CAD — read by a geometry kernel
Render a STEP file into product photos, in your browser
STEP is the format every CAD program can export and the one Rendermio reads best. Drop a .step or .stp file in, and it is converted on your own machine by a real geometry kernel — curves stay curves, parts stay separate, and nothing leaves your browser.
How Rendermio reads STEP
Accepted as .step, .stp. STEP, IGES and BREP go through a real boundary-representation kernel — OpenCascade, compiled to WebAssembly and run inside the page. The kernel reads the exact surfaces, then tessellates them at a tolerance tuned for jewellery (a bounding-box ratio of 0.0002 and an angular deflection of 0.12 radians), which is far finer than a viewer's default. That is why a curved band renders as a curve and not as a polyline of visible flats. STEP is the format this path was built around: it carries exact geometry, part boundaries and usually part names and colours, so a multi-part assembly arrives as a list of parts you can dress one at a time.
What comes through
- Exact curved surfaces, tessellated finely enough to stay curved at 8K
- Every solid as its own part, so a band, a head and each stone can take different materials
- Part names from the file, which the studio uses to guess which parts are stones
- Assembly structure and real-world scale
What does not
- Appearances are approximate — STEP colours are read, but PBR materials are not something STEP can carry, so you choose a metal or stone in the studio
- Sketches, constraints and feature history: STEP is geometry only, and so is a render
Exporting STEP from your CAD program
- Export as STEP AP214 or AP242 rather than AP203 — those carry colours and names, AP203 does not
- Export the solid bodies, not surfaces: an unclosed surface body has no inside and can render inside-out
- If a file refuses to open, re-export it as AP214 from the original program; that fixes most of them
STEP files typically come from SolidWorks, Fusion 360, Onshape, CATIA, Creo, Inventor, NX, FreeCAD, Rhino, MatrixGold. Working in SolidWorks, Fusion, CATIA, Inventor or Creo? Their native files are not readable in a browser — here is what to export instead.
Then what happens
Once the file is in, the steps are the same for every format: tell the studio what the object is, and it dresses it — one click finds the stones in a ring and makes the rest gold. Pick a Look, which sets lighting, backdrop, pose and camera together. Export a listing pack up to 8K or a 360° turntable video. Everything runs on your own GPU; the file never leaves the page.
Questions
Can I render a STEP file without installing CAD software?
Yes. Rendermio converts and renders the STEP file inside your browser using OpenCascade compiled to WebAssembly, so there is nothing to install and the file is never uploaded. You need a desktop browser with WebGL 2 — Chrome, Edge, Firefox or Safari.
Will the curves in my STEP file look faceted?
No. The kernel tessellates the exact surfaces at a tolerance tuned for jewellery, far finer than a viewer's default, so a ring's band renders as a smooth curve even at 8K. Faceting is a symptom of mesh exports like STL, not of STEP.
Which STEP version should I export?
AP214 or AP242. Both carry part colours and names; AP203 carries geometry only. If a file will not open, re-exporting as AP214 from the original CAD program resolves most cases.
Free · runs in your browser · your file is never uploaded