LWS to STEP Converter
FileFlip converts LWS to STEP entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an LWS file to STEP?#
- Drop your LWS file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to STEP and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the STEP file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting LWS to STEP lose quality?#
Not in the sense of pixels or samples. Converting LWS to STEP rebuilds the file in STEP's own model rather than re-encoding it, so everything STEP can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert LWS files online?#
Yes, because nothing is uploaded. FileFlip converts LWS files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What LWS to STEP actually does to the file#
Converting LWS to STEP runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model, and drops skeleton and animation.
| Engine | Assimp |
|---|---|
| Conversion path | One step: LWS → STEP |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- if the source carries a skeleton or animation, this target has no place to store it
What is an LWS file?#
An LWS file is a NewTek LightWave scene, a plain-text list of the LWO objects it loads along with the cameras, lights, item hierarchy and keyframed animation that arrange them.
Keep a scene as LWS while it's still being lit, animated and arranged inside LightWave's Layout.
Convert LWS to FBX or glTF once the arranged scene needs to move into a game engine or another DCC tool.
What is an STEP file?#
An STP file holds a STEP product model in ISO 10303's plain-text exchange syntax, encoding exact boundary-representation solids, surfaces and curves rather than a triangulated mesh.
Use STEP whenever exact CAD geometry, not an approximated mesh, needs to move between two different CAD systems.
Convert a STEP file to a mesh format like STL or OBJ once the model is finished and only needs to be viewed, rendered or 3D printed rather than edited as a solid.
LWS to STEP questions people ask#
What is an LWS file?
An LWS file is a LightWave scene: a plain-text file that lists the LWO objects it uses and adds the cameras, lights, parenting and animation that arrange them in Layout, LightWave's animation and rendering module.
Can I open an LWS file without the LWO objects it references?
Not usefully. An LWS file stores references to LWO object files by name rather than the geometry itself, so LightWave (or any other LWS reader) needs those LWO files in the expected location to reconstruct the scene.
Is LWS the same as an LWO file?
No. LWO holds a single object's geometry and surfacing, while LWS is the scene that arranges one or more LWO objects with cameras, lights and animation. The two formats are a pair: an LWS file is only complete alongside the LWO files it loads.
What does STP stand for?
STP is the file extension for STEP, the Standard for the Exchange of Product model data, formally ISO 10303. It's the neutral format mechanical CAD systems use to hand solid models to each other.