file-viewer/docs/en/guide/format-fidelity.md

Format Fidelity

Clear Capability Boundaries

Flyfish Viewer documents what is fully rendered, what is structurally inspected, and which formats need specialist engines for perfect fidelity.

High-confidence Preview Lines

• PDF, OFD, images, audio, video, Markdown, source code, text, JSON/YAML/TOML/XML/SQL, archives, email, EPUB, Mermaid, Excalidraw, draw.io, and common Office/OpenDocument files.
• CAD preview is powered by @flyfish-dev/cad-viewer through @file-viewer/renderer-cad; DWG, DXF, DWF, and DWFx assets stay self-hostable.
• Word preview uses @file-viewer/renderer-word and the self-maintained @file-viewer/docx path for readable stream-style DOCX rendering.
• Presentation preview uses @file-viewer/renderer-presentation and the standalone @file-viewer/pptx engine.

Structure-first Lines

Some engineering formats are intentionally conservative:

Format family	Current behavior
OLB / DRA	Safe structure preview for common OrCAD / Allegro containers and readable metadata
OAS / OASIS	Readable fixtures render; complex binary OASIS stays structure-index focused until the dedicated layout kernel matures
STEP / IGES / IFC / 3DM / BREP	Signature detection and conversion guidance, with visual support delegated to dedicated WASM engines
PlantUML	Offline source/SVG-style preview by default; configure an intranet PlantUML service for full server-rendered SVG

Verification

Use the built-in checks when the format matrix changes:

pnpm verify:format-support
pnpm verify:smoke-matrix
pnpm verify:renderer-assets