Bug/ Feature Request? Section through Worksessions

We have adopted Worksessions heavily in our workflow to reduce the computing burden of complex vessel models. I have not yet spent sufficient time in the current WIP to fully test the updated Section tools, although I am excited about their potential impact on our workflow.

Currently, we use the Section command to generate slices through multiple models that are combined via Worksessions, which we then use to produce construction drawings. This workflow has proven to be fairly buggy.

Because we rely on AutoCAD for all downstream 2D drafting, it is critical that source layer information is preserved during export. When Maintain source layers is enabled and a Section is generated through worksessioned models, the resulting section geometry appears to enter a sort of limbo state: the geometry is assigned to layers that belong to the referenced worksession models rather than the active model.

We then use Make2D to bring that section geometry into the active model, still maintaining source layers. However, after doing so, the original Section geometry cannot be deleted because it does not exist in the active model. As a result, the section geometry accumulates until the file is closed.

Our current workarounds are:

  • Copy the Make2D output, undo past the Section command, and then paste the Make2D result back into the model, or
  • Ignore the accumulated Section geometry until we are finished, then close and reopen the file to clear it.

I am sure there are alternative workflows to achieve the same result, and I am open to suggestions, but this has been the most effective approach we have found so far.

From a functionality standpoint, this issue could be addressed in several ways, but a Make2D-style approach seems the cleanest. Ideally, when a Section is generated through worksessioned models, the resulting geometry would be duplicated into the active model, with source layers recreated locally—perhaps nested under a parent layer such as “Sections.”

I am very interested in hearing feedback or workflow recommendations.

Just a gentle bump.

Any feedback is appreciated. References around working with Worksessions are fairly limited. If my explanation is lacking, let me know and I can generate some sample files to demonstrate the issue.

If someone wants to tell me this is simply a stupid workflow and I should be doing it differently, I am all ears.

I haven’t been “professionally” modeling for very long and other than some drafting classes in high school (Class of 00) I’ve been almost entirely self-taught by gleaning what I can where I can. I am hyper aware that there must be better ways of doing much of what I do.

Thanks,
Ryan

Hi Ryan,

There are some improvements in this regard in the recent WIP, although not quite ready for prime time.

Here is a quick test using worksessions in the WIP (where more drastic improvements can be made).

Can you provide a small sample or full description of the desired workflow and object types? Assuming you are using blocks in the base file.

Note that using UseSourceLayer is going to be getting a few new bug reports shortly.. The undo stack is a big issue, granted the block output was just put into the workflow.

Hi Japhy,

Thank you for taking the time to respond.

We typically work with a combination of mostly closed solid polysurfaces and blocks, with occasional surfaces and curves (often for reference). Our day-to-day workflow uses the latest public Rhino release, so this was done in Rhino 8.

For this example, I used closed solid polysurfaces and open curves. I generated the sections using the following settings:

(ExtendSection=Yes AssignProperties=ByInputObject Output=CurvesOnly GroupObjectsBySectionPlane=Yes)

After isolating the generated curves, the curves originating from the attached model are effectively trapped—unable to be deleted or moved.

If the Section command is intended to remain active alongside Clipping Sections, it seems that the resulting geometry should be fully accessible. There may be better ways to implement this, but the first approach that comes to mind is to mimic the Make2D layer-creation behavior.

In my example, I used Make2D to generate accessible geometry. For demonstration purposes, I then replaced the section geometry with the Make2D output and renamed the parent layer from “Make2D” to “Sections” to illustrate the desired result. The final implementation could either:

  • Place only geometry derived from the attached model under a dedicated parent layer, or

  • Place the entire output under that parent layer.

I can see valid arguments for either approach. My primary goal is to have source-layer attributes tied to geometry that remains fully manipulable.

I will try to find some time to get the latest WIP installed and test the Clipping Section Drawings improvements, as they appear likely to provide a significantly better workflow once released. To be candid, Clipping Section Drawings was the primary reason I advocated internally for upgrading to Rhino 8. Unfortunately, its inability to maintain source layers—like the Section tool or Make2D—has made it unusable for our workflow.

These challenges are largely driven by the fact that we continue to use AutoCAD for our 2D construction drawings and submittals. That decision involves broader considerations and is ultimately outside my scope of authority, but it does shape the constraints within which we are currently operating.

Base.3dm (357.7 KB)

Attach.3dm (238.0 KB)

Hi Ryan,

I’ve created this youTrack that’s related to your post. The RhinoWIP is going to be the place where we can make changes in this regard.

RH-93506 Worksession Layers in SectionDrawings

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Japhy,

Thank you for helping out. Attention to some of these issues that seem like small things in the grand scheme mean a lot to me. It is nice feeling like the users’ experience has some value to the developers.