openstreetmap road cross problem(JSOM/Mapnik )
Posted by 自由分享 on 10 October 2015 in Chinese (China) (中文(中国大陆)).To OSM engineer: I Usually use JSOM to modify OSM data.I don’t know the rule of Mapnik a tool to render OSM data。To my experience,Mapnik ,rendering road,will make road to area having to arc port。 When two roads cross,the road having high layer will cover the road having low layer.When two roads cross and they have equal layer,the rule of covering is:bridge covering road、road covering road link、the most important road covering the least important road. As wo see,the effect is very well,everyone(at least I) can understand the road through the map.However when roads cross and the secondary road have the high priority for Mapnik rendering(having high layer /being bridge e.g.),the intersection rendered by Mapnik is confusing(at least me).
举一例:
额,实在不会翻译。。。 绿色弯道(layer=2)和向上的红色道路(layer=1)交叉相连,绿色弯道虽然是道路连接线(次要道路),但layer值高,绿道几乎完全挡住了红色的主道。这种表现形式,给我一种沿红色道路向上走只能通过绿色弯道左拐的感觉。
上述情况主要出现在不同优先级道路交叉相连且两条道路夹角小于90度或更小时。 注:上述情况在JOSM中并无交叉警告,可以理解为OSM基金会认可这种做法。 改善这一状况我想有以下几种方法: 1.修改渲染器,改善上述情况的渲染效果。 2.指定方针,不提倡某些情况的道路交叉,同时修改JOSM,两条道路夹角较小时,道路优先级不同给出警告。 3.其他可行的方案 不管用什么方案,我想OSM基金会总要做点什么。