Hi Tony - what radius of a fillet are you trying to create?

There are several different issues on your particular model here that will make it difficult to fillet.

One is that your object is quite thin and so only a fillet of a very small radius would even be possible to fit on it.

But also another thing that will probably make it difficult is that your model seems to be made up of multiple fragmented pieces instead of bigger smooth surfaces, for example see these vertical edges here:




The front surface of your model there is not just one big surface but is instead made up of multiple surfaces, and filleting will tend to have difficulty handling situations where you have multiple surface fragments like that where the surfaces are not totally smooth to one another but are somewhat close to being smooth like meeting each other in a shallow 5 or 10 degree angle or something like that.

When 2 surfaces touch each other totally smoothly then it's ok since fillets that are constructed will touch each other naturally where they meet up.

When surfaces are sharp where they meet, then fillets do not meet up naturally and instead they need to have a lot more processing done with fillets getting extended and intersected with one another and then corner patches put in to then connect up the trimmed back pieces. All this stuff is much more difficult to handle when things are meeting at a shallow angle, things like the corner patches become little tiny slivery things and it's also more difficult for the intersector to do a good job when things are at such a shallow angle.

So anyway, in order to fillet this you instead want the front and back parts of your model to be made up of bigger surfaces instead of fragmented into smaller pieces.

It looks like your generator curve that's flat on the x/y plane is made up of a lot of little different sub-segments. If you select it and then run Edit > Separate on it to break it into its individual segments you will see that a lot of small pieces are then individually selectable. That segmentation in the generator curve is going to cause segmentation in the surfaces generated from it, so you want to get that generator curve to be better constructed before building more stuff off of it. Probably the easiest way to tune it up is to use the Rebuild command on it:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#rebuild

So anyway probably your model as it currently stands is going to be quite difficult to fillet - I would recommend reconstructing it to have a cleaner construction with a smaller number of broader surfaces rather than having it made up of so many different fragments.

- Michael

If you want the entire object to have rounded edges, it might be better to export it like it is and import it into Blender, where you can perform Subdivision Surface smoothing on it.

http://www.blender.org/

If you're not familiar with Subdivision Surfaces, here's a vid that explains it.
http://www.youtube.com/watch?v=ckOTl2GcS-E&feature=topics

Steve S

Michael tried to reconstruct the curve better nn but I still understand how the fillet
I posted the new file ....... sorry but I can not understand

Hi Tony - your new version looks to be more cleanly constructed.

I just loaded it and I can fillet it over here ok by just selecting the entire object and then using a radius of 0.01 units:




What fillet radius are you trying to use, are you possibly trying to use a value that is too large? Your model is made up of a lot of pretty thin pieces, so there is not enough room for fillet much larger than 0.01 to actually fit in the available space on the model.

If you examine the result of the 0.01 fillet you can see that it is still having to put in some fairly complex corner junctures in some areas like this area here:




That's happening because your model is not smooth in that area - it looks like your original curves come to a sharp but somewhat shallow corner in there, if you zoom into your model in that area you can see this:




That kind of "sharp and shallow" feature of the outline is not so good for filleting, it makes the filleter do a lot of extra work in those areas. It's better for something like that to be fully smooth or more distinctly sharp instead of just slightly sharp at a shallow angle like you have it now. In your particular case here it was just sharp enough to allow it to be filleted ok, but that's still an example of the kind of thing you want to fix up in your original curves before you actually construct solids or surfaces out of them - having your original curves be higher quality and smooth in areas like this will then make filleting of things constructed from them later on go a lot better.

So there are still some aspects of the model construction that could be improved even more.

But anyway, the model you posted does seem to fillet ok over here just as long as you ask for a small enough radius that will actually fit in there.

- Michael

Thanks Michael ;)