3Di Ecosystem

The 3Di Ecosystem consists of the following five components:

  • 3Di Modeller Interface: a QGIS based environment where schematisations can be build and edited.

  • 3Di Livesite: a web application to start, pause and adjust simulations.

  • 3Di Management Screens: an online overview of your schematisations, models and simulations.

  • 3Di Computational Core: a Fortran software package which handles the hydrodynamic calculations.

  • 3Di API: an application programming interface, which enables other applications and user interfaces to interact with the computational core.

All components are secured by an Authentication and Authorisation system. This will be discussed in the Authentication and User Management section.

3Di Ecosystem

Fig. 1 The 3Di Ecosystem.

3Di Modeller Interface

The Modeller Interface is a customized version of QGIS, a software tool used by hydrology experts to build and edit models, start simulations, and analyze their results. It comes with a number of pre-installed plugins, including the 3Di Models and Simulations and the 3Di Toolbox, which are custom-made for use with 3Di. The 3Di Models and Simulations plugin allows users to complete a full modeling workflow, including uploading their model, starting a simulation, and downloading and analyzing the results, all within the Modeller Interface. The 3Di Toolbox, on the other hand, is used for importing schematizations, checking data, and analyzing results. This setup allows users to take advantage of the processing power of QGIS while using the specialized 3Di plugins to create, simulate, and analyze their models.


For more information on installing the Modeller Interface, please refer to our Installation manual. The basics of the Modeller Interface are explained in the Workflow Tutorial. For the experienced modellers, the How to work with 3Di section covers the more in depth applications of the Modeller Interface.

3Di Modeller Interface

Fig. 2 An example of a schematisation in the Modeller Interface.

We have chosen QGIS as our supporting platform because of the following reasons:

  • QGIS comes with hundreds of powerfull GIS processing tools;

  • It enables the combination of web maps (aerial, topo, osm and may others) and model schematisations;

  • It offers an exstensive amount of styling options;

  • It has a highly customisable interface

  • The option of building your own plugins to interact with the model;

  • The fact that it is an open source platform.

3Di Livesite

On the Livesite you can start, pause and adjust your simulations. This is the key to interactive and visual modelling, which is essential for a shared understanding of watersystems. A scientific paper on the importance of a shared understanding can be found here.

The video below gives a brief demo of the Livesite. For more detailed information, visit the Livesite page.

A demo of the 3Di Livesite

3Di Management Screens

When using the Modeller Interface, schematizations are stored locally on your computer. However, if you use the Model and Simulations plugin to upload a schematization, it will be saved to our private cloud. These uploaded schematizations can be accessed and viewed in the Management Screens. In addition, all relevant information about revisions, 3Di models, and simulations related to the schematizations can be found in the Management Screens. This allows colleagues to sync their models on their own laptops and continue working with the updated version, enabling the use of version control on your schematizations.

The Management Portal can also be used to manage 3Di models, start simulations from simulation templates, monitor running simulations, and download results. This web-based portal is designed to provide users with the tools and information needed to perform day-to-day tasks efficiently.

A more enhanced use of the Management screens is described in the Management Screens manual.

The management screen homepage

Fig. 3 The homepage of the Management Screens.

3Di Computational Core

The computational core handles the hydrodynamic calculations after a simulation is started. These calculations run on specialized servers to ensure computational power. Please visit the Physics and the Modelling Concepts pages to read more about the science that underlies the Computational Core.


Our REST API is the center of the 3Di Ecosystem, which serves as communication between all interactions of users and forcings and the functionality of 3Di. If you are only interested in using the above mentioned tools, no extra attention to the API is required. However, the API can be used if you want to connect your favourite tools (Jupyter Notebook, Matlab, Power BI etc.) or programming language to 3Di. This gives you a lot of flexibility to your modelling applications and can save you lots of manual work and time. Some examples of applications of the API are:

  • Batch simulations: run hundred different rain events.

  • Automated testruns, results checks and adjustments to a model before running another simulation.

  • Run 3Di in an operational system, such as a Flood Early Warning System.

  • Use Jupyter Notebooks to run, download and analyse your 3Di simulations. Examples can be found on the 3Di github repository.

  • Design your own control for weirs or other structures.

