Hi all,

I am having problems with the filleting of polysurfaces in Rhino and I am wondering if MoI can help me.

I'm looking for the fastest way to round the outer edges of my designs.
Right now with Fillet edge in Rhino I have to manually correct all the different edges with the proper radius, and I would like a way to automatically apply the widest possible radius to all selected edges.

Here are 4 links to images to explain.

1. This is the kind of shape I work with (letter combinations). I import it from Illustrator
https://picasaweb.google.com/106473353266318074759/April212013#5869208671103729970

2. From that I extrude a solid, but I want it to have round edges.
https://picasaweb.google.com/106473353266318074759/April212013#5869208740332716178

3. This image shows where the problem is. Even if I correct each radius in the preview the result is pretty bad.
https://picasaweb.google.com/106473353266318074759/April212013#5869208843445791330

4. This image shows another problem in Rhino
https://picasaweb.google.com/106473353266318074759/April212013#5869208866213761330

Please let me know if MoI can do a better job with this.

Thank you,
Seb

Hi Seb, I can't seem to connect to any of those picture links, I get an error: "Sorry, that page was not found." for each link.

MoI does not have any mechanism in it to automatically find the widest possible radius for filleting, so it would not really help you for automating that particular thing really.

Actually one of the features of MoI's filleting mechanism is that it tries to allow fillets of actually greater than just the tightest radius bend in the edges and will try to put in a separate kind of blend in those places, like this:

Here's a shape with a tight bend in it:



A regular fillet can go up to about this radius here before the fillet will start to cross over itself:




But MoI's filleter will actually allow you to go to a higher radius than that, it will break the fillet into pieces that stop before running into that tighter bend and put in a separate kind of blend in that spot:



So because of that the max radius for this particular shape is something like this:




So I'm not quite sure what you are looking for by "maximum radius" exactly - do you mean something like this here where the fillet may be eating away a big part of the object or do you mean the maximum radius before the fillet would have to start being broken up into several pieces like shown here?

It could be possible that MoI could be useful to you, but MoI's filleter can also be sensitive to a lot of things as well and it's not unusual for font shapes imported from illustrator to have a lot of things that are pretty difficult to fillet in them, things like excessive segmentation and pieces not meeting completely smoothly and stuff like that - MoI's filleter will have difficulty with those kinds of things too.

- Michael

Another thing that makes what you're asking for about automatically doing the "maximum radius" fillet is that it's not unusual for the fillet to be kind of a bit mangled or poorly formed when you're trying to generate one with a radius that is right close around the neighborhood of where it starts to cross over itself. It's easy for the cross sections of the fillet surface to start to pinch together as they get close to crossing over each other and so shooting for that exact maximum spot is probably going to have bad side effects.

Something like ten percent less than the maximum or something similar to that would probably be a better target...

Anyway that's another complicating factor in what you are describing.

- Michael

Thank you for you replies and sorry for the images snafu.

I am not really looking to have the "maximum" radius automatically applied, but I'm looking for a a way to fillet these edges that is faster than Rhino, which is very time consuming for this task. I would need to prepare many of these each day, and I have to actually produce these afterwards so I don't have much time to deal with the fillet.
I wanted to know if MoI can do this faster and better than Rhino

I've uploaded the images this time:

1. This is the kind of shape I work with (letter combinations). I import it from Illustrator


2. From that I extrude a solid, but I want it to have round edges.


3. This image shows where the problem is. Even if I correct each radius in the preview the result is pretty bad.


4. This image shows another problem in Rhino

Hi seb, so it's just the outside border that you want rounded?

The things you are showing there will be difficult to do as an automated process in any CAD program I think...

Things like sharp small features such as this:



will definitely be problematic, and you'll run into the same kind of problems that you described about if the surface below pieces is too narrow.

Maybe you should try something more like a 1-rail mitered sweep around the outside boundary rather than doing filleting... But actually sweeping will also run into some similar problems from trying to fit a large sized round arc piece around a small tightly bent hook shape.

I don't really see how that's going to get automated very easily, it's difficult for an automatic process to handle all the kind of "running out of room" problems that occur with something like that.

- Michael

Thanks for your reply.

Yes I was asking just in case, but I guess MoI and Rhino handle filetting pretty much in the same way.

I'm trying to see if I could have a Rhino developer make a script for this, but don't have high hopes...

Thanks anyway