Add a missing "=" to create a valid SVG for ellipses.
I accidentally stumbled upon a way to actually get an ellipse in SVG by
tilting a cylinder. If I tilt the cylinder via the `ObjectPlacement` of
the `IfcProduct` I get an ellipse. If I set the `ExtrudedDirection` of
the `IfcExtrudedAreasolid`, however, I get a sampled path.
Use <circle> and <ellipse> to create a valid SVG for these geometries.
Limit to only the *first* edge. I am not sure whether there are
scenarios with multiple edges like this:
1. One or more straight line pieces or arc segments
2. A full closed circle
3. More straight lines or arc segments
If there is, we are keeping the original behavior here.
For the scenario where we a building storey and it has an elevation:
Instead taking the cross section of every product 1 meter above it's
lowest, take the cross section at storey elevation + 1 meter.
`if(bounding_width)` evaluates to true as long as `bounding_width` is
non-zero (including negative values). Since `bounding_width` and
`bounding_height` are default initialized to -1.0, we were erroneously
setting a bounding rectangle of (-1.0, -1.0) here. This means the SVG
output has been broken/malformed if we didn't specify --bounds.
* ifcgeom: Add placement_rel_to for convert()
Change geometry conversion in `convert()` for `ObjectPlacement` such
that we can stop the `PlacementRelTo()` recursion when we hit an
`ObjectPlacement` that places a certain type, e.g. a `IfcSite'.
Introduce a new IteratorSetting `SITE_LOCAL_PLACEMENT` which will be
exposed in `IfcConvert`.
* IfcConvert: Add --site-local-placement
Some IFC authoring tools may put the global origo at a large distance
away from the actual building geometry. Also, the global X- and Y-axes
may be at arbitrary angles with natural building axes. Using
--center-model or --model-offset may place the converted geometry closer
to origo, but will still use the global IFC definition of axis
directions. Also, in a scenario with multiple IFC files for one
construction site, using --center-model on each of them would not
generate consistent geometry across OBJ or DAE files.
Solve this by introducing --site-local-placement which will disregard
the ObjectPlacement at the IfcSite level.
Thomas Krijnen