As you would have seen from the referenced GIS SE question, there doesn't appear to be much in the way of viewshed stand-alone packages at least in the Open Source market beyond SAGA and GRASS GIS. Apart from writing a wrapper around the code for these algorthims you may end up implementing viewshed yourself unfortunately. (Though I would love to be corrected on this.)

If you read the documentation for the GRASS r.viewshed function it provides a broad description of the algorithm and a reference to the following paper which thoroughly discusses one viewshed algorithm:

Computing Visibility on Terrains in External Memory. Herman Haverkort, Laura Toma and Yi Zhuang. In the Proceedings of the 9th Workshop on Algorithm Engineering and Experiments / Workshop on Analytic Algorithms and Combinatorics (ALENEX/ANALCO 2007).

Alternately the Wikipedia article on Viewshed provides references:

Wu, H., Pan, M., Yao, L., & Luo, B. (2007). A Partition-based Serial Algorithm for Generating Viewshed on Massive DEMs. International Journal of Geographical Information Science, 21(9), 955-964.

As you would have seen from the referenced GIS SE question, there doesn't appear to be much in the way of viewshed stand-alone packages at least in the Open Source market beyond SAGA and GRASS GIS. Apart from writing a wrapper around the code for these algorthims you may end up implementing viewshed yourself unfortunately. (Though I would love to be corrected on this.)

If you read the documentation for the GRASS r.viewshed function it provides a broad description of the algorithm and a reference to the following paper which thoroughly discusses one viewshed algorithm:

Computing Visibility on Terrains in External Memory. Herman Haverkort, Laura Toma and Yi Zhuang. In the Proceedings of the 9th Workshop on Algorithm Engineering and Experiments / Workshop on Analytic Algorithms and Combinatorics (ALENEX/ANALCO 2007).

Alternately the Wikipedia article on Viewshed provides references:

Wu, H., Pan, M., Yao, L., & Luo, B. (2007). A Partition-based Serial Algorithm for Generating Viewshed on Massive DEMs. International Journal of Geographical Information Science, 21(9), 955-964.

As you would have seen from the referenced GIS SE question, there doesn't appear to be much in the way of viewshed stand-alone packages at least in the Open Source market beyond SAGA and GRASS GIS. Apart from writing a wrapper around the code for these algorthims you may end up implementing viewshed yourself unfortuantely. (Though I would love to be corrected on this.)

If you read the documentation for the GRASS r.viewshed function it provides a broad description of the algorithm and a reference to the following paper which thoroughly discusses one viewshed algorithm:

Computing Visibility on Terrains in External Memory. Herman Haverkort, Laura Toma and Yi Zhuang. In the Proceedings of the 9th Workshop on Algorithm Engineering and Experiments / Workshop on Analytic Algorithms and Combinatorics (ALENEX/ANALCO 2007).

Alternately the Wikipedia article onh Viewshed provides references to:

Wu, H., Pan, M., Yao, L., & Luo, B. (2007). A Partition-based Serial Algorithm for Generating Viewshed on Massive DEMs. International Journal of Geographical Information Science, 21(9), 955-964.

As you would have seen from the referenced GIS SE question, there doesn't appear to be much in the way of viewshed stand-alone packages at least in the Open Source market beyond SAGA and GRASS GIS. Apart from writing a wrapper around the code for these algorthims you may end up implementing viewshed yourself unfortunately. (Though I would love to be corrected on this.)

If you read the documentation for the GRASS r.viewshed function it provides a broad description of the algorithm and a reference to the following paper which thoroughly discusses one viewshed algorithm:

Computing Visibility on Terrains in External Memory. Herman Haverkort, Laura Toma and Yi Zhuang. In the Proceedings of the 9th Workshop on Algorithm Engineering and Experiments / Workshop on Analytic Algorithms and Combinatorics (ALENEX/ANALCO 2007).

Alternately the Wikipedia article on Viewshed provides references:

Wu, H., Pan, M., Yao, L., & Luo, B. (2007). A Partition-based Serial Algorithm for Generating Viewshed on Massive DEMs. International Journal of Geographical Information Science, 21(9), 955-964.