Vega is a visualization specification language that describes how to map your source data to your viewing area. By creating a JSON Vega specification structure, you define the data and the transformations to apply to the data to produce meaningful visualizations. The specification includes the geometric shape that represents your data, scaling properties that map the data to the visualization area, and graphical rendering properties.
OmniSci uses Vega for backend rendering. Using the OmniSci Connector API, the client sends the Vega JSON to the backend, which renders the visualization and returns a PNG image for display. See the MapD Charting Examples for backend rendering examples.
The topics in this guide define and describe the OmniSci implementation of Vega, and provide examples you can use as a basis for your own visualizations:
- Tutorials - Introduces you to Vega specification patterns so you can start creating visualizations quickly and easily. Each tutorial has example code that demonstrates a particular feature or pattern. Tutorials start with basic Vega concepts and an introduction to the API for communication with the backend. Other tutorials provide more in-depth information about specific Vega implementations.
- Reference - Describes the OmniSci implementation of Vega specification syntax and associated rules. Also includes links to Vega standards and related specifications.
- Code Migration - If you are upgrading OmniSci to Release 5.2 or higher, you need to migrate any code that renders polygons in cached mode to dynamic poly rendering.
- Try Vega - Try the OmniSci Vega engine and work with various examples. See your changes to Vega code in real time.