For questions about the Deneb custom visual in Power BI. Deneb allows you to create Power BI visuals using the Vega-lite (default) or Vega language. For code questions, include [vega-lite] or [vega] tags on your question.
What is Deneb?
Microsoft Power BI is a data visualization tool. "Power BI comes with many out-of-the-box visuals that are available in the visualization pane of both Power BI Desktop and Power BI service. Many more certified Power BI visuals are available from the Microsoft AppSource."2
Deneb is one such certified custom visual on AppSource. You can download a sample Deneb Power BI file there. Additional documentation on Deneb can be found on GitHub.
Why Deneb?
The amount of customization of the out-of-the-box visuals in Power BI is limited. If you want to do more customization of fonts, colors, formatting, or marks than the visual allows, you have to write your own custom code. Writing custom visualizations for Power BI is hard. They are usually written in D3 using Visual Studio, which is beyond the ability of most data and business analysts.
Deneb solves this problem by allowing you to enter Vega-lite or Vega code from within the Power BI visual. Vega-lite is still code, but significantly more accessible than D3. You can take a sample from the Vega-lite Example Gallery and easily implement it in Power BI even without understanding how the code works! With minimal learning, you can tweak the samples and eventually write your own complex visualizations.
Vega visualizations are highly customizable and interactive, and Deneb allows full integration and cross-filtering with other Power BI visuals. Prior to Deneb, it was difficult to create flashy infographics and high quality visuals in Power BI, especially compared with other tools such as Tableau. With Deneb, Power BI developers can now create beautiful visualizations too.
Finally, Vega is versatile. Vega code can be used not only in Power BI, but also in websites from JavaScript and in Python using Altair. You can develop one custom Vega visual and then use it many different places. Python and R visuals can be used in Power BI, but they are rendered as static images and do not allow the interaction and cross-filtering that Deneb allows. R and Python have huge problems with library versions in Power BI, while Deneb has the Vega libraries self-contained.
