How would I go about cleaning this up so that I can fillet the hard intersection between the vertical element and the one that wraps around it? Some curves come to a point there - I could re-do it so it doesn't have the second curve. Speaking of which, can I alter the curvature/tangent of a loft or surface once it's created?



Here i've swung around to the front and zoomed out to see where it is/what i'm doing in context:



Thanks for putting up with my inane questions ;)

edit: link to file: http://www.dukecg.net/Doorhandle1_02.3dm

Hi Duke,

> How would I go about cleaning this up so that I can
> fillet the hard intersection between the vertical element
> and the one that wraps around it?

Could you please post the .3dm model file? That helps a lot to examine what you've got more than just a screenshot.

Probably the filleter does not like the edge that is pretty close to it - the one that is in the middle of those 3 curves that come to a point. One of the biggest problems with the filleter currently is that it will not cross over an edge like that so you have an edge really close to the one you are filleting, you tend to be limited to a small radius that doesn't make the fillet run into that other edge (that is kind of running parallel to the edge being filleted I mean).


> Speaking of which, can I alter the curvature/tangent of a loft or
> surface once it's created?

You can alter a loft surface after it is created by adjusting its input curves... But if you do some kinds of operations on the loft like a trim or boolean that history connectivity is broken, so you generally have to do that pretty soon after you do the Loft.

I am going to be working on making a deeper connected history in the future though.

- Michael

Edited original post with link to file :)

Hi Duke,

I think it's this edge that you want to fillet? :




If you zoom in on that circled area, there is kind of a nexus of small edges in that area:




That's not good for filleting - basically the fillet will be limited so that it must be small enough so that it does not hit any of those pieces. So basically you don't want these edges in there really at all:




It is possible to kind of bypass those edges by doing what is called a surface/surface fillet which is a slightly different way to fillet. That can be activated by using Edit/Separate on your model to break it apart into individual surfaces and then picking 2 surfaces at a time and doing Fillet. That type of fillet is not so sensitive anymore to edge structures and is built more directly following along surfaces instead of edges.

However, it can be less convenient than the edge-based one because the edge-based one knows how to build corner patches where different fillets intersect. With the surface/surface one you can need to do some more manual trimming and handling of corners where pieces meet. But in this particular case it could actually work without much fuss, here is what it looks like using surface/surface fillet to build some fillet pieces:




Again, that is by using Edit/Separate, then picking pieces 2 at a time and running Fillet. That good part about that is it would let you finish that fillet without doing any reconstruction at all I think...

When you first create that kind of stuff, try to have pieces that extend more all the way through each other and let the edges be create when they are booleaned with each other, if possible - that createes more simple edge topology. Edge filleting can't really handle complex junctures of many edges coming together very well.

- Michael

Thanks for the tips. And yeah, you're right, ideally I don't want/need those curves there at all - can I get rid of them without rebuilding the end of the handle piece?

Hi Duke, surface/surface filleting works pretty good for a part there, but then has some problems with some other areas.

Another thing that the filleter doesn't really like (as you may be figuring out now, it can be pretty temperamental) are areas where surfaces are fairly close to being smooth to another but are really about 5-10 degrees creased instead of fully smooth, like here is one such area in this shape:



For filleting, it is a lot better if a piece is actually smooth with each other, or more distinctly creased with one another.

Another related area is having things be planar that can be planar, instead of slightly warped, this one is like that:



I tried to rebuild that with a simple trimmed plane there, but that outline is just slightly warped and not actually flat.

- Michael

Hi Duke,

> And yeah, you're right, ideally I don't want/need those curves
> there at all - can I get rid of them without rebuilding the end
> of the handle piece?

You can't normally just delete an edge, because of the way "underlying surfaces" work.

Check out here for some info on that and some illustrations.

But basically the way that NURBS works, just because 2 surfaces share a trim edge with one another doesn't mean that the underlying surfaces have any kind of control point alignment with one another.

Here is an example of that from your particular piece. This surface has an underlying surface with a control point structure like this:



And the one right next to it has an underlying surface with control points like this:




On the second one you can see that the edge there is actually a trimmed out area internal to the underlying surface, and you can see how the point structure is totally different, the surfaces themselves don't have very much in common there, they just meet a trimmed edge.


One thing you can do is to select trim edges and use Delete to "untrim" the surface and recover the underlying ones. I did that on the outer pieces here and got what looks like some of your original pieces:



If that could have possibly been done as one larger revolved piece or something like that, it would have probably got better topology in the end result.

- Michael