Modeling Strategy

Hello Rhino Users,
I am trying to model an airplane, which has a great significance to me. Eventually, my plan is to turn it into 3D printable parts and print them, just like commercial plastic models. This project is not for commercial purposes, though. It is purely for personal reasons.
I am an experienced designer with extensive knowledge in “solid” modeling software. I want to experiment (and eventually get good at) with surface modeling, which I believe gives more control over smooth surfaces.
I watched every tutorial I could find out there, especially @sgreenawalt tutorials were helpful.
Relatively new to surface modeling, what would be your workflow to make this project happen?
Thank you.

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Therefore, you’ll be seeking nice mesh permutations per part/print.

I used to think that means something different too. Maybe you’re referring to the parasolid kernel or something which is kind of a mystical being, but Rhino reveals the truth, and truth is what you think is ‘solid’ isn’t necessarily solid. Unless the devs exploit nurbs-volumes or maybe more voxels or somem. :face_holding_back_tears:

I think I’ve seen a few users do weird solid stuff in GH.

Yeah. don’t meshes have a surface though. I mean if you think about it, if you print a mesh and then sand on it with sand paper, it has a surface right? :thinking: :thought_balloon:

Nomenclature is fun.

And then you can’t really see a surface in Rhino without Rhino shading it with a render-mesh behind your back with some odd settings until you find them hiding somewhere and change them, knowing you’re actually just seeing a mesh and not a surface. :joy:

That’s awesome. There’s tons of data these days to digest.

Very good question. Be ready to go down the rabbit hole.

If you have access to an airplane, take a bunch of photos and use photogrammetry or 3D laser scanners, or LIDAR etc.

or get some specific views and maybe subD approach.

You might even find models already done on certain websites for free or even small fee.

might be able to use AI and photogrammetry all the photos on the internet haha:

a nice side view is a good start with some subD tracing:
https://www.jetphotos.com/photo/10657282

almost a good front view:

for $3 you could download an stl mesh:

here’s an obj for $17:

Thank you so much for the reply.
I do not have an access to the airplane. I used to, but not anymore. I have tons of photos, both from the internet and my own. No quality blueprints to use for tracing, either. Just a scan of a very poorly manufactured plastic model kit.
Instead of buying the 3D model, I would like to model it myself. There is only one I could find, but it is really crude to my taste. Besides, it is my motivation to learn surfacing more.
It is MBB 223 Flamingo, which is not quite popular.
I may give the SubD a try…

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as long as you get a side view, front view, top, bottom, back, you can use:

and set them up in the workspace such that you can carefully turn the 2D images into 3D.

also, I just stumbled on this which is interesting:

I was tryna find some threads on this method of the picture/pictureframe:

I know there’s plenty of tutorials that demonstrate it.

image
definitely seems hard to find good images. although I’m not sure what the rules are for said project.

This is a good series of tutorials for aircraft:

image

https://www.oocities.org/stevensanvito/rhinotut.html

Rhino3D Aircraft NURBS Professional 3D Modeling Course

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Thank you so much.
I will look into those.
Best,

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When modeling an artifact such as an older airplane while trying to retain good fidelity to the original, it is important to understand how the work was approached originally and to try to duplicate those methods in your fancy new CAD tool. Designers of light aircraft from the heyday of airplane design did not have access to surface modeling software and the capabilities of any CAD they might have used were very primitive. For example, the benchmark CAD program of the 1990s, AutoCAD, could not even draw an ellipse properly until version 10; prior versions used an approximation using arcs. It is quite likely that the airplane you’re modeling employed nothing more exotic than a drafting table and some simple tools, perhaps some trigonometry was used to draw the cross sections of the turtle-deck and canopy, and, of course, the airfoils were drawn full-size in the loft by bending physical splines (made of wood) to bridge between coordinate points made firm by hammering nails into plywood. Stretch-forming wasn’t introduced to light airplane manufacture until the Piper Malibu; before that, the English Wheel and the Planishing Hammer and shot bags were the “fancy” metal forming technology, and rarely used on production planes. Flat-wrap sheet metal and occasional developable surfaces were the rule. The most complex part would be the canopy mold, hand-smoothed in modeling clay from a keel former and some cross-sections. And primitive molded fiberglass could be found on wingtips and wheel pants.

Don’t over-think your technology. Get good at extracting dimensions from your collection of photos and noticing minor, often imperceptible details, such as: is the line along which the tail cone bend begins a vertical one, or does the bottom of the fuselage begin to taper at a point further forward than that at which the top of the fuselage begins its taper? This is a common technique to make a slab-sided, sheet aluminum fuselage look more “svelte and sexy.” At the end of the day, nothing on these planes was anything more than tangent continuous and, often, even tangency was an illusion interrupted by joints of overlapping sheet metal.

Yours is not really a task of “surface modeling” at this point, but one of attention to detail. Noticing where the flat-wrap curved surfaces of the upper cowl and turtle-deck change from one radius to another to make the “personality” of your model match that of the real thing is what will keep you up nights.

Good luck, and try not to let perfection keep you from completion.

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Thank you so much for the wonderful advice. As you have said, it is all about reading the geometry from the actual airplane. I am really good at that, if I say so myself. Coming from another CAD package, I am having a hard time translating what I can observe from the actual airplane into meaningful geometry in Rhino. It is the frustrating part, unfortunately.
Tutorials (some are paid) that I watched were too “arbitrary” for my purposes. They definitely help, but not what I have in mind. I would like to make “plastic injection” quality surfaces and pieces. Just like scaled plastic models, so I can print and assemble multiple times.

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The advice from @davidjgall is excellent. Most of the surfaces in the model appear to be flat surfaces or simply cuved surfaces created by bending sheet aluminum over frames without stetching the metal. The latter would be “developable” in the actual aircraft but for your purposes a simple loft or sweep should have sufficient accuracy.

I would start with the lower fuselage and wings, then the upper portion of the fuselage, followed by the more complex cowl and wing tips. I’d leave the canopy till the final stages before adding the details of the air inlets and outlets and similar.

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Perfect advice, as well. Thank you.

How would you guys approach this wingtip? I am struggling, to be honest. Especially, where the clear plastic blends with the main surface of the wing.

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Here is the my take, which is not really pleasant.

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Well that seems more or less like how it is, it just needs to be rounded off…it’s more rounded on the lower than upper edge.

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LIDAR.
:coffee:

What would LIDAR do? I’m not aware of a modeling method named LIDAR.

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lasers etc. :coffee: :face_holding_back_tears: bbl sry had dayjob stuff ta do for a min lol

Unfortunately, I don’t have any access to LIDAR. These are the images I found on the internet. I am trying to model this and learn the “fine points” at the same time.

There’s a couple other apps, I’d recommend, too. But iRhino keeps getting better n’ better. :face_holding_back_tears:

The other app I’d recommend is ‘Scaniverse’ cause I actually proved that one out. There’s a few others but I hadn’t really proved them out yet.

Here’s example:

Thank you for the suggestion. It may be very useful for my future projects. However, I mentioned in one of my replies, I don’t have access to the actual airplane, either…

Hello,
I am stuck, again!!! I am trying to create this (indicated with red lines) blend, but no success… Other unedited pictures can be seen above (earlier in the thread). Could one of the Rhino gurus point me into right direction?

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