The API Root can be found on https://api.3di.live/v3/. More enhanced information on the API is written in the Swagger version, where each endpoint contains a block of documentation.

Authentication and User Management

Signing up

New users require an invitation to create a 3Di account. Users with a ‘manager’ role within an organisation are able to send invitations. If you do not know whom to contact, please contact our Servicedesk at servicedesk@nelen-schuurmans.nl.

If you have received an email from either a manager within the organisation or the servicedesk:

  1. Open the invitation link in the email.

  2. Click on ‘Sign up’ and fill in the required fields. Please use the same email as the invitation was sent to. Using another email will not work.

  3. Check your email for the required verification code.

  4. You should now be redirected to the API root. This means you have created a 3Di account and have access to the organisation.


If you see a 403 error after openining the invitation email, please try to open the url in an incognito window before reaching out to the Servicedesk.

Signing in

Users can login in either the Modeller Interface, the Livesite, the Management Screens and the API. Except for the Modeller Interface, all 3Di components will redirect you to the following login screen:

The login screen

Fig. 4 The login screen.

If you do not have an account yet, please read ‘Signing up’ first. If you do have an account, you can either log in by using your company account or by using your credentials, in case your company is listed on the left part of the login screen. Loging in via your company account is the preferred option. Existing users should use the same method as they used when signing in for the first time.


Due to our authentication update in May 2022 it might occur that you cannot log in anymore. Please use the ‘Signing up’ guide to create a new account.


Do you want to add your company to the list to centralise the user accounts of your organisation? Please contact our support office (servicedesk@nelen-schuurmans.nl) for the options.

User management

The User Management interface.

Fig. 5 The User Management interface.

Users can be managed in the User Management interface. This interface can be reached via https://api.3di.live/management/users/. The example above shows the list of users in the example organisation ‘3Di Test’, with for each user options for 4 roles. These role are desribed as:

  • A Viewer, who can only read data and follow simulations

  • A Simulation runner, who can read data and run simulations

  • An Creator, who can read data and can add, change or delete schematisations and 3Di models

  • A Manager, who can manage other roles in the organisation. A manager can not read or write data by default. This role should be appointed separately.

The User Management interface gives you an overview of all users in your organisation. As manager you can distribute the roles to all users within the organisation. This is done by clicking the ‘+’ next to the user and choose the roles you want to assign tot the user. Click “Save” to save the changes. If you are Manager of multiple organisations you can switch between organisations by using the selection menu next to your username.


A manager role is required to access the User Management interface. If you wish to obtain one for your organisation, please contact the application manager within your organisation or our Servicedesk at servicedesk@nelen-schuurmans.nl.

Adding a new user

You can add a new user by clicking the “NEW USER” icon in the upper right corner. This will lead you to the screen to add a new user.

The interface for adding a user.

Fig. 6 The interface for adding a user.

By default the new user is granted a ‘Viewer’ role. At least one role is required when inviting a new user. Press the ‘Save’ button to finish the invitation process, which results in an invitation email sent to the (new) user. An existing user can use the invitation link to accept the invitation. A new user can create an account by using the Signing up guide. When accepted, the user will appear in the User Management overview.


  • The invitation email might end up in your spam folder.

  • Deselecting all roles will remove the user from the organisation, but will not delete the account of the user.

  • You cannot remove your own manager role.


Within 3Di the data governance structure is set up per organisation. Users within the same organisation can see all models that are build under their organisation. Sharing models with external users is also possible. The two options are:

  • External users get access to the 3Di subscription of the organisation. By handing out Viewer and Simulation runner roles, the user can access and run the models.

  • Allow External users Viewer priveleges. This enables them to download the 3Di Models, so they can use their own subscription of their organisation to run simulations.

Personal API Key

When you login via your browser, your browser receives a session cookie. All subsequent requests to the API are authenticated with that session cookie.

Authenticating to the REST API outside of a browser is done by attaching a Personal API Key to every request. You can attach a Personal API Key to a request by using HTTP Basic Authentication with password = {your api key}. The username needs to be fixed to __key__ (with double underscores on both sides of the word “key”).

Almost all applications or script languages support HTTP Basic Authentication.

Generate a Personal API key at https://management.3di.live/personal_api_keys. It is considered best practise to generate one Personal API Key per application or script, so that you can selectively revoke keys in case they are compromised.