Question

Extrude from surface creates 3D objects with both in and out normals which are overlapping


Badge +1

Hello,

I am new to FME, and I am trying to understand a script made by someone before me. The major issue I have right now, is that the result from an extrusion (originally from shp files) is creating objects with several faces, for both in and out normals :

 

 

It looks like this :

The process leading me to this looks like this :

Of course, I would like to get rid of the inner faces, any ideas on how to do this ?

Thanks in advance


4 replies

Userlevel 2
Badge +17

Hi @mickael,

The format you are writing to is likely converting the extrusion solids to surfaces, and including both sides of the surface when doing so.

If you convert the solid within the workspace, you can control how the surface is written.

You can convert the extrusion solid to a surface using the GeometryCoercer, then extract only the outside (front) surface using a SurfaceSplitter:

I am including a sample workspace to illustrate:

outsidefaces.fmw

Badge +1

Hi @mickael,

The format you are writing to is likely converting the extrusion solids to surfaces, and including both sides of the surface when doing so.

If you convert the solid within the workspace, you can control how the surface is written.

You can convert the extrusion solid to a surface using the GeometryCoercer, then extract only the outside (front) surface using a SurfaceSplitter:

I am including a sample workspace to illustrate:

outsidefaces.fmw

Hi Dave,

 

I still have the same issue, but actually it only seems to happen when the SketchUp writer has the "Move to local coordinate system" parameter to "No".

 

I tried several projections, but the only way to get a proper .skp file is to set a local coord. system, which is not what I need.

 

 

Userlevel 2
Badge +17
Hi Dave,

 

I still have the same issue, but actually it only seems to happen when the SketchUp writer has the "Move to local coordinate system" parameter to "No".

 

I tried several projections, but the only way to get a proper .skp file is to set a local coord. system, which is not what I need.

 

 

Hi @mickael,

 

Sketchup uses 32 bit coordinates, so you will get a significant loss of precision if you write using most coordinate systems.

 

A local coordinate system ensures that the coordinate values are small enough to retain precision in 32 bits. FME will store the origin of the coordinate system as the file geolocation, so your data will still retain its position in the world.

 

Badge +1

Hi @mickael,

The format you are writing to is likely converting the extrusion solids to surfaces, and including both sides of the surface when doing so.

If you convert the solid within the workspace, you can control how the surface is written.

You can convert the extrusion solid to a surface using the GeometryCoercer, then extract only the outside (front) surface using a SurfaceSplitter:

I am including a sample workspace to illustrate:

outsidefaces.fmw

It is working with local coordinates indeed, even with several layers. Thanks for explanation !

 

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