Assigning material types

[berendsen]

Hello All,

I'm trying to automatically assign material types to a mesh according to the local land use pattern. So far I've found two ways:

1.) for an existing mesh, manually assign each element one material type

2.) assign the polygons, which are used to bound the auto-generation areas, a material type and then generate the mesh

1. is, especially on larger meshes, very error-prone and time-consuming. 2. is possible, if one can generate the mesh from polygons - which isn't always possible or feasible.

Is there a way to assign material types to an existing mesh using a polygon-shape?

Thanks for the help and have a good WE,

S. Berendsen

[Alan K. Zundel]

You can use an "Area property coverage"

1- create a new coverage and assign the type to be "Area Property"

2- define the material zones as polygons in the coverage

3- When you issue the "Map -> 2d Mesh" command specify that you want to use the Area Property as the material source. (I think you can also use this to just assign material types to an existing mesh as well.)

There is also a method to use a land use raster, but that has only been developed for the ADCIRC model so far. If you are interested in using a raster approach, we can talk some more.

[berendsen]

Thanks - works like a charm! It might be a good idea to include this work flow somewhere on the wiki or the demos ...

I think I'll have to decline wrt land use raster - we only have polygon-shape land use data. Except ... we have false colour airial images for the area. Is it possible to automatically classify land use according to the colour bands in a neighbourhood raster? <- somehow this sound more like a GIS exercise, though.

[Alan K. Zundel]

We are working on a method to use the colors in an image. It is a very GIS approach, but can still be useful.

We will add the area property coverage to the wiki.