Experiment: AutoCPlane mode as a V5 plug-in

Hello all - we’re messing with the idea of a mode that sets the active CPlane according to the current view direction - this would be for single-window modeling for the most part. I’ve attached a plug-in for V5, Sr9+ as a prototype for this behavior - we’d love to get some feedback if you want to mess with it.

Drag and drop onto a V5 window to add the command

  • the mode sets the nearest World CPlane to the current view - Front, Right, Top, Bottom etc. as you approach a view that looks at that plane. When there is no plane within the cut off angle, the World Top becomes active.

  • most useful in a maximized perspective viewport.

  • the angle setting you see when the mode starts dertermines how close to the nearest plane’s normal your view direction needs to be before the CPlane is made active - the range is 1-44, in integers. Small numbers means it will wait longer as you rotate the view before a new CPlane is made active, and it will switch away from the current one to World Top more quickly.

Thanks for testing, fire away with feedback right here…

AutoCPlane.rhp (14 KB)



Interesting option. Thus far works as advertised. Could this be extended to named cplanes? I could see some sort of way to anoint a named cplane so that it is included or excluded from the auto cplane mode.

Hi Luis - that might be possible… I’ll take a look.



Hi Pascal,

Great feature! I wouldn’t mind this being implemented as default in the next Serengeti WIP. Thanks!

One wish: some sort of visual feedback that a CPlane orientation has been established. Perhaps the name of the CPlane in the viewport title? And a 2-color option for the active viewport: one for regular world CPlane and another for this behavior - that could probably eliminate a need for the name in the viewport title.

Unrelated but while on the topic of viewport titles. I hope that RH6 will bring us an asterisk in the viewport name when one navigates away from a named view. I took a quick check of YouTrack but couldn’t find such wish / bug report. It has been mentioned many times by many people in the past…

I will most likely wish to be able to turn it off. I work almost exclusively in the Perspective viewport and I want to be sure that the CPlane in that viewport is exactly where I last left it…


I really understand what you are saying, Mitch and I’m not entirely convinced that it will work in a real workflow.

So do I and as @pascal says, that is exactly where this would be most useful. But, yes, we need to be absolutely sure which CPlane we are on and that’s why I request a visual feedback. I would think that much comes down to finding an angle setting that works best.

As for testing in a real workflow, I’d like this in Serengeti as I only go to RH5 these days when I need to get something out of Make2D.

I kind of see this as a modelling aid like Ortho, Planar, Osnap, etc.
Perhaps we would need to think of an enable/disable button on the bottom
along with the other modelling aids, as well as a temp override such as
Shift for Ortho.

Luis E. Fraguada

Director of Research - Built By Associative Data - http://bad.ar.com
Chief Technical Officer - Robots In Gastronomy -
Chief Technical Officer - Jorge & Esther - http://jorgeandesther.com
Instructor - Institute for Advanced Architecture of Catalonia -

I see this going in an interesting direction. What I found more useful even than access to default planes was support for on the fly custom ones – based on established sub-object selection, better even on just hover over element. The idea would be that one could have any sort of complex polyhedron on screen, would somehow target a face and could instantly draw a circle with correct alignment on top of it.


i saw this briefly in seattle (if it’s the same thing i’m thinking of… they were calling it (someone’s name) mode… alex mode?)

i haven’t tried it myself but it did seem it would work for me in a real workflow… basically, i was thinking if it were toggle_able/lockable, i’d never have to leave full-size perspective viewport.

but again, i haven’t tried it out myself so…

Yep, we were calling it KyleMode, since Kyle had suggested it…


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Yes, this would be very cool - assuming, of course that the object or sub-object selected is planar.

I would probably use the auto CPlane feature with a very narrow window so that it stays in the default unless I’m VERY near to a parallel main plane.

The idea I also like - which has been asked for several times - is that you could have the view “snap” to the nearest principal plane (button, keystroke, alias) and turn into a parallel projection, and let you rotate it back off into perspective projection as needed.



Hi Mitch -
We had the current plug-in working that way for a while- if it found a plane to change to, it snapped the view to Plan and Parallel… it kinda worked but the projection change made for a pretty weird visual experience in may cases. I also could not make it snap and square up the view to Top - it was always a little skewed- this can probably be handled in real life but it made the thing too weird. However, it exists and could be tuned up, I’m sure.


Hi all - here is an updated version with a label (very flickery at the moment, sorry about that) for the current plane. Does that do any good? Should the label colors stay the same? I was hoping it would not be necessary to actually read the label once you know the colors…

@wim, @fraguada, @hifred, @Helvetosaur, @jeff_hammond @gustojunk

AutoCPlane.rhp (18.5 KB)

(Also, FWIW, testers, I find this to be much more natural feeling if the angle is set quite high- like 20 or so. I’ve not done any real work with it though.)


Hi Pascal,
here’s a sample from an app which I have configured to use a Navigation scheme very similar to Rhino. I tumble the view with RMB and snap by tapping Shift. The projection automatically changes to orthogonal. The consequence is that I need to press Shift+RMB to Pan also in Ortho views, but I guess I’m doing that most of the time in Rhino too - as it’s the way it works in the perspective view.

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Yeah, I can see how that might be good- I don’t know if I can get that fancy in the prototype, but maybe…



Thanks, Pascal!

I don’t think that we need text in there, that a color change is enough. Therefore, I really think that this should be integrated in the viewport title - not a separate box. (I understand that that is likely not to be possible in a prototype that runs on RH5). Also, for me, it’s not necessary to have different colors for all CPlanes. I think it would do if the world CPlane is one color and all others a different color.

A little buglet: in a clipped view, the indicator disappears under certain circumstances.

Perhaps a prompt carrying the Cplane name - next to the viewport name - that appears (flashes?) when you rotate the view into a cone angle near the plane normal? Then clicking that prompt would snap (and lock) you into an ortho view of that construction plane. The prompt would then stick in view, and clicking it would toggle it off and release you back into standard perspective mode.

If there’s more than one possible Cplane ‘within cone’, stack the prompts in order of proximity to the current view direction.

Something like this would also mean that you wouldn’t have to remember what you called a custom Cplane - just its rough location.

Not sure I need to get into a plan and parallel mode. Seems fine the way it works as it does right now.

started trying.
For me angle= 44 look better (with spacemouse)

The colours doesn’t are not needed if yuo have the Name popping-up.

From my point of view you can limit the number of Cplane to just 3 (Top, Front, Right).
For me you don’t need the Back nor the Bottom Cplanes.
Don’t know about the Left, for European it’s more natural than the Right.

I like the idea very a lot! Keep Working.

Yep, the whole thing is a little flashy/flickery as well. I’ve enlisted professional help, hopefully we can draw it more cleanly.