep their shape at coarse resolutions.
  • Scale: an extra size factor on top of the automatic mm to metre conversion.
  • Scene Unit Scale: follows Blender's Unit Scale (Scene Properties › Units), so libraries built on "1 unit = 1 inch" get parts at the right size. On by default.
  • Y-up → Z-up: rotates CAD that was exported Y-up.
  • Apply Scale (bake to 1.0): bakes the scale into the meshes, so every object reads scale 1.0 at the same world size. On by default.
  • Heal Shape / Sew Faces: repair dirty CAD and stitch loose surfaces before meshing. On by default.
  • Analytic Mode: how curved faces are meshed, see section 4.
  • Quads: merges clean triangle pairs into quads. On by default.
  • AngelSHADE materials NEW IN 3.0: real materials from the file, see section 3. On by default.
  • Mesh Operations, Patch UV, Remove Holes, Remove Recesses / Bosses, Remove Fillets / Chamfers, Aggressive Removal: the same tools as in the panel, see section 5.
  • Assembly Hierarchy: rebuilds the assembly tree with part names, colours, materials and shared instances. Off gives one merged mesh.
  • Hierarchy to Collections: also sorts the assembly into nested collections. Collection Levels sets the depth, Min Parts per Collection skips one-part branches.

STEP files from Rhino store every object of the model inside one single part. AngelSTEP recognises such files and splits them into separate objects right away, each with its CAD link and its name.

3 · AngelSHADE: real materials NEW IN 3.0

Gearbox straight after import with AngelSHADE: polished steel, brass and cast iron, no manual shading

  • With AngelSHADE materials on, AngelSTEP takes over every material property the file stores: colour, metalness, gloss, transparency, glass and textures, per part and down to single faces.
  • Many files store less, often just a material name. Then AngelSHADE reads the name and fills in what is missing: Steel - Satin becomes brushed metal, Brass - Polished shiny brass, ABS (White) white plastic. The materials keep these names in Blender.
  • Glass comes in as a real transmissive material, not just a transparent colour.
  • Off: colours (and textures) only, on Blender's default surface.
  • Your own materials stay. Swap in any material from your library: it survives every rebuild of the part, and it goes into STEP export.

4 · Mesh modes

AngelFLOW (default, recommended): structured, curvature-following quad grids with the fewest clean polygons. Watertight. The right choice for rendering and visualisation. AngelGRID: an even quad grid over every face, at a Max grid size you choose. More polygons, but uniform density for deforming, displacement and subdivision. Raw: the plain OCCT triangulation without remeshing. A baseline for comparison, and the fallback for damaged geometry.

You can switch the mode of any part at any time in the panel and rebuild it.

Some parts carry no CAD surfaces at all, only a mesh: SketchUp models, mesh-only JT parts, meshes stored in STEP, or bodies the CAD tool already converted to facets. The panel marks them as Mesh part (no CAD surfaces in the file) or Faceted part (mesh-based CAD body). They come in exactly as stored; resolution and mode have no effect on them.

5 · The Live Link panel

Every imported part stays linked to its CAD file. Select a part, press N in the 3D viewport and open the Angel STEP tab. The panel is called AngelSTEP Live Link (or AngelSTEP Pro Live Link). If you prefer the Properties editor, move the panel there under Preferences › Add-ons › AngelSTEP (or AngelSTEP Pro) › Panel Location.

SOURCE AND PART SETTINGS

Panel top: source file and settings for four selected parts

Padlock (next to the part name): Lock Part protects a finished part from every change, including Live Change and batch rebuilds.

Source: the linked CAD file. The folder button relinks the whole import to another file, for example an updated revision; parts that are new in that file are offered with Import New Parts. The refresh button re-reads the current file after it was re-exported. The last button removes the link for good, leaving a plain mesh.

Whole selection NEW IN 3.0: with several parts selected, the heading reads Settings - N selected parts, and every value you change goes to all of them (locked parts excepted). Change a value with fifty parts selected, and all fifty follow.

Mode, Resolution, Min Segments, Quads: as in the import dialog, per part. 0.5 x Details / 2 x Details halve or double the detail in one click. In AngelGRID, Coarser Grid / Finer Grid do the same for the grid size.

Heal / Sew: CAD repair before meshing, per part.

MESH OPERATIONS AND PART INFO

Mesh Operations boxActive Part Info box

Collapse Flat Faces: merges coplanar faces into n-gons for fewer polygons. Off by default; Clean Angle sets how flat counts as flat.

Close Mesh: caps open boundaries. The button turns red when the part has open edges.

Active Part Info: size and triangle count of the part. While a part rebuilds in the background, a progress bar takes the place of the count. Open edges are reported here in red; Show draws them as red lines on the model, and the eye button turns them on or off per part. The same switch, Show Open Edges, sits in the Viewport Overlays menu. Open edges come from gaps in the source CAD; Close Mesh caps them.

Parts with damaged CAD are meshed as raw and say so here. Parts that hold several separate solids show Explode to N Bodies (see Fused Parts below); where AngelSTEP does not know that yet, Check for CAD Bodies looks it up.

DEFEATURING

Defeaturing box

Remove manufacturing detail before it becomes triangles. Everything happens on the CAD geometry, stays watertight, and is also baked into STEP export. It works the same way for every format.

Remove Holes: round holes and counterbores up to Max Ø.

Remove Recesses / Remove Bosses: flush-fills sharp pockets and raised pads up to Max Size.

Remove Fillets / Chamfers: rounds and bevels up to Max Fillet / Chamfer, on turned parts, hole edges and isolated edges on flat faces.

Aggressive Removal (all removals): every tool tries harder and removes features that resist a clean removal. This can leave open edges; the red overlay shows where.

