Hi Laurent,

> The thing is how should i model a watch for example in moi
> to be able to have fillet everywhere it's needed ?

Well actually your posted model is can be filleted as long as you use a small enough radius.

And for a larger radius you were pretty much all ready to do it, you just introduced edge fragmentation by doing some of those partially-sharp-juncture fillets since you only filleted some of the edges that met at a juncture instead of all of them.


So you're actually pretty close there to having the overall technique down well - sometimes the physical geometry of how fillets work can take a bit of getting used to like just the fact that the fillet surfaces from 2 "constant radius" fillets do not necessarily line up to one another when they collide into one another when the surfaces on either side are at different angles to one another.

That's because although all the fillets are made up of arcs of the same radius, when the angle between surfaces changes it will make the fillets to be constructed out of a larger or smaller piece of that same radius arc.

See here for some examples of this geometric situation:

http://moi3d.com/forum/index.php?webtag=MOI&msg=3150.24
http://moi3d.com/forum/index.php?webtag=MOI&msg=2457.2


If you don't have a lot of prior experience with how "constant radius" fillets work, it could be easy to think that any fillet surfaces of the same radius will match up physically where they collide into one another but that's not true. Once you get a bit more familiar with some of these geometric side effects you won't end up doing partial stuff that ends up fragmenting your previously cleanly constructed model so much.

You will certainly still curse at fillets plenty though even when you have more experience, it is definitely a finicky area. But you're not far off from being able to make regular stuff work better....

- Michael

Hi Laurent,
""""""Can i ask you what was the way you proceed ?""""""""

For the model i posted, you can just select the entire model and run fillet .02.

Michael gave a good explanation. If you wanted to start doing "edge fillets", these will succeed too, but you have to pay attention to selecting "all the edges" that play into the surfaces in question. It can also eventually lead you into a corner where you are left with an edge that cant be calculated. Viacad is really good at doing these segmented edge fillets and completing a result.. If you want to start selecting several single edges and running various fillets in different areas, it will require more time spent. You will have left the push button fillet arena so to speak.

Here's a quick video to show a failed edge selection, then one that succeeds.



Here's a screen grab of a single edge selection. Note that selecting just this edge will fail a fillet. But, look what would have to change for a fillet to go "only on that edge!" Selecting the little curve in the adjoining fillet will allow the filleter the knowledge to create a little cap there.



Also, if you start looking at it from a single edges picking fillet process, you can see how you can get backed into a corner. At this corner, you would need to practice more advanced, lower level modeling techniques to finish.

Cool tricks ;)

thank you all for your help.
i'll continue training.

Laurent