About DE-9IM Visualizer

What is DE-9IM?

The Dimensionally Extended Nine-Intersection Model (DE-9IM) is a way to describe how two geometries (points, lines, polygons) relate in space. It looks at the intersections between each object's interior, boundary, and exterior, resulting in a 3×3 matrix.

Learn more on Wikipedia

Visualization and why it helps

Reading DE-9IM as raw codes like FF2F11212 can be confusing. This visualizer lets you drag and drop shapes on the canvas and directly see how the relation matrix changes. Each relation is also explained in plain English below its matrix.

Only unique pairs are shown, such as A×B instead of both A×B and B×A. Mathematically, A×B is the transpose of B×A, so showing both would repeat the same information.

Why this was made

This is a basic tool created for fun and learning. While exploring DE-9IM I wanted to find a visualizer, but since I couldn't, I decided to make this simple version myself.

Credits

This project was built with help from existing open-source libraries:

• React-Konva for drawing and dragging shapes.
• JSTS for geometry and relation logic. JSTS is a JavaScript port of the Java Topology Suite (JTS), the library behind many GIS tools.

GitHub

Source code: GitHub Repository

Feedback

You can reach me via my contact page.