Importing models

Bring work from Rhino, Matrix, ZBrush, Blender — anything that exports a standard mesh format.

Supported formats

Format	Notes
GLB	The recommended interchange: one binary file, everything embedded.
GLTF	Single embedded file only — external buffer/image references are rejected. Export as GLB or "glTF Embedded" instead.
Rhino .3dm	Imports mesh geometry including the render meshes embedded on Breps and extrusions, and converts Rhino's Z-up to Y-up. A pure-NURBS file without render meshes needs to be saved from Rhino with shaded render meshes embedded (open it in a shaded viewport, then save).
STL	Binary or ASCII. Jewelry-CAD Z-up is converted to Y-up, curved shading is rebuilt while sharp edges are kept. Arrives as a single part — see Auto separate below.
OBJ	Object/group names become separate parts. Material sidecars aren't resolved — GemGpu applies its own materials, which is the point.

Pavé and multi-stone pieces are welcome: stone-heavy models are budgeted per stone, so an 80-stone ring imports as readily as a solitaire.

Open vs Import

Open model (File ▸ Open model) — replaces the scene with the new file as a fresh base.
Import model (File ▸ Import model, the Import file button, or drag-and-drop) — appends to the loaded scene as another top-level group. With no model loaded, it becomes the base. This is how you compose: a ring from one file, a display prop from another.

Importing a second file appends it as its own group in the hierarchy.

If an import fails, your previous scene stays untouched.

What happens on arrival

Normalization — the model is centered and uniformly scaled to a consistent studio size, whatever units it was authored in. This is stable: re-saving and re-loading never drifts scale or position.
Classification — parts are recognized as gems or metals and tagged in the hierarchy. If something is misread, right-click the part and change its kind.
Studio look — a first import applies the default environment, lighting, and material templates so the piece arrives lit, not grey.

One-part files

STL merges everything into a single part — the format has no part structure. To work per-stone in GemGpu, export from your CAD with parts intact: GLB keeps objects separate, OBJ keeps object/group names, and Rhino users can use the Live Link (block instances arrive as individual parts).

Scene ▸ Auto separate parts is a classification pass, not a splitter: it re-examines every existing part's shape and name and corrects its gem/metal kind — useful when an import guessed wrong across many parts at once. For a single part, right-click ▸ set kind does the same thing faster.

Scene files and bundles

Beyond model files, GemGpu has its own documents:

Scene settings (.json) — everything about the scene (materials, environment, camera, animation, image grade) without model geometry. Small, portable, applies to whatever model is loaded.
Scene bundle (.zip) — settings plus your imported model files and custom HDRIs. The self-contained handoff: send it to a colleague and it opens complete.

Both open via File ▸ Open scene (.json / .zip) and download from the Drive tab or File menu.

Where your model bytes live

Imported geometry stays on your device by default — model files are never uploaded on their own. Two explicit exceptions, both yours to trigger:

Save model to Drive (Scene tab, signed in) — uploads that model so your scenes restore complete on other machines.
Scene bundle download — packs the bytes into a .zip on your disk.

Export

File ▸ Export visible GLB writes the currently visible parts as a GLB — useful for taking a cleaned, regrouped model back to other tools.