On 30/03/19 05:16, Christoph Hormann wrote:
On Friday 29 March 2019, Martin Koppenhoefer wrote:
* you should be aware that you can't uniquely define the shape of a
two dimensional surface in three dimensions exclusively through the
shape of its outline. You can do that in 2d (provided what you
have has a defined outline) but not in 3d. That is simple
mathematics. So you'd have to document what assumptions you make
regarding the shape of the surface, otherwise the meaning of your
proposal would be ill-defined.
the general assumption for stairs is that all steps have the same
height and same "depth".
That would not be a very sensible assumption since that would be
impossible for any stairs where the upper and lower end are not
equidistant across their whole length because then not all steps can
have a constant depth.
In this case the stairs can have a different number of steps from on side to
the other.
This keeps the same 'rise' and 'run' (technical step terms for 'depth' and
'height') the same for all the steps.
Making the step rise and run is important for safety .. it is also cheaper!
Think you will find most modern steps follow this method of construction, at
least the ones I have come across do.
What of the case where the stair rise/run is not constant?
Document the rise/run on each lateral ... assuming that the change across the
step facer is consistent.
If it is inconsistent, separate the areas at the line/s of inconsistency.
_______________________________________________
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging
