Drawing lines in modelsompace within an active Sections viewspace

With “project” on, Rhino places drawn lines on a plane at zero on the axis perpendicular to an ortho view. If an active section doesn’t encompass that coordinate, the lines are not displayed once drawn.

When an ortho Viewport or Detail has an active section and is aligned to it, and the sectionned volume doesn’t encompass the zero position on the axis perendicular to the view, can Rhino be set to project the lines drawn on a consistent plane within the section?

One way would be to create and activate a different cplane for every section, each with its origin within that section. I"m hoping for something simpler.

Hi @djhg,

I am not sure if I understand your request. If you need to draw lines in the section plane, you can do it just by activating the plane and aligning the view. This way you will be setting automatically a C plane aligned to the section and every line will be drawn on that C plane.


Thanks Alfonso, this is great. I thought there was a way.I haven’t consistently experienced it because I usually activate a section in a view which is already aligned (front, right, etc.) as an elevation. Even if its already aligned that way I guess it has to be “Vaaligned” to set the cplane.

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The above is only a partial discussion. I have been wanting to draw in a detail set to display a live VaSection. If the section is aligned to the view, a line can be drawn, but it’s not always possible to create, display, snap to, and edit control points in this set up; nor select lines. is this a bug?
Also, "the “Change Space” command brings objects from layout space onto 0 on the view’s z axis. I think it should be – and is expected to be – onto the section plane where the other drawing is occuring.

Hi @djhg,

Please, could you send me an example where it is possible to reproduce this bug?

Which “other drawing” do you mean?

I will see if the error is present in a file I create to send.

I am using “drawing” as a verb here. Drawing on the section plane.


Ok, I see what you mean and yes, I agree, in my opinion the geometry should be created in the construction plane if it is aligned with the view. However, the “Change Space” command is a Rhino feature (I could reproduce it without using any VisualARQ command), so I think it is something McNeel should fix.

Ok thanks. (I know nothing about these things, but it seems to me like Rhino’s programming routine would have to communicate with Va’s Section setting to accomplish this.)

In this case, what VisualARQ is doing is placing the Rhino’s construction plane aligned to the view, but you could have made that manually (VisualARQ just does this faster). I placed the Cplan manually without using VisualARQ and used the “Change Space” command and the result is the same: the geometry is not created in the construction plane. That is why I arrived to the conclusion that it is a Rhino issue as the problem occurs no matter if you are using VisualARQ or not.

+1 for making ChangeSpace using the viewport’s cplane, if there is one parallel to the view.
Definitely a McNeel topic.

There’s another problem related to this. Elsewhere on the forum I’ve mentioned that VaView modes revert to wireframe between closing and reopening a project. When this happens, the section must be reset to the viewport to enable drawing in the detail view on the section plane. Inevitably this changes the scale of the view and the detail’s zoom and placement must be completely reset. It’s quite problematic and time consuming. Furthermore, the fix mentioned on the post about the va view mode not persisting - to include a vaobject in the project - doesn’t always correct the problem. Hidden and Conceptual View modes deactivate between sessions

Today I’m finding that if I snap to objects in a detail view to which a section view has been set, the line indeed is drawn on the section plane (I can see it and select it in a model space perspective viewport), but I can’t select it or even see it in the detail window. If I draw a line without snapping to anything, that line is visible, selectable in the detail window, and also visible on the section plane.

Hi @djhg,

I don’t see the relation between having a different display mode and having to reset the viewport. You can just change the display mode beack to the one you need.

How are you reproducing this issue? I am doing it like this and it looks like it works fine:


Imagine a project with three layouts (there could be more) each of which contains 10 detail views. Each detail view consists of a hidden view mode detail (to get proper section fill display and clean lines) overlaid on a conceptual view mode (which displays transparent hatches in the model to fade textures and depict depth .) That’s 60 view mode changes. Imagine opening a project to print the drawings, the expectation for which among colleagues in a design office is to open the project and ctrl-P. But instead it’s going to take at least 15 minutes every time the project is open. If many of those details have vasections cut each action is going to take a lot more time due to lag, so it could easily be half an hour or much more.

And if you want to make a small modification (which is frequently the reason for opening a project to make new prints) by drawing lines in a detail view which display in any of these details, it often won’t do so unless the view is unlocked and the Va section is reset in the detail view, which changes the scale display and requires rezooming to get the correct scale again and panning and moving the detail to match the paired detail view.

A workaround to this may be to draw any lines in wireframe view mode detail, as that seems reliable so far, but maintaining section plane drawing in a detail view with a Va View mode active is unreliable for me.

I will send a project. The linework on the section planes is visible in the perspective views. Eventually I gave up drawing in the detail views and did it in the viewports, in wireframe, not in a Va view mode.

“If you need to draw lines in the section plane, you can do it just by activating the plane and aligning the view.” I believe Iherad from one of you at Va that it was the third “hose” icon (which “Sets” the section view as opposed to merely aligning it to the section or using the toggle control) which was required to activate section plane drawing. I have found this to be the case.

Hi @djhg,

I understand why it is annoying having to change the display mode of every detail view. What I don’t understand is why you need to reset VA sections changing the scale display. Are you not only missing the display mode but also VisualARQ sections are “deactivating” when opening a file?

I can’t draw on sections after a project has been closed and reopened until this button (active in the previously saved project) is clicked again.
This changes the scale of the detail view.
I will upload the project mementarily. The Layout in question is labeled thus:
Section Views Don’t Allow Drawing On Section Plane, if they do the lines are unselectable,and points generated with divide command don’t all displauy and none are selectable, all this unless “section Set” button is pressed, which Changes Scale. Detail WIndows on “Render” layer have changed from Conceptual View MOde to Wireframe
Let’s focus on troubleshooting this in Detail vieiws. THere are fewer issues in the Viewports. I am also sending the custom conceptual view mode from which the details all revert to wireframe on reopening a project.