BPOLY Command fails

[grahamcook]

Hi

We are developing an AutoCAD Plugin that Silhouette's the skyline from the face of any given window.  It's a complex, multi-stage process and one of the stages is to create a boundary from any given point, with the input being several thousand lines draw on one flat projection plane.  We are using the .NET method TraceBoundary for this that does the same thing as the BPOLY command hence my post to this forum.

It's working 80% of the time but sometimes fails to create the boundary and i don't know why.  I've created a very simple example file from one of the failures and stripped it down to just 5 lines.  As far as i can tell the lines are flat and on the same plane but the BPOLY command is not able to determine a boundary.  If anyone knows why or can suggest a command that will fix the issue (similar to FLATTEN)?

Thanks.

Regards

Graham Cook

[Alfred.NESWADBA · Accepted solution]

Hi,

my guess: it's the size of the objects, that is close to impossible working with that small objects.

Scale your objects before running _BPOLY and scale the result back to your needs (scaling by factor 1000 works for me).

As you see the distance is really small and comparing start- and endpoint of the diagolnal line needs more decimal places than shown (by default).

- alfred -

[grahamcook]

Thank you Alfred! Yes, that's it.  The models are in meters and by the time we have projected a 150 degree view of the entire model onto a 1m wide view plane we are getting some very small geometry.  Scaling up 1000 sorts it.

Regards

Graham Cook