The parameters of this fillet can no longer be enlarged, and why are these two lines in the crossing?

control c control v to duplicate the necessary curves

refine the curve with a strong break ( add points on each side and delete the central point )

join the segments of curve

do networks

join the surfaces

filet

Hi joe,

re:
> The parameters of this fillet can no longer be enlarged,

MoI is not a parametric modeling program so it does not have a function for altering the fillet parameters after it has been constructed. For that kind of functionality take a look at parametric MCAD software like OnShape, SolidWorks, Alibre, etc...

> and why are these two lines in the crossing?

Fillet pieces between surfaces will only match up with each other directly if the surfaces are smooth to each other. Since your surfaces are not smooth to each other here:



that will mean that the fillets will be of slightly different lengths where they come together so it will have to make a fill in piece there.

It sort of looks like you're constructing things in a "patch by patch" manner by building separate network surfaces between a framework of 3D curves. That kind of method can be problematic since it easily leads to creases between the separate patches. It is instead generally better to build larger and extended regular surfaces and then remove some areas by booleans or intersections rather than building surfaces directly to a 3D curve framework.

If you're coming from a polygon modeling background, see here for some tips:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael

Hi Michael

Thank you for the tips , I'm doing some exercises with MoI. and trying to do this sight, It's easy to do other part except for this place , I find it diffcult to solve with Boolean operations.

Hi joe, do you have any larger resolution images of those?

So one way to do a boolean in that area is to construct a wavy surface using something like Sweep or Loft, and then use boolean difference using the wavy surface as a cutting object.

That would look something like this (here using sweep):





Then doing a boolean difference with that wavy surface as the cutting object will cut the base object up and you delete this piece:



Leaving you with this:



So notice here that the it's focusing on finding a larger extended sheet form for the scallop surface shape. Instead of drawing in the edges and patching it in, it's a focus on the larger extended surface form and then the edges are a result of the scallop surface shape being intersected with the main object.

A few other discussions on scalloped shapes using this method here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5147.5
http://moi3d.com/forum/index.php?webtag=MOI&msg=3321.17

With this method the scalloped area does not become irregular or pinched in form as it goes through the narrow area because the narrow-ness comes from the surface being trimmed rather than constructed directly along those edges.

If you turn on surface control points for the scalloped area here, you'll see that the original sweep surface is still all there, it now has a trimming boundary on it so that only some portion of the surface is active:



- Michael

Hi Joe,

I am no pro modeller by any measure, but I think that this sight design is all booleans. I would start by a box that contains the hole main body and start to cut from there. In general, prefer thinking in additions and subtractions of solids vs contructing surfaces "ala poly modelling" style.


ps. You can import images as planes in moi and use them as direct reference.

3 network to build this round piece etc

sympa l'exercice ;)