Hi all

So for my model I need to make a fillet, but not a circular fillet...



Where the yellow line is, I want that moved back more - (fillet radius of 0.75, but I want a higher distance for the yellow line), if you know what I mean.

You can do what I want with the chamfer tool, but I'm not sure why you can't do it with the fillet tool? Maybe I'm being silly and have forgotten something simple :)

Is there a way to do what I'm trying to do?

Also, as a side note, is there any reason why that yellow line I have won't be automatically selected by the "select curve loop" command? The parent loop was selected like that fine, but the filleted line won't select with taht command :(

And while I'm at it :P
Is there a way to do a filler / chamfer where it will fillet/chamfer to 100% of what it can, and meet up (and join) with the limiting edge it's colliding with?

er... I should try to explain that...



So in that example, I want the fillet to meet in the middle, instead of having a gap (currently that's a fillet of 0.35, where about 0.39 is almost completely sealed).

So what I'd ideally like is a sinlge join curve in the middle, where the 2 fillet edges meet. Maybe a tick box to say "fillet / chamfer as much as possible"?

(same goes for creating a fillet or chamfer with 1 edge, where you want that to fillet /chamfer as much as it can)

Hope that makes sense!

>>You can do what I want with the chamfer tool, but I'm not sure why you can't do it with the fillet tool?<<


Use the chamfer tool to produce the size(offsets) you want, then delete the surface created by the chamfer, select the 2 edges that where produced(from the chamfer) and use Blend.


- Steve

Hi NightCabbage, well the difficulty with "2 distances" on fillet is that a regular fillet wants to put in a circular arc as the rounded shape, with the arc being tangent to the pieces that it is touching.

In order to have a "2 distances" variation of fillet I guess you would want something like an ellipse shape or something like that rather than a circular arc piece? But that's somewhat unusual in the CAD world to have an elliptical fillet so right now there is not any option for that in the geometry library that MoI uses.

So probably your best bet would be to do what Steve mentions and use Chamfer, then delete the chamfer and put in a surface blend instead.


> Also, as a side note, is there any reason why that
> yellow line I have won't be automatically selected
> by the "select curve loop" command? The parent loop
> was selected like that fine, but the filleted line won't
> select with taht command :(

It's hard for me to know for sure without testing the actual model - could you please attach the 3DM file so I can test with your model?

But possibly the edge you initially selected was a joined edge belonging to 2 loops - in that case you need to select 2 adjacent edges so that you more clearly identify which of the different possible loops you want to target.

See here for some examples:

http://moi3d.com/forum/index.php?webtag=MOI&msg=3112.22
http://moi3d.com/forum/index.php?webtag=MOI&msg=3112.32


> Is there a way to do a filler / chamfer where it will fillet/chamfer
> to 100% of what it can, and meet up (and join) with the limiting
> edge it's colliding with?

No, there's no way to do this currently - the filleting engine does not like to entirely consume and eliminate faces like this.

From what you are describing you may want to do something like draw the middle curve and then do something like sweeps to build the side surfaces, rather than using Fillet for this kind of thing.

- Michael

Steve - good idea, thanks :)

Michael - Yes, I was thinking that because the fillet tool supported non-circular shapes (you currently have Circular, Const Dist, G1 Blend, G2 Blend, G3 Blend) I figured that you were already able to do non-circular fillets?

I have attached a model with the loop selection problem (I was using 2 curves to try to select the loop, but no luck).
Try selecting the loop like I had in that first pic above - I have to do it manually.

> the filleting engine does not like to entirely consume and eliminate faces like this.

Is this a possible feature for the future? I find that I do a lot of this :)

Thanks as always Michael!!

Hi NightCabbage,

> I figured that you were already able to do non-circular fillets?

Yes, a couple of specific kinds - but unfortunately each different kind of special fillet shape requires a lot of special case coding particularly for how things should work in corner patches when fillets collide into one another (when multiple edges come together into a shared endpoint).

Just having a couple of existing non-circular fillets unfortunately does not mean that just every kind of other non-circular fillet is automatically handled...


> I have attached a model with the loop selection problem (I
> was using 2 curves to try to select the loop, but no luck).

I see - so the problem you're running into here is that the loop selection currently will only select a trimming boundary loop that's all part of one face. The loop that you want to select there isn't just one face trimming boundary, it's a bunch of edges that belong to many different faces.

In the future I'd like to make loop selection work on cases like that as well but currently it does not handle a chain crossing over multiple faces like that.


> Is this a possible feature for the future? I find that I
> do a lot of this :)

It could be possible - it's not really up to me though, the filleting that MoI uses comes from the Solids++ library, and I'm relying on them for updates to it.

But filleting is an extremely difficult and time consuming area of work so progress tends to be kind of slow and incremental in this particular area.

- Michael

Ok thanks Michael :)