Rasterization

Polygon to grid raster

The rasterization model is a part of the Simulation Core, that is tasked with converting attributes and polygons from features of various layers into raster values.

• Most geospatial data is represented as polygons, such as the 2D layout of a building or woodlands. When you select Update, the Tygron Platform automatically begins rasterizing this data into the required raster grid at the resolution you specify.

• The internal Rasterizer is specifically designed for small grid cells (<1m), leveraging the power of Cloud Computing to enable multiple cores to work on the conversions simultaneously. In many cases, you may have multiple simulations running, which are also processed in parallel in real-time.

• Internal caching further optimizes this process, ensuring that when you hit recalculate, the rasterization occurs even more quickly.

Layers

The layer rasterization sequence of the polygon features is:

1. Net Lines
2. Addresses
3. Buildings
4. Terrains
5. Areas
6. Neighborhoods

Methods

Converting polygons to grid cells can be done in different ways. A common approach is by checking the intersection between the polygon outline and the cell. As displayed below:

Outline rasterization method

However this will create a small overshoot resulting in larger cell area than the original polygon. To correct for this one could also rasterize based on the center point. As displayed below:

Center rasterization method

While more accurate, this method may fail for objects smaller than the grid cell area. If the cell center point misses a small object, it won't be rasterized and remains as traversable space in the simulation.

To compensate for this situation the default option is combined center + outline. This method uses center-point rasterization for most objects and outline rasterization for small ones to ensure coverage.

Via the editor Calculation panel the rasterization method can be selected.

• Combined Center for large and Outline for small polygons (default).
• Outline Overshoot results in more cells than polygon area.
• Center Fastest but missing small polygons.

Select rasterization method in calculation panel

Notes

• Before 2025, the Tygron Platform used the "Outline" rasterization. Since then, the "Combined" rasterization has become the default.

See also

• Grid Overlay
• Rasterization (Average Overlay)
• Rasterization (Combo Overlay)
• Rasterization (Distance Overlay)
• Rasterization (Sight Distance Overlay)

API Endpoints

• Api session event editor setting set rasterization