Supported formats

Kapnetix Post reads the common motion-capture interchange formats and writes back standard, editable files that drop straight into your pipeline. Format and tags are detected on upload — you do not pick the type by hand.

Format	Source	Read	Export
FBX	Autodesk (Maya, MotionBuilder)	✓	Keep original
C3D	Marker-cloud standard	✓	Keep original
BVH	Skeleton / hierarchy	✓	Keep original
TRC	Marker trajectory (Motive / OpenSim)	✓	Keep original
TAK	OptiTrack Motive	✓	Keep original
VDF	Vicon Shōgun	✓	Keep original

Every supported format round-trips in its own format. In the Export dialog the option reads Keep original (C3D), Keep original (VDF), and so on.

Convert is visible but switched off — it reads Convert · soon. Converting between formats on export is still to come; until it lands, use Keep original.

The rule behind all of it

Where Post can, it writes your clean by patching your own file instead of building a new one from what it loaded. Everything the file carried that Post does not need to touch is still there afterwards, because it was never rebuilt.

What that preserves depends on the format — the sections below. What it does not change, in every format: the solved skeleton inside the file is the one you uploaded. Post is a marker-space cleaner. A solve made from the uncleaned markers no longer matches them once they are corrected, so the deliverable needs a re-solve in your own tool for the corrections to reach the rig.

C3D

A cleaned C3D is written by patching your uploaded file: the corrected markers go into the channels their labels already occupy. Channel order, every parameter group, the header and the analog block are your file's own, because none of it is rebuilt. A pipeline that addresses markers by channel index gets back the channels it sent.

A save that changes nothing returns a file byte-identical to the one you uploaded. Template channels that no cleaned performer claims are left untouched.

One limit worth knowing: positive residual magnitudes and camera masks do not survive a C3D write, patched or not. The point block is re-encoded and only the "invalid sample" marker is carried through, which is what a gap needs and all it needs.

If your original is not available at export time, the C3D is rebuilt from the markers instead — and the export note says so:

Rebuilt from the markers alone — your channel order and parameter groups are not preserved.

TAK and VDF

TAK (OptiTrack Motive) and VDF (Vicon Shōgun) come back as TAK and VDF. Both are proprietary containers with no public specification, so Post does not author one from scratch: it patches the cleaned marker animation into a byte-for-byte copy of the file you uploaded. Your header, calibration, cameras and processing metadata survive untouched, and a no-op save returns the file you gave us.

Validated by opening the exports in MotionBuilder, Maya and Shōgun.

Because the container is copied, the solved skeleton inside it is copied too — unchanged. The export dialog says so:

Cleanup corrects the marker data; the solved skeleton in this file is unchanged. Re-solve in Shōgun to see corrections on the rig.

and, for a TAK, Re-solve in Motive.

These two are the one case where the original file is required. Without it there is nothing to patch, so the export falls back to FBX and the note explains the swap — see the export note.

FBX

An FBX is patched the same way when your uploaded file is available: only the marker translation curves (and, where present, the occlusion channels) are replaced, so your rig, props, scene graph, node names and properties survive.

Two limits:

• A rig-bearing, solved skeleton is not patched. A solve goes stale the moment markers move, and re-solving belongs in your tool, so a rotation-bearing skeleton is refused rather than written over. That take comes back as a fresh build with its animation intact.

• Without your file, an FBX is rebuilt from the markers, and the export note says what that costs:

  Rebuilt from the markers alone — your rig, props and scene graph are not in this file.

BVH carries a solved skeleton and no optical marker cloud, so there is no marker cleanup to plan for it. The Cleanup Plan column says Nothing to plan for those takes.

The export note

Post never delivers a file that is not what you asked for without saying so. There are three sentences you may see, and silence when nothing was substituted.

The format changed. What you asked for, what was written, and why, in the cleaner's own words:

You asked for VDF; this Clean version was written as FBX. VDF needs the original file as an export template; none available.

The format changed and nobody said why. The served file's own extension disagrees with what you uploaded, and no explanation came with it:

This file was written as FBX, not the VDF you uploaded. The cleaning worker did not say why.

The format is right but your file was not used as the template. A fidelity note, not a format change — the two never stack:

Rebuilt from the markers alone — your rig, props and scene graph are not in this file.

Rebuilt from the markers alone — your channel order and parameter groups are not preserved.

Either of the "rebuilt" lines may be followed by the reason the template was not used, for example No source file available to patch.

The same notes appear on the take's version history, so a Clean version carries its own export story rather than only the dialog you happened to have open.

What Post does not promise

• No format conversion on export yet. C3D → BVH and friends are still to come.
• No solving. See the re-solve note above; this is a division of labour, not a gap.
• Joint layers are re-derived, not copied, where they are written at all — marker data is exact, bone animation is faithful rather than bit-identical.
• Nothing is written over your raw capture. Every clean is a new Clean version.

Capture systems and frame rate

Post works with takes from Vicon (including Shōgun .vdf), OptiTrack (including Motive .tak), and markerless capture.

Frame rate, duration, marker count, actor count and capture system are read from the file itself and shown on the take's stats panel after diagnosis. Nothing is assumed.

What to do next

Upload one take in the format your pipeline actually uses, clean it, export with Keep original, and open the result in your own tool before you commit a whole shoot day.

Ask us

Something looks wrong on a take? Write to support@kapnetix.ai and send the take id, or the take's name and the project it sits in.