On 03.05.19 19:00, Christoph Hormann wrote: > That illustration does not show the original data so it does not tell > very much.
Here's the raw data if you'd like to examine it: http://tobias-knerr.de/upload/Step%20Polygon%203D%20Examples/ Please excuse the sloppy mapping, those are just intended as tests. > Like for example classic curved stairs: > https://www.alamy.com/stock-photo-one-of-the-curved-stone-staircases-at-picton-castle-near-haverfordwest-58935307.html Indeed. Winding/curved steps are a separate category from the straight steps this algorithm is designed to solve. As I said previously: On 11.04.19 23:28, Tobias Knerr wrote: > Note that the method I describe above does not even try to work for > winding steps (i.e. those which you don't ascend in a straight line). > But there are other algorithms that would work for those, and the two > classes of steps could potentially be distinguished with a tag. While you correctly point out several further limitations, I think it's important to keep in mind that this isn't an attempt to define a data model that works for everything. It's about finding a sweet spot that works for a sufficiently large class of steps to be worth it and is still relatively simple. As for that data model that works for (almost) everything, I believe that will have to be drawing a way across the edge of each step. Increasingly complex staircases could then be modelled accurately by simply adding more information (if the mapper is in the mood for micromapping): 1. Just draw a way. 2. Additionally draw a polygon around the steps. 3. Additionally draw a way along the edge of each step. Each level of detail would just add more data on top of what's already there, which I believe is a desirable property. Tobias _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
