Model Version Management

Changes made to models are automatically saved, but need to be published to share with other collaborators. Read this article to learn more about model version management.

Introduction

Qonic has a built-in versioning system similar to the git-approach often used in software development. The basic idea is as follows: each BIM model has a public version, the single source of truth for that model at any given time. As soon as someone starts to make a change to the model, a personal version of the model is created for that person; they branch off from the public model to create their own changes. These changes are not visible to other contributors until they are published, or synced, with the public version. After publishing, the public version (the single source of truth) of the model now contains these new modifications.

This approach has several advantages:

• Have an overview of the entire version history of a model. Look back at what a model looked like at a certain date in the past so you can see what has changed in the meantime. This also means you can revert the model back to what it was at a certain point in time.
• Conflict management: if multiple people make conflicting changes to the model at the same time, the system gives you a warning and you can solve the conflict manually if necessary.
• It allows working offline. You can download the model, make your changes locally and when you are ready, push the changes back to the cloud so it syncs back up with the public version.

Accessing the version history of a model

In the dashboard, head to the project model overview. Select a model and click the Versions button.

A dialog will open showing the full version history of the selected model, showing the most recent version at the top. You can select any version, and do any of the following actions:

• Open that version. If the selected model version is not the latest public version, the model version will be opened in read-only mode. 
• Revert to that version. You will not lose any information when doing so; a new version will be created which is a copy of the model version you had selected. 
• Export to IFC.

How to publish your changes

As soon as you have made a modification to a model, a personal version of the model will be created that contains these modifications. You will be notified that your changes are saved in the top-right corner of the screen. To make your changes available to other contributors you will need to publish them. This can be done in the model version history view mentioned above. Navigate there by either:

• clicking the Versions button while you have the model selected in the model overview of the dashboard, see previous paragraph
• clicking the green Publish button in the top-right corner of the screen while you have the model open, see image below.

You should now see your auto-saved version of the model displayed at the top, with the options to either discard or publish the changes. If the Publish button is greyed out, this means your changes are still being synched to the server. Depending on the size of your model, you may need to wait a few seconds or minutes until you can publish your changes.

Once published, your version becomes the latest public version of the model. Anyone opening this model will now see your changes, unless they have changes incompatible with your changes.

Collaborating

It is possible to work with multiple people on one single model at the same time. Because of the asynchronous approach of Qonic's versioning system, you will not see other people's changes appear in your model view in real time. Instead, whenever someone chooses to publish their changes, these changes will become part of the new public version of the model. If you see something like in the image below, this means that someone has recently published their changes and the server is still processing this.

One of two scenarios is now possible:

• The changes that were made by the other person do not conflict with your own changes. You don't need to worry about anything - Qonic will automatically sync these changes. If you now open up the model again, you will see the other persons changes as well as your own (note: you will still need to publish your changes for other people to see them).
• The changes that were made by the other person conflict with your own changes. You are notified by this conflict in the version history panel.

When this happens, you can resolve this conflict by either discarding your changes or by keeping your changes.

• Discard your changes: you will lose all the changes you have made since you last published this model. 
• Solve conflicts: open the model in a dedicated 'conflict solving' mode. Here you will see a list of all conflicting changes, with an option to choose between the two versions of each change. On the left-hand side you will see your own version of the change, on the right-hand side you will see the latest public version of the change. You can solve each conflict individually by clicking either of the two options. Once all conflicts have been resolved, the 'conflict solving' mode will be closed and you can continue working as normal.
  
  

Revisions

Qonic supports uploading revisions of IFC files in the same version history of a model. In the version history of a model, click Upload Revision in the bottom left of the screen. 

When uploading a revision, Qonic will not simply overwrite the previous version of the model. Instead, it will try to merge the changes that were made in Qonic and those that were made in the new IFC file. This way you can in fact simultaneously work in your original BIM authoring of choice and in Qonic, and use the version history in Qonic to manage and keep track of all these changes. If there are conflicts between changes made in Qonic and those made in the new IFC revision, the same conflict resolving method as described above will be available.