Migrate Older Version Projects to Cubism 4 SDK

This page is for Cubism version 4.2 or earlier. Click here for the latest version.


In this page, we will explain the advantages and disadvantages of migrating from the previous versions of the Cubism SDK, Cubism 3 SDK and Cubism 2.1 SDK, as well as a simple flow example for the release of the Cubism 4 SDK.

Before we begin, the handling of the Cubism 3 SDK and Cubism 2.1 SDK after the release of the Cubism 4 SDK is as follows.

  • New downloads will be prohibited and no further updates will be made
  • No new features will be supported in the future
  • Defects are targeted individually and corrected only when a defect is reported

Migrate from Cubism 3 SDK to Cubism 4 SDK

The following are the advantages and disadvantages for users of the Cubism 3 SDK when migrating to the Cubism 4 SDK.


  • New functionality is available (mask inversion) Note: The frame step function and extended interpolation can be used for embedded data exported by Cubism 3 or equivalent.
  • Models created with Cubism 3 Editor can be used without modification (backward compatibility)


  • None

Flow example

The structure of the Cubism 4 SDK is basically unchanged from the Cubism 3 SDK. When migrating SDKs, after replacement, you can use them by rebuilding them if necessary.
When using the sample code as it is at the time of SDK migration to verify operation, the third-party libraries used in the sample code may have been updated or the directory structure may have been changed.
See the README and CHANGELOG for each platform of the Cubism 4 SDK for details.

Migrate from Cubism 2.1 SDK to Cubism 4 SDK

The following are the advantages and disadvantages for users of the Cubism 2.1 SDK when migrating to the Cubism 4 SDK.


  • Improved maintainability by extending the scope of SDK source release
  • Many functions not implemented in 2.1 are now available, enabling even richer expression
  • Because all parts other than the Core are open source, almost all customization, including the renderer part, can be done freely
    Note: Please note that this requires acceptance of the Live2D Opensoftware License.


  • High cost of transition
    • Need to replace a complete set of SDKs
    • Data for model incorporation needs to be re-exported to the latest format
      Depending on the model, there may be work to be done to correct the data before re-exporting the data for model incorporation. The details are given in the flow example.

Flow example

When migrating from the Cubism 2.1 SDK to the Cubism 4 SDK, be sure to read the .cmox and .canx files in the Cubism 4 Editor and export them to the Cubism 4 SDK built-in data.

In addition to replacing the SDK and model data, there may be other work to be done to make the geometry and operation compatible.
The following is a description of possible work and how to deal with it.


When the deformation and drawing results of the migrated model are different

The model will need to be adjusted.
Load the .cmox file to be migrated in the Cubism 4 Editor and adjust the deformation results.
After adjustment is complete, export the .moc3 file and check the display on an actual device equipped with the Cubism 4 SDK.


About mtn files (motion files) used with the Cubism 2.1 SDK

The Cubism 4 SDK does not support .mtn.  However, since the Cubism 4 Editor can read .canx files, this can be dealt with by exporting the loaded .canx to motion3.json.
However, the motion curve cannot be completely reproduced, and changes in the values on the timeline are processed to create a curve with approximate values.


About support for physics operations

Physics operations used in Cubism 2.1 cannot be used in the Cubism 4 SDK without modification.
For models using Cubism 2.1-created physics, please set up the physics again in the Editor.


About parameter IDs

The IDs of parameters specified in the Cubism SDK for breathing, eye tracking, etc. have been changed to Cubism 4 specifications.
When migrating models used in Cubism 2.1, please convert them to Cubism 4 specifications at the time of export.

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