File formats

Native project format — .pvo

Ortho's own editable format is version 1 and has remained compatible across releases. Open validates before replacing the document; invalid files are rejected without discarding current work. New/Open are undoable in this release.

TIP

Save a .pvo copy for reliable persistence — the IndexedDB recovery copy is removed when browser site data is cleared.

Export bundles

Bundle	Contents
OBJ bundle	OBJ + MTL + texture PNG in a ZIP. A static scene snapshot.
glTF bundle	glTF + bin + texture PNG in a ZIP (gltf2.ts implementation).
Texture PNG	The 128×128 indexed atlas, expanded to RGBA.
Rendered PNG	Scene render, configurable up to 2048px per axis.
Animated GIF	Timeline-driven or turntable; duration follows the timeline (turntable: frames/fps).
Sprite sheet	Packed frames with companion JSON settings.

Export effects (0.3.0)

Exports → Animated GIF / Rendered PNG / Sprite Sheet → Pixel effects:

• Silhouette outline — 1–4 output pixels, arbitrary opaque RGB color, bounded edge clipping. A two-pass Chebyshev dilation of the original transparent scene mask avoids recursive growth and never outlines the background itself.
• Scanlines — color, strength 0–1, interval 2–8 output rows. They affect the composited image but never fill empty transparent areas.
• Pixel tags — bottom-left/right uppercase 5×7 bitmap letterforms, independent RGB colors, scale 1–4, 48-character input limit. Lowercase is displayed as uppercase; unsupported characters become question marks. Tags truncate into disjoint halves when both are present.
• Pipeline order is outline → background/transparency → scanlines → tags; text stays legible above scanlines. PNG and sprite exports use the same renderer as GIF frames.
• Decorated GIF exports extend the global palette to preserve exact effect/background colors while retaining transparency (up to 256 colors). Overflow is explicitly warned and mapped to nearest colors.

glTF fidelity notes

glTF supports sampled transform animation with pivot-correct local nodes. The following are not standard glTF semantics and produce named warnings: visibility clips, draw-behind, retro affine interpolation, shade ramps and retro post effects.

Camera & frame capture

PNG/GIF/sprite capture supports perspective/orthographic cameras, yaw/tilt, distance, target XYZ, FOV/orthographic height, background and turntable start/direction. Use current view copies the last focused viewport camera pose/projection; output dimensions define the aspect ratio. Fit-model recenters off-origin scenes. Live previews use the exact output resolution, support scrubbing/playback, and match saved-frame pixels.

Frame batches are bounded to 64 MiB, 120 frames and 512px frames; encoding runs on the main thread after rendering and cancellation is effective during capture.

What is not supported

• Third-party native formats (FBX, DAE, …) are not supported — only .pvo.
• No collaboration or skeleton rigging.

The hosted production app includes a service worker and installable PWA offline shell. See Installation & running for setup and the distinction from the standalone HTML preview.