Section Lineweights - Successful Workflows and Existing Problems

Hi All,

After tripping on this for a week or so, I thought I’d check in with everyone else on this.

Does anyone have a successful and efficient workflow for setting lineweights to sectioned VA objects?

The two methods I know of don’t appear to be working at all and are the following:

VAobject Section Style → By Layer → By Rhino Layer Dialog

VA Section Style by Layer (Great!)

If you direct a VA object to set it’s section style by the layer the object sits on, the hatch pattern will work with some consistency, but section line weights will not.

Additonally, withing the R8 section style dialog, you can set the lineweight as a “Scale” or as a “Linetype”, which allows you to target a set of a user created linetype from the properties window.

This would be ideal, as it would mean standards across types would be more easily matched and there’d be less fumbling in VAObject menus trying to remember which object you need to modify. You can just go to your layers or to your linetypes and keep it all organized there.

VAObject Section Style → Custom

This allows you to directly set an objects section style via custom properties per object or object layer. More cumbersome to operate since you have to jump between objects to control them, but still workable (if it worked). For example, if I have a concrete slab and a concrete wall, and I want their section properties to match because they should both be recognizably the same material type, I’d rather do that from one location.

Here’s the catch: as far as I can tell, none of these methods work. I have been unable to successfully change the lineweight of a sectioned object (and then print that lineweight) by any method.

Am I missing something here, or is this feature simply not working?

Hi @Clayton_Muhleman the Rhino 8 Section styles dialog doesn’t have the property for a boundary print width. There’s a scale attribute and linetype thickness for the section boundary, that could be used for that, but it currently works for display only, and doesn’t apply to printing results. It’s a pity, but it makes kind of useless to assign the section styles of VisualARQ objects “By Layer”, which would be the most convenient and desired way, because you have no control of the boundary print width.

However, I think this has been improved in Rhino 8 SR14. (I have not tried it yet). Check this out: https://mcneel.myjetbrains.com/youtrack/issue/RH-80568

In the meantime, as you well know, in VisualARQ 3 we have integrated the Rhino section styles into our dialogs, and have added a Print Width attribute to have control of that missing attribute in Rhino8.
You can find it in the VisualARQ styles dialog:

And also in the Properties panel (Section Attributes):

Yes, custom section in VA seems to be the best way to do it. Unfortunately, every

Some print output troubleshooting. Here’s print preview in layout view, which is (except for the undesired green outline on the cabinetry) pretty much what we’re looking for.

Here’s what it looks like in the print dialog and what it plots as. The hatches pick up section boundaries, the cabinets display correctly, and the guide curves magically reappear.

Ideally print preview would be a “what you see is what you get” situation. Any idea how we can get control of these settings?

Hi @Clayton_Muhleman can you share a sample file to test this printing issues?

Hi @Clayton_Muhleman got your file thanks! It looks like VisualARQ is not taking into account the “show” status of the section boundary of the slab. I’ll let you know when we fix this.

Glad to hear you were able to replicate the bug!

Looks like I somehow deleted my response above, but to summarize:

It seems like VA has done everything that can be done, due to the parallel functions of the Rhino and VA section boundary capabilities. While VA’s section lineweight is working, the more efficient workflow would be to use layers, which depends on Rhino sections.

I’ll start talking with the Rhino guys to see if we can get this fixed, @fsalla, do you have any insights on when we can expect it to get addressed directly in R8?

Thanks again for your help.

Hi @Clayton_Muhleman I’m also awaiting for McNeel to add a “Print Width” attribute in their section styles. You can follow this request here: https://mcneel.myjetbrains.com/youtrack/issue/RH-81795/Section-Style-Boundary-Not-Using-Widths

Exciting news, we’ve got a new test release that makes the R8 section boundary lineweights work for printed drawings. However it doesn’t seem to work with VA display modes.

The layout on the top is set to Hidden and the bottom is set to Wireframe.

This is with Rhino 8 SR15 2025-1-7 (Rhino 8, 8.15.25007.17001

We’re getting close! Any idea what might be going on here?

Thanks again

Hi @Clayton_Muhleman It’s not working on my side… and I think McNeel has not implemented this feature yet, unfortunately.

I’m trying this with Rhino (8.15.25007.13001, 2025-01-07)… using different display modes (Wireframe, Technical, Shaded…) and printing to raster or vector output. No success!

In my test, I have two curves, the straight one has a print width of “hairline”, the other one a Print Width of 1mm, (just to compare).

Then I have a cone, that has as section style a boundary with a “Width Scale” set to 1, and the linetype has a Width of 1 millimeter.

I’m sectioning the cone with a Clipping plane. So VisualARQ is not being involved at all here.

There is no way to make the sectioned boundary of the cone be printed with the same width (1mm) as the second curve.


Print Width Test.3dm (4.6 MB)

Are you sure? I’d like to see it.

Probably because VisualARQ display modes don’t find any true Print width attribute within the section styles attributes.

I think I may have found the issue. Here it is working in a screen cap from layout view with the monochrome display mode.

I think your file wasn’t working because the “width scale” for the object is set to 1. Width scale is a multiplier, not an actual print width, so any multiple will just be the same line width.

In the screencap above, I set the thin line at 0.1 and the thick line at 1. Then I set the print width for the polysrf at 0.1 and set the “width scale” to 10, so it will print at 1mm, like the thicker crv.

It has some workflow issues, like the section curve scales to view zoom, and we have to use this “multiplier” method of setting the section line weight, which is a strange choice to be sure, but one that at least appears to demonstrate the technical capability of the software to accomplish the task we’re pursuing.

However, none of this works in any of the VA display modes. Oddly, the hatch doesn’t appear to be working either.

Here’s a working example file. Any thoughts?

section lw.3dm (4.6 MB)

Hi Clayton, that’s interesting…
But I’m still confused (we are exchanging our roles here :laughing:.)

Are you saying the “Width Scale” section style boundary is a multiplier of the Print Width of that object?

I guess this means it is not possible to assign a “Hairline” to that object, and get a “predictable” print width to the section boundary of that object because “Hairline” thicknesses can’t be scaled, am I wrong?

Your example seems to work when the Linetype (in the secion boundary) is set to “By Layer”. But it gets out of control as soon as you select a “Custom” linetype. I wonder what is the relation with the “Custom Linetype” Width value (also set to mm).

@stevebaer can you shed some light on how this works?

We will fix this as soon as we have a clear idea of how line widths in section styles are currently working in Rhino.

This one’s going on my highlight reel, for sure!

Yes, that’s how it appears to work, at least. Which is why your file wasn’t acting as expected. With the “width scale” set to 1 there’s nothing to multiply.

Good question about hairline. Just tested below, it looks like hairline does have an actual value that’s capable of being multiplied.

One additional note, it seems like the rendering method for print preview of these section lines scales to the viewport and not to any actual “print width” unless you’re in an actual print dialog. Then it will scale accurately to be the multiple of the projection line weight. Not ideal, but working where it counts.

Also curious about this, because it could be a useful workflow for architecture where actual line weights are controlled in a separate register, outside of byLayer or byObject. Not unlike AudoCAD CTB files, but way better.

I initially thought this was the intended workflow and spent way more time than I should’ve setting up a file to operate this way before I realized it wasn’t working yet.

Glad to hear it, and I’m sure there might be some useful insights from the VA team to the Rhino team regarding how Rhino section line weights could support architectural workflows. Thanks again!

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