Nop schrieb:
Hi!
I am very much interested in your work as I used srtm2osm, which is no longer working, and now I am looking for alternate techniques.
Christian Gawron schrieb:
Nop schrieb:
Sounds interesting. Does it also distinguish minor and major elevation lines? Currently the types are still hard-coded as follows: multiples of 200m: 0x22 multiples of 50m: 0x21 0x20 for all others This should of course be configurable (as well as a "feet" mode).
Should not be too difficult to make this configurable and also turn off the elevation texts for each level. No need to label each 10m-line.
Maybe I should use the styling engine here - I will have a look at it.
What determines the area in which the contour lines are calculated? The bounding box of the tile.
So each map tile must have a bounding box? What happens if there is none? Currently I am not generating them, but that's no problem. AFAIK the mapper generates a bounding box, but this may be too large.
Is there a way to avoid an overload with contours e.g. when processing the whole of Germany inclduing very flat country as well as the the alps? You may split the map and use diffeent settings for each tile.
This is still a problem. When creating a map of Germany, I have 440 tiles, but I cannot tell in advance which of them are too mountaineous too show with all altitude lines. Even if nothing crashes, if you show 10m lines for the whole of the alps, the map size will explode and the map consists mostly of altitude lines.
In the past, I have handled it by first creating the contour line .osm with srtm2osm and 10m lines. When the size of the output .osm was too large, I doubled the base distance to 20m lines and tried again, until the output size was within limits. Can you think of a way to integrate an upper limit for elevation lines and a try-and-error fitting against this limit to your calculations? Or even better, is there a way to predict the outcome without doing all calculations first?
I could add a feature which looks at the difference between minimum and maximum height in a tile and chose the interval based on this. Best wishes Christian