Comparison
WWD against six existing formats
3MF Core, 3MFBio, STEP AP242, STL, SBML and SBOL 3. WWD 0.1 does not replace any of them. It delegates geometry, print process, computational models and genetic constructs to them and states which representation is authoritative.
Scope of each format
What it covers, its status, and how a WWD package uses it.
| Format | Scope | Status | Relationship to WWD |
|---|---|---|---|
| 3MF Core | Additive manufacturing package: OPC/ZIP container, watertight printable geometry, defined units, extensionsUsed and extensionsRequired refusal semantics. | ISO/IEC standardised. Many shipping implementers. | WWD delegates geometry to it. A 3MF part may carry authoritative geometry inside a WWD package. |
| 3MFBio | XML extension of 3MF for bioprinting and pharmaprinting print jobs. Bioink viscosity, cell viability, material composition, CAS numbers, thermal stability, cartridge type, gauge size, environmental controls, and workflow steps from pre-print mixing to post-print curing. 35 or more defined attributes. | Open source, developed by Brinter AM Technologies, under development. Regulatory alignment claimed with ISO 10993 and FDA guidance. One vendor implementer. | A WWD protocol step may delegate to a 3MFBio or 3MF part inside the package or to an external asset with integrity. |
| STEP AP242 | Product model exchange for mechanical parts: topology, product manufacturing information, tolerances. | ISO standardised, in wide industrial use. | Named as one of the geometry formats a WWD consumer may support. Where STEP semantics are available they are retained rather than flattened to STL. |
| STL | Triangulated surface shape. No units, no topology semantics, no named regions. | De facto, universally read. | Permitted as a WWD geometry payload for surface shape. It may not be the sole carrier of units, topology semantics, regions or interfaces. |
| SBML | Systems biology models: species, reactions, compartments, kinetic laws. | Community standard with a large tool ecosystem. | A WWD simulation model may reference an SBML asset. WWD carries the model envelope and the run record and does not solve. |
| SBOL 3 | Genetic construct design: sequence, features, interactions, construct hierarchy. | Community standard, versioned. | A genetic construct is referenced through an SBOL document or a stable SBOL identity. WWD does not duplicate SBOL sequence, feature, interaction or construct semantics. |
Capability matrix
One row per capability. Read across.
| Capability | 3MF Core | 3MFBio | STEP AP242 | STL | SBML | SBOL 3 | WWD 0.1 |
|---|---|---|---|---|---|---|---|
| ZIP container, units, extension refusal | yes | yes, inherited | not applicable | no | not applicable | not applicable | yes |
| Watertight printable geometry | yes | yes | yes | surface only | no | no | delegated to 3MF, STEP, glTF, STL or VTK |
| Bioink and material parameters | partial | yes | no | no | no | no | delegated to the protocol |
| Printer process settings | via Production extension | yes | no | no | no | no | delegated, may be a 3MFBio part |
| Spatially varying property fields | no | no | no | no | no | no | yes, five backings and one evaluate contract |
| Fibre alignment as director plus order parameter | no | no | no | no | no | no | yes, with tensor conversion |
| Biological identity via CL, NCBITaxon, Cellosaurus | no | partial | no | no | no | partial, sequence identity | yes, delegated and required |
| Genetic construct semantics | no | no | no | no | no | yes | referenced, never duplicated |
| Reaction network and kinetic model | no | no | no | no | yes | no | referenced as a delegated model asset |
| Statistical acceptance criteria with assay method | no | no | no | no | no | no | yes, closed vocabulary |
| Yield as a first-class parameter | no | no | no | no | no | no | yes |
| As-built measured results linked to criteria | no | no | no | no | no | no | yes, derived rather than flagged |
| PROV lineage from cell bank to lot to specimen | no | no | no | no | no | no | yes |
| Validity window, time as part of identity | no | no | no | no | no | no | yes |
| Control against response, the causal axis | no | no | no | no | no | no | yes |
| Non-printed modalities such as MEA culture and organoid | no | no | no | no | not applicable | not applicable | yes |
| Manufacturability design rules | no | no | tolerancing | no | no | no | yes, 11 rules |
| Regulatory alignment | not applicable | claimed, ISO 10993 and FDA | not applicable | not applicable | not applicable | not applicable | none |
| Standards body | ISO/IEC | none | ISO | none | community | community | none |
| Shipping implementers | many | one vendor | many | many | many | several | one repository |
Two different questions
The models differ before the feature lists do.
The 3MF causal model is the additive-manufacturing model: instructions go to a machine, the machine deposits material, the artifact matches the model, and deviation is machine error. 3MFBio extends the parameter half of that model with bioink and cartridge description. That model holds for the deposition step.
A printed construct is seeded rather than finished when the printhead stops. Fusion, alignment, matrix remodelling, network formation and maturation follow, and the printer does not cause them. 3MFBio can state an extrusion at 22 degC through a 25 G nozzle at 12 mm per second. It has no slot for a fibre alignment target of S greater than or equal to 0.65 by day 14 measured by structure tensor over 5 fields, for a median twitch force criterion at n = 12, for the distinction between a value the producer set and a value the tissue produced, or for what a lot measured.
3MFBio answers how a print job is reproduced on another machine. WWD answers what living component is being ordered, how both parties will know it worked, and what the build measured. A bioprinted WWD component delegates its fabrication protocol to a 3MFBio file.
Where the incumbent is ahead
From the critique, unchanged.
| Area | Position |
|---|---|
| Regulatory alignment | 3MFBio claims alignment with ISO 10993 and FDA guidance. WWD has none. The WWD acceptance-criteria model can carry ISO 10993 assay references, and nobody has mapped them. Recorded as a named gap. |
| Industry sponsor | 3MFBio has a vendor shipping bioprinters. WWD has one implementer, the reference repository. |
| Standardisation | 3MFBio inherits packaging, geometry, units and extension semantics from ISO/IEC-standardised 3MF. WWD re-derived equivalents and they are not standardised. |
| Tooling ecosystem | lib3mf, slicers and CAD exporters already read the 3MF container. WWD software reads WWD files only. |
| Shipped attribute list | 3MFBio ships 35 or more named attributes a vendor can implement. The WWD Core property registry holds 58 terms and registry breadth is deferred. |
| Schema language | 3MFBio uses XML and XSD. WWD uses JSON and JSON Schema. The XML question is recorded as closed for 0.1. |
| Scope | 3MFBio has a narrower scope and can be completed. The WWD scope is large, and the critique records scope discipline as the top project risk. |
The critique records one demonstration of the delegation architecture:
bioprinted-strip.wwd carries an embedded 3MF part with integrity and the role
opaque, and validates with zero errors and zero warnings.
- The bioprinted example package, which delegates to an embedded 3MF part.
- Section 6 of the draft, delegated geometry and asset formats.
- The .wwd file format reference.