Skip to main content
  • EN
Hi All,

 

 

I'm working with 3D solids (buildings) and sometimes they are made up of surfaces from which the orientation (order of the vertices) is not the way I would expect them to be. This causes that for some of the surface I'm looking at the 'inner' side in stead of the 'outern' side when visualising them.

 

 

Is there a good approach to 

 

1) detect these "wrongly oriented" surfaces

 

2) correct these "wrongly oriented" surfaces

 

?

 

 

(The SurfaceReverser can turn all orders of all the vertices for solids, (making inside outside and vice versa) but that is not what I'm looking for)

 

 

Thanks
Hi Bruno, 

 

 

Have you tried the Orientor?

 

 

Owen
Orientor eand orientationextractor show orientation, wich gives u direction of surfacenormal indirectly.

 

It can't tell u wether its pointing inside a solid or to the outside (afaik)

 

 

 

Hi Bruno,

 

 

This is not a straight answer to your question.

 

If the buildings are "pillars", you can re-create solids based on their foot prints - i.e. polygons projected on the horizontal plane, using 2DForcer, Extruder etc.. If you need to decompose the resultant solids into surfaces again, GeometryCoercer (Geometry Type: fme_comoposite_surface) and Deaggregator (Split Composites: Yes) can be used to do that.

 

 

Takashi
Thanks for the suggestions.

 

 

Actually, the OrientationExtractor was the one I needed. Because according to OGC, for an exterior surface, the vertices needs to be oriented counterclockwise (right hand rule).

 

 

This article also helped me understanding the solids and the surfaces.

 

(bottom of page 8 - orientation of surfaces)

 

 

https://www.google.be/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAA&url=http%3A%2F%2Frepository.tudelft.nl%2Fassets%2Fuuid%3Aa9ef005f-7c1f-4ca3-9194-a53a8c652bf2%2F299716.pdf&ei=EJjoU_7pJ8SX0QXNlYEQ&usg=AFQjCNEfRcH_lzv_13vjlNcmMoDzfvzzVA

 

 

ah, so it does.

 

 

Good to know

Hi bruno_de_lat !

 

The like is no longer active, can you fix this?

 

 

Best/

 

Johan

Hi bruno_de_lat !

 

The like is no longer active, can you fix this?

 

 

Best/

 

Johan
Hi @northswejohan , seems you have the same problem since you are requesting the link to the documentation. Have you manage to solve your problem? I'm traying to detect wrong orietation in building/bridges walls.

 

Reply


Community Stats

30,470
Posts
115,705
Replies
38,288
Members
Terms & ConditionsCookie settings
A product of
Safe Software respectfully acknowledges that we live, learn and work on the traditional and unceded territories of the Kwantlen, Katzie, and Semiahmoo First Nations.