ExtractClippingSlices bug?

Hi there,

i’ve been using _ExtractClippingSlices command on a very simple object and wondered why it takes so long to compute. Turns out it sliced some hidden SubD test object with 200k faces and created the results also hidden. Once i’ve shown the hidden content of by doc i got a big surprise.I did not expect that hidden geometries are involved at all, is this supposed to happen ?

Also happens when using _ExtractClippingSections. (8.17.25023.14001, 2025-01-23)

thanks,
c.

I could not reproduce that here. If you have a sample file that has this behavior that would be helpful.

Hi @Gijs,

below is what i see, the hidden object in this example is a render mesh extracted from a SubD box. If this mesh is hidden and i run _ExtractClippingSlices, select the ClippingPlane object and press Enter, i get a section on the visible brep as expected. If i show the hidden mesh, i have a section for it too. Not sure if this is supposed to happen ?

ExtractClippingSlices

ExtractClippingSlices.3dm (505.4 KB)

_
c.

ah, I think I didn’t see this bug because I ran into another. Here clipping sections for SubD’s is broken…

RH-85941 Extract Clipping Sections / Slices extracts hidden

Hi @Gijs, i’ve noticed that too when i was trying to replicate the bug, it did not make a section for the (visible) SubD, so i extracted the render mesh where it worked when it was visible. But i’ve been surprised it made the section for the mesh when it was hidden. There is definitely something broken, eg. if i move the section objs in shaded mode, they dissappear and only the gumball indicates there is something selected:

ExtractClippingSlicesShaded

I can still see the section objects in other views which are not shaded. Can you repeat that as well ?

_
c.

that seems expected, you’re dragging it into clipped space. Happens in all Rhino versions afaik

Indeed, i’ve accidentally clipped the clipping section in the last video. Are you able to repeat that the section is made for the hidden mesh ?

_
c.

yes, that one I logged above (the subd issue is also logged)

1 Like

thanks for logging this.

_
c.