Why are fillets so bad?

I’m guilty of admitting that we have been hired just to do this, quite a few times, at the 11th hour of a project that we didn’t even design or model. And it was right before or during tooling was being made. Usually hight-touch products designed and modeled in very expensive software, where one or two surface transitions didn’t look quiet right.

We love those mini-projects!

G

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great stuff! thanks for sharing these- loft is so often overlooked…

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I don’t know if that’s off topic but
A few month ago I exported my model in step, and imported it into plasticity to put a fillet on one of my model, I then exported it again in step and imported it in rhino, a bit tedious but it worked.
Obviously you have to change programme to make it happen and plasticity has a cost. (I’m sure it would work with freeCAD tho)

But maybe this brings two potential solutions:

-Would it be possible to have a parasolid module in rhino and when you select the object on which you want to put your fillets, it would freeze enverything else, convert your selected polysurface into a parasolide, then you can apply your fillet ‘hassle free’ like in any parasolid software, and when you’re done it reconvert it into a nurbs like if you imported a step file.

-Second option would be to create a live link plugin (similar to keyshot) to another software like freecad or plasticity to do your fillet temporarly… it would have to be a two way live link.

Just throwing ideas, don’t know if it’s actually possible :upside_down_face:

good question.

someone should make an eto framework.

:beers::grin: :beers:

If you wanted to get it parametrically, I just posted a possible solution HERE

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Rhino needs some kind of solid modeling mode where all the tools needed for solid modeling is simply laid out easy to understand and shortcuts comes up in one corner where software recommends different shortcuts. As it is now its just way too much stuff going on in the UI at the same time. I’m new to Rhino since winter. I took the winter to learn Rhino and started to figure it out.
We use Rhino at our CNC factory now mainly due to all import and export formats available as customers also have Rhino or other CAD software and importing from other software and exporting for CAM software for cnc machining is a blast with Rhino.
For solid and surface modeling not so (except for SubD).

A few weeks back I had a customer project which came in half done and I had to finish the drawing for him in Rhino. I did that in 50 min. A few days later the model got sent to our CAM software for cnc, and there were still curve connection issues as the toolpaths didnt go through completely, even I joined all curves to a closed curve and made a solid. There were still a tiny small gap which the CAM software didn’t like. So we had to fix that too which took 10-15 more minutes.

I have been playing with Plasticity this weekend, started on friday after work, and today I decided to retry the customer model and imported the STEP as the customer gave us. It took me less than 10 minutes to fix and complete the model and make it a solid. I decided to purchase Plasticity as my secret weapon to do small modelling for this exact reason.

I wish I didn’t have to, which is exactly why Rhino should have a solid modeling mode. All the tools are there, its just the presentation of the tools and ease of use and make chamfer and fillets work on a solid model, not like filletsrf where we gotta fix the damn corners, not to mention if I want to adjust the top face where the fillet sits and adjust it, it breaks the model.

The solidmodeling mode could have partial parametric constraints to allow flexible adjustments of faces where fillets and chamfers have been set.

On the other hand, Rhino got a ton of functionality which offcourse Plasticity doesn’t have like Sweep2 or grasshopper, and a ton more.

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I totally agree. I see too many examples that focus on technicalities that look just plain bad. Focus on form!

I also design my products to avoid the usual crazy intersections that cause filleting issues … in the first place.

Bollocks

He’s 100% right. Solid modeling as a tool is mostly based around additive and subtractive operations on simple solids. If the booleans and fillets don’t work, the workflow is entirely broken. Surface modelling as a tool is for building solid objects face by face. Booleans and fillets are nice to have, but you can get by without them and they’re not the intended workflow.

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This reminds me of when I first learnt Solidworks back in 2006 I think it was. I wanted a 3mm fillet on the model and a message pops up saying something along the lines of “sorry, can’t do it. Try a different size”. But I didn’t want a different size, so I went back to Rhino and added the fillet that I actually wanted.

Sometimes I wonder if the complaining about filleting in Rhino is mostly about the FilletEdge command, as the FilletSrf command seems to be pretty unstoppable. Yeah, get the occasional time a little extra work is needed, but it never pops up a message telling me to give up.

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There’s no bragging rights when you can’t do stupid fillets. It should work. Point.
Enough with that “Surface” vs “Solid” bullshit.
There’s no solids, not more than there is a spoon.

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I agree with @osuire there is no reason why this should not work in Rhino for the reason being a surface modeler. It causes a lot of pain for many users, both beginners and advanced. Sure this is fixable in Rhino, but it takes quite a bit of knowledge, and when you decide the fillet needs to be 1mm bigger, you can do it all over.

You can see that in that model, there is no reason for it to fail either. The right lower corner fills correctly, while the lower left doesn’t. And that’s the most painful one to do manually. The other two are a quick fix, but since those surfaces are able to trim the corners correctly, there is no reason there it should fail either.

Furthermore, improvements to fillets are at the top of the list of user requests as long as I can remember.

Edit: the above refers to the other thread

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Creo, solidworks, fusion360 etc. all have surface modelling capabilities - you can switch between the two to suit the design so if a fillet fails you can model it in by hand with curves & surfaces.

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I had a very similar experience, but I didn’t start learning Rhino till about 2008-'09 :slightly_smiling_face:

I remember the other CAD’s not being very good at filleting either, to be honest.

Indeed Rhino enables the user to make any shape possible pretty much, so technically it’s the user that’s bad if they can’t fillet.

I think we just would like Rhino to do it automatically I mean is that too much to ask hahah :joy:

I’m sure it’ll happen eventually, cause I’ve seen lots of amazing scripts and stuff, just need the devs to keep making them better and charge me money :money_mouth_face:

Very good point. I left those other CAD’s behind back when they first started having those features introduced, and I never bacame very good with CATIA surfacing abilities.

But I chose Rhino, and couldn’t really ever justify the cost of the other CAD’s and probably never will.

I’ve seen plenty of fillets fail in other CAD’s. So, I’m fine sticking with Rhino and squeaking when it wont automatically extend or trim an edge, until we get some more scripts or something to grease the wheels. :smiley:

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Another instance where Rhino fails but other cad software manage to fillet:

Grasshopper approach instead?

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Even though this is not a fillet, it shows the same issue I have with fillets that are supposed to end into a single vertex. In the majority of times, the resulting surface’s tip is shorter, distorted and won’t reach the expected end point. Control point editing is necessary to fix the failure. The ! _SetPt tool does the job most of the time, but the whole process is slow and tedious.

Starting from 38:25 minute of this video, I solve two of those bad surfaces.

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I agree it is tedious. ps: If you want to zoom into that corner I recommend using _Zoom _Target as this sets the camera target closer to where you want to go than _Zoom _Selected.

I’m aware of the zoom target command, but it does not work properly with my 3d mouse (3Dconnexion SpacePilot), because the latter immediately sets the camera target in another location that it “thinks” is more appropriate. :slight_smile: It causes some conflict with the clipping plane.

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:star_struck:looks good :beers: parametric fillets :smiley:

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