CharacterStudio Motion .csm
Raw optical marker data for 3ds Max’s Character Studio.
What a .csm file holds
CSM holds the positions of optical motion-capture markers over time: data straight off the cameras, before it has been fitted to any skeleton. It was Character Studio’s input format in 3ds Max, where a biped rig would be solved against the marker cloud.
Commonly seen in: 3ds Max Character Studio, optical mocap systems.
| Data | Stored in CSM |
|---|---|
| Geometry | No |
| Materials and colour | No |
| Texture maps | No |
| Animation and rigs | Yes |
| Scene hierarchy | Yes |
| Read here | Yes |
| Written here | No |
Tested against a real file
The last sweep loaded ThomasFechten.csm from Assimp test models with its 1 sidecar files through the viewer on this site: 352 triangles across 1 meshes and 1 materials, in 3.4 seconds. Every format's result is on the test results page, run 2026-09-08.
Convert CSM to another format
Every pairing has a page saying what survives the trip.
Other things to do with a .csm file
Questions about CSM
How do I open a .csm file?
Drop it into the viewer on this site and it opens in the browser, with the scene tree, the materials and the mesh statistics. Nothing is uploaded. If you want it in another program instead, convert it to GLB, which almost everything reads.
Is CSM a good format to archive in?
CSM stores animation and rigs, scene hierarchy. Anything outside that list will not be in the file at all, so archive the original alongside it if the surfacing or the rig matters.
Does converting CSM lose quality?
Geometry is copied vertex for vertex, so the shape does not degrade. What gets lost is whatever the target format has no field for: convert to STL and the materials go, convert to OBJ and the animation goes. The comparison table on each converter page says exactly which.
Formats that hold the same things
Or go back to the full format reference.