GetObjects bug? selecting surfaces when only Polysurface filter is active

Hi guys,

draw any single face surface in rhino and run this with python:

import rhinoscriptsyntax as rs

rs.GetObjects(“Select objects”, 16)

The selection filter is set to 16 which refers to Polysurfaces. Why is it still possible to select a single face surface?


Looking at __FiterHelper in it’s obvious that 16 will filter Breps thus not excluding Surfaces

If you use 2097152 as filter, it works as expected.


def __FilterHelper(filter):
    geometry_filter = Rhino.DocObjects.ObjectType.None
    if filter & 1:
        geometry_filter |= Rhino.DocObjects.ObjectType.Point
    if filter & 16384:
        geometry_filter |= Rhino.DocObjects.ObjectType.Grip
    if filter & 2:
        geometry_filter |= Rhino.DocObjects.ObjectType.PointSet
    if filter & 4:
        geometry_filter |= Rhino.DocObjects.ObjectType.Curve
    if filter & 8:
        geometry_filter |= Rhino.DocObjects.ObjectType.Surface
    if filter & 16:
        geometry_filter |= Rhino.DocObjects.ObjectType.Brep
    if filter & 32:
        geometry_filter |= Rhino.DocObjects.ObjectType.Mesh
    if filter & 512:
        geometry_filter |= Rhino.DocObjects.ObjectType.Annotation
    if filter & 256:
        geometry_filter |= Rhino.DocObjects.ObjectType.Light
    if filter & 4096:
        geometry_filter |= Rhino.DocObjects.ObjectType.InstanceReference
    if filter & 134217728:
        geometry_filter |= Rhino.DocObjects.ObjectType.Cage
    if filter & 65536:
        geometry_filter |= Rhino.DocObjects.ObjectType.Hatch
    if filter & 131072:
        geometry_filter |= Rhino.DocObjects.ObjectType.MorphControl
    if filter & 2097152:
        geometry_filter |= Rhino.DocObjects.ObjectType.PolysrfFilter
    if filter & 268435456:
        geometry_filter |= Rhino.DocObjects.ObjectType.Phantom
    if filter & 8192:
        geometry_filter |= Rhino.DocObjects.ObjectType.TextDot
    if filter & 32768:
        geometry_filter |= Rhino.DocObjects.ObjectType.Detail
    if filter & 536870912:
        geometry_filter |= Rhino.DocObjects.ObjectType.ClipPlane
    if filter & 1073741824:
        geometry_filter |= Rhino.DocObjects.ObjectType.Extrusion
    return geometry_filter

Hi Willem, thanks for helping out. Could you explain how you found out? Where do I find this __Filterhelper or

On my phone so no screenshots but:

On the line where rs.Get… is written, Click in the left margin of the textfield editor. You’ll see a red dot appear. That’s a breakpoint. If you now run the script it will halt at that line. In the upper bar arrow icon buttons appear that let you step skip etc… Through the code.

If you “step in” it will open the scriptfile rs.GetObject() is in. In the method a call to __FilerHelper() is made and if you keep stepping in the code you’ll get there .

Does this makes sense?

EDIT:. Found older post with images:

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Now that’s useful info. Thanks a lot, Willem!

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@pascal is this supposed to be like that or is it a bug?

Hi Siemen - the actual 16 filter is for a brep which does include single surface breps- as far as I know all of this is as expected, though I understand the possible confusion. Similarly 16 allows extrusion objects to be selected - you can also filter those explicitly - this was a more deliberate decision though, I believe, in not, where possible, differentiating breps from extrusions.


Then I suggest changing the info on the page I linked to above from
“16 Polysurface or multiple-face”
“16 Brep”

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