This is a style to visualize the presence of simple roof tags on certain types of buildings. It helps mapping buildings for Simple 3D visualization from aerial views.

Please add ideas for further improvement at the bottom of this page.

meta   
{
        title: "Simple roof tags";
        author: "heilbron"; 
        version: "1.14_2021-06-21"; 
        description: "Visualize the presence of some simple roof tags (shape & colour)";
        /* link: "http://josm.openstreetmap.de/wiki/Styles/SimpleRoofTags"; */
        watch-modified: true;
}
        
area[building]
{
        z-index: 1;
        fill-opacity: 0.03; /* let the background, i.e. the roof, be recognizable */
}

area[building]["roof:colour"]
{
        z-index: 1;
        opacity: 0.9;
        color: (tag("roof:colour")); /* if a color is set, use it to color the outline ... */
}

area[building]["roof:colour"=red]
{
        z-index: 1;
        color: #A54040; /* ... but make red (#FF0000) a mixture of  brown and red */
        opacity: 0.7;   /* less intrusive */
}

area[building]["roof:colour"=lightgrey]
{
        color: #C8C8C8; /* ... but make lightgrey (#D3D3D3) a little darker*/
}

area[building]["roof:colour"=grey]
{
        color: #A0A0A0; /* ... but make grey (#BEBEBE) a little darker*/
}

area[building]["roof:colour"=darkgrey]
{
        color: #505050; /* ... but make darkgrey (#A9A9A9) quite darker*/
}

area[building]["roof:colour"=brown]
{
        color: #802020; /* ... but make brown (#A52A2A) darker*/
}

area[building][!"roof:colour"]
{
        z-index: 1;
        color: #101010; /* no roof colour => make the outline almost black */
}


area|z17-[building][!"roof:shape"] /* no roof shape set? => dash the outline */
{
        z-index: 1;
        width: 4;
        dashes: 3,3;
        icon-image: url('help.png');
        shield-image: url("fills/grass.png");
}

area|z17-[building=~/garage.*/] /* ignore roof tags for garages, i.e. make them all look the same */
{
        z-index: 0;
        width: 2;
        dashes: 8,1;
        color: #282828;
        shield-color: blue
        shield-color: #0000FF;
        shield-opacity: 0.5;
        shield-frame-color: black;
        shield-frame-width:2;
        shield-casing-color: white;
        shield-casing-width: 2;
        shield-text: (tag("roof:colour"));
        /* shield-image:url('fills/grass.png'); */
        shield-shape: rounded;
}

area[building]["roof:shape"]
{
        z-index: 1;
        width: 5;
}

Styles_SimpleRoofTags-style.mapcss, Styles_SimpleRoofTags.zip

Ideas for improvements:

• Visualize the roof:orientation tag, i.e. using an icon.
• Make all visualized roof colours look a little darker (not just the ones adressed by the exceptions)
• Visualize also information that can be gathered by ground survey, i.e. roof:levels.