# Shadow Accrual Maps: Efficient Accumulation of City-Scale Shadows Over Time

arXiv: https://arxiv.org/abs/1907.04435 · HTML: https://mlsanity.com/paper/1907.04435/

## Key facts

- Cited by 6 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 9 Jul 2019.

## Built on by (most cited first, 6 of 6)

- [CitySurfaces: City-Scale Semantic Segmentation of Sidewalk Materials](https://mlsanity.com/paper/2201.02260/) (2022)
- [Sidewalk Measurements from Satellite Images: Preliminary Findings](https://mlsanity.com/paper/2112.06120/) (2021)
- [Urban Rhapsody: Large-scale exploration of urban soundscapes](https://mlsanity.com/paper/2205.13064/) (2022)
- [Urbanite: A Dataflow-Based Framework for Human-AI Interactive Alignment in Urban Visual Analytics](https://mlsanity.com/paper/2508.07390/) (2025)
- [Transportation Scenario Planning with Graph Neural Networks](https://mlsanity.com/paper/2110.13202/) (2021)
- [Deep Umbra: A Generative Approach for Sunlight Access Computation in Urban Spaces](https://mlsanity.com/paper/2402.17169/) (2024)

## Abstract (arXiv)

Large scale shadows from buildings in a city play an important role in determining the environmental quality of public spaces. They can be both beneficial, such as for pedestrians during summer, and detrimental, by impacting vegetation and by blocking direct sunlight. Determining the effects of shadows requires the accumulation of shadows over time across different periods in a year. In this paper, we propose a simple yet efficient class of approach that uses the properties of sun movement to track the changing position of shadows within a fixed time interval. We use this approach to extend two commonly used shadowing techniques, shadow maps and ray tracing, and demonstrate the efficiency of our approach. Our technique is used to develop an interactive visual analysis system, Shadow Profiler, targeted at city planners and architects that allows them to test the impact of shadows for different development scenarios. We validate the usefulness of this system through case studies set in Manhattan, a dense borough of New York City.