there had been a small discussion and some questions regarding 3D tagging on the german mailing list recently. For the ease of editing I suggested to use the great 3D preset by Kendzi (which is included in current JOSM version, you just have to activate it). However, there’s no (sufficient) list of building:material and roof:material values, yet. After talking with Kendzi we agreed that we should start a discussion and ask for other’s opinions.
First of all: I love the combo box for roof:shape and the little images so that one knows what the words mean. That’s why we should have something similar for materials, too. However, how should this be done? Should we use a image or a drawing?
When using a drawing it might be difficult to actually understand the exact meaning associated with it: Brick, granite, sandstone,… Yet, using images might lead to confusions: The image shows a special type of roof tile (e.g. a round one) but in reality it’s another subtype (e.g. a rectangular one). However, I’d still prefer the images (e.g. using some of those from the texture page) as they’re more meaningful.
The second and more important question is the list of values itself. On the one hand it should cover most houses out there, on the other hand it should be a compact list with just a few possible values.
That’s why I’m asking for suggestions for building and roof materials and for the level of details we should use for those lists.
In the end I’ll update the wiki accordingly, but wanted to hear some opinions first.