[MicroStation V8i SS3 VBA] Why the macro execution speed depends on the zoom in the drawing?

I suspect that the circle used to define your fence is being stroked to a different number of points based on it's size in the view.

Fence processing works on a set of convex clip planes, so when a fence is defined by curves and the fence has a view associated with it, it's stroked to a view based tolerance. Lots of clip planes means testing against the fence takes more time.

If you want to use a fence for this, try creating it from a N-sided polygon (choose a reasonable number for N that doesn't take to long to process and is accurate enough for your use case). The approach Jan outlines is perfectly reasonable as well.

HTH

-B

I did the test and turned the circle into a polygon, the problem persisted

code that creates a fence from a polygon

Sub FencePolygon(origin As Point3d, radius As Double)


Dim nVertices As Long
nVertices = 1000
Dim vertices() As Point3d
ReDim vertices(0 To nVertices - 1)
Dim n As Long
Dim angle As Double
For n = 0 To nVertices - 1
  angle = 2 * Pi * n / nVertices
  vertices(n).X = origin.X + radius * Cos(angle)
  vertices(n).Y = origin.Y + radius * Sin(angle)
  vertices(n).Z = 0#
Next n

Const View1 As Long = 1
Dim oFence As Fence
Set oFence = ActiveDesignFile.Fence
oFence.DefineFromModelPoints View1, vertices

End Sub

I wrote a demo as if someone wanted to test. I do not understand the solution by Jan. :_(

demo zoom problem.dgndemo.mvba

Mateusz Czajkowski said:

code that creates a fence from a polygon

I do not know how a circle is "polygonized", but to use 1000 vertices sounds like an overkill to me.

Did you try something like 50 or 100 to measure whether there is any difference?

Mateusz Czajkowski said:

I do not understand the solution by Jan

What exactly you do not understand?

Scanning element is basic MicroStation VBA operation, documented well by many examples both in MicroStation VBA help and I guess also in mvba files delivered with MicroStation.

To use ElementScanCriteria with IncludeOnlyWithinRange is probably not demonstrated on exampe, but it's not different from other types of scanning, plus it's possible to find older discussions about this method.

Or is the problem in the second step?

With regards,

  Jan

Mateusz Czajkowski said:

code that creates a fence from a polygon

I do not know how a circle is "polygonized", but to use 1000 vertices sounds like an overkill to me.

Did you try something like 50 or 100 to measure whether there is any difference?

Mateusz Czajkowski said:

I do not understand the solution by Jan

What exactly you do not understand?

Scanning element is basic MicroStation VBA operation, documented well by many examples both in MicroStation VBA help and I guess also in mvba files delivered with MicroStation.

To use ElementScanCriteria with IncludeOnlyWithinRange is probably not demonstrated on exampe, but it's not different from other types of scanning, plus it's possible to find older discussions about this method.

Or is the problem in the second step?

With regards,

  Jan