Power Filleting

Power Fillet Overview:

Power Filleting provides Rhino with filleting tools typically only found in powerful high-end modeling software. 

Power Filleting for Rhino enables the following advanced filleting functionality:

  1. Variable Radius Filleting (single VR fillet over Tangent Edges is Possible)
  2. Many large radius cases where the fillet intersects something or self intersects
  3. The selection of different fillet radii, fillet types, cross section curve types for a single filleting operation
  4. Constant Radius, Constant Distance and Variable Radius fillet rail generators.
  5. Rational Arc, Approximated Arc, Linear, and Blended fillet cross section curves

Power Fillet Usage:

  1. Either type "PowerFillet" in the command line or select "PowerFillet" from the "nPowerSoftware"
    menu on the main menu bar.  Then select the Solid or Open Shell you wish to fillet.  NOTE: It may
    ask you to split the object at G1 continuities.  Typically this will give you the best quality results
    in filleting if you accept this and hit "Return".
  2. Type in a Fillet Radius for the first set of edges.
  3. Choose the Fillet Type (Constant Radius, Constant Distance, or Variable Radius).
  4. Choose the Cross Section Type (Circular Arc, Non-Rational Arc, Chamfer, G1 Blend Curve
    or G2 Blend Curve, or G3 Blend Curve).
  5. If you are not doing Variable Radius filleting you can now start selecting edges. 
  6. You can then change the Radius and select more edges.
  7. Once you hit the "OK" button Power Filleting saves a copy of the Original Solid and the filleting
    parameters.  To change the fillets select the resulting object and select "PowerFillet".  You can
    associate a Power Fillet command to any number of objects. 


Select Assign Edges to start Picking Edges
 

 

 
Note that the selection of an edge automatically selects other tangent edges.  In this case the
selection of the line also puts fillet circles on the tangent arc and other line. 

 


This is the Result of the three tangent edge fillets.  Note that the fillet rolls over the hole.  This
is one of the large radius cases handled by Power Filleting.

 


The user can select different radii for individual edges or groups of edges as shown here.


Here is the result of filleting with different radii.  Note the fillet rolling over the rectangular hole and
the fillet radius being larger than the lower right hand surface.  Note that a blend surface is created
in this case.

 


There are two ways to specify a Variable Radius Fillet. The first is by selection along an edge
to be filleted.  Use the "Along Edge" button to use this interactive technique.  Note to enable
the "Along Edge" button you need to select the "Variable Radius" Fillet Type.2

 


Along the Edge first asks for you to select an edge.  Once done it asks you to select points
along the edge using the mouse.  The first point needs to be at one end of the edge, the second
needs to be the end of the edge.  The second point (end of the edge) is selected automatically
after the first point is selected (using the opposite end of the edge).  After you define the start 
and end you can specify interior radii.  To complete the definition you can hit the "Return" key. 

 


As you are selecting points along the edge you can change the radius for the next point to
be selected by typing a radius into the PowerFillet dialog box, or into the Rhino command 
line and then hitting return.  Here we have changed the radius from 1 to 2 for the end point.

 


The final "Along Edge" selection might look something like this.   If you have problem remember
to be careful to specify the two end points first.

 


This is the dialog display after "Along Edge" selection.  Note that the percentages and Radii
are displayed in the list box.  You may edit either the percentages (must be between 0 and 100)
or the corresponding radii and reselect the edge to effect the change.  Note that it is possible to
remove individual edge fillets using the "Un-assign Edges" and to remove all edges using the
"Un-assign All" button.  The "Assign All Edges" button assigns the current filleting parameters
to all edges in the object.

 


Here is the result of the variable radius fillet.

 


You may also type in percent/radii pairs in the "%,Radius Pair(s):" edit box.  You can type in
several as shown here or one pair at a type separated by comas.  When you select "Add Pair(s):"
the pairs will be sorted and added to the list box.  Note that you can edit the values by clicking
on the pair you wish to edit.  You can also delete a pair or delete all pairs.  Note that the values
shown in this box only applies to edges yet to be filleted.  If you want to change a variable radius
fillet of an edge you must reselect the edge.

 


This shows the result of the variable radius applied along the 3 tangent edges.  Note that the
order of the Fillet Radii depends on the selected edge.  If we selected the top edge instead of
the side edge the shape of the fillet would be reversed.

 


There are different cross section types that may be used.  Normally filleting is done with
either a circular or linear cross section.  We also provide a non-rational approximated
arc and a blend curves (G1, G2, G3).  The "Buldge" of the Blend Curve can be adjusted 
to produce various effects.  The G2 Blend Curve uses the second derivative of the adjacent
faces to produce a smooth, continuous curve.  The G3 Blend Curve uses the third derivative
of the adjacent faces to make the rate of curvature change continuous across the boundaries.
The following illustration shows the same filleted elbow with each of the Blend Curve options. 

 


The elbows are shown in both a shaded representation and with the Rhino zebra display.
The elbows on the left use G1 Blended Curves, while the ones in the middle use G2 Blended
Curves, and the ones on the right are G3 Blended Curves.

 


This object has the Circular Arc Fillets.  Note how the fillet surfaces tend to stand out because
of their constant curvature.

 


This object has the G1 Blend Curve fillets with the same offset radius (0.8) which produces the same
rail curves.  Note the reflective properties of these fillets gives the object a more natural look as
opposed the manufactured look of the Circular Arc fillets.

 


Here we have used a linear cross section to produce this chamfered object.  Note that linear
cross section is often used with the Constant Distance fillet type. 

 


This object shows the G1 Blend Curve cross sections with a weight of 2.0.  It gives a very nice 
kind of a worn edge appearance.

 


Here is what a G1 Blend Curve cross section looks like with a weight of 0.4.