Features are recognised from the finished geometry, not from the CAD program's construction history. Blended, networked or thread-adjacent details are deliberately kept rather than risk a broken mesh.

PATCH UV · REBUILD · EXPORT

Patch UV boxRe-tessellate and export buttons

Create patch UVs: every CAD face becomes its own conformal UV island, packed into the 0 to 1 space, in a UV map named AngelSTEP_UV. Mark UV Seams also marks the face borders as seams. Create UVs on Selected builds UVs for a whole selection without touching the geometry.

Live Change: when on, every change in the panel rebuilds the active part and all other selected parts at once, in the background on every CPU core, while you keep working. Otherwise change the values and click Update all Selected or All (every part of the same source file).

Export Selected as STEP: see section 6.

ASSEMBLY TOOLS

Assembly Tools foldout with Orientation, Collections, Hierarchy, Placement, Fused Parts and Copies

Open the ASSEMBLY TOOLS foldout at the bottom of the panel. The tools work on the whole import of the selected part.

Orientation: switch the import between Z-up and Y-up after the fact.

Collections: Organize Into Collections sorts the hierarchy into nested collections; Dissolve undoes it.

Hierarchy: Prune Hierarchy removes empty or noisy levels. Prune Mode chooses how (leaf empties, small branches or by depth); the ? button shows a diagram. Restore brings the original tree back.

Placement: Move Assembly to World Origin brings far-away CAD data home. Center Origins on Parts puts each selected part's origin at its centre. Both survive every rebuild.

Fused Parts: supplier CAD often arrives as one part that really holds many solids. Explode Selected Parts splits them into separate objects that keep their CAD link, names and materials. If the part is placed more than once, you choose between the selected objects and All Instances of This Part; above 50 bodies AngelSTEP asks before it starts. The original stays hidden and locked until you no longer need it.

Copies NEW IN 3.0: Instance Identical Parts finds every copy of the selected parts in the scene, the same CAD geometry only moved or rotated, that the file did not store as an instance (typical for Rhino files and exploded bodies), and makes them share one mesh. The copies need not be selected; select everything to instance the whole model. Each copy keeps its place, name and CAD link. Only exact copies are matched; locked parts are left alone.

6 · Export back to STEP

  1. Select the objects to export. They can come from different CAD files, and in Pro from different formats.
  2. File › Export › Selected as STEP (AngelSTEP), or Export Selected as STEP in the panel.

Export options

  • AngelSTEP writes each part's original CAD geometry (exact BREP, not the mesh) at the position you moved it to, as one STEP assembly with part and instance names, placements and shared instances.
  • Materials NEW IN 3.0: every part and face material goes out with its name, colour and transparency, including those AngelSHADE filled in and the ones you set in Blender. Glass is written see-through. STEP has no field for metal or gloss; the material name carries them, and AngelSTEP turns it back into the same look when it reads the file again.
  • Export Geometry Edits: bakes hole, recess, boss, fillet and chamfer removal into the exported solids. Off writes the untouched original.
  • Include Plain Meshes: normal Blender meshes in the selection go into the same file as AP242 mesh bodies.
  • Exploded bodies export as separate products, so a fused supplier file leaves Blender as a real assembly.
  • PRO Parts from Inventor, CATIA, SolidWorks and every other Pro format export the same way. SketchUp models and mesh-only JT parts go out as faceted geometry, because that is what they contain.

Mesh edits you made in Blender are not part of the CAD export. Plain meshes export as mesh bodies, not as fitted surfaces; most current CAD packages read them.

7 · Tips and troubleshooting

No import menu after installing? Restart Blender and tick AngelSTEP again in the add-on preferences. "Another AngelSTEP edition is already enabled"? AngelSTEP and AngelSTEP Pro cannot run together. Disable one in Preferences › Add-ons, then enable the other.
Panel missing? Select an imported part, press N in the 3D viewport and open the Angel STEP tab. Parts missing from an assembly? PRO The part files must sit in the project folder. Find Top Assemblies shows how many are missing before you import.
Too many polygons? Raise the Resolution, click 0.5 x Details, remove holes and fillets with Defeaturing, or share repeated parts with Instance Identical Parts. Rounds look faceted? Lower the Resolution or click 2 x Details. AngelFLOW keeps the extra polygons on the curves.
First import slow? Reading a CAD file is a one-time cost. AngelSTEP caches it next to the file, so later imports and rebuilds start much faster. Open edges reported? That is a gap in the source CAD, not a meshing error. Close Mesh caps it.
Parts too small or too large? Check Blender's Unit Scale. With Scene Unit Scale on, AngelSTEP follows it; leave Scale at 1.0. Huge file? Use Check Size first and start at the suggested resolution. Refine only the parts you look at closely.
Want plain colours instead of materials? Turn off AngelSHADE materials in the import dialog. Resolution does nothing on a part? It is a mesh or faceted part: the file stores triangles there, not CAD surfaces.

Questions, tricky files or feature requests? Message me through Superhive. I reply personally.

  • single-user licence

    $25
  • 5 users multi-seat save 10%

    $110
  • AngelSTEP PRO - import 12 formats

    $89
  • AngelSTEP PRO - import 12 formats. 5x users multi-seat save 20%

    $360
$25

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Details
Blender Extension Compatible Yes
Sales 100+
Rating
4 ratings
Dev Fund Contributor
Published 5 months ago
Blender Version 4.2 - 5.2
Extension Type Add-on
Render Engine Used Arnold, Blender-Internal, Blender-Game-Engine, Cycles, Eevee, Freestyle, Luxrender, Mental-Ray, Octane, Vray, Yafaray
License GPL