Filet in this case is pemited?

Edit Very curious I have reload the file and all was Ok!!!
So Does exist a "refresh" function? (reinialize of Pan Rotate don't refresh that)

ps What is exactly history?
Can make this?
Object filet, modif, modif....
Replace at the end the first filet by a chamfer

What about the "cracks" in general?
Is just an visual effect due the screen definition & zoom
or model of Breps(Boundary Representation) volumes result are always "watertighness" in Moi?
Is there an option for regulate that ?

Whish list :)
A "plan work-grid (or -view)" aligned by 3points (or by view) ?

Thx
Another little question :)
What is the normal use of a volume made in a Polygonal Prog ---> transform in Nurbs --> import in MoI
(so some Nurbs surfaces :)
Select all / Separate / Select all / Boolean Union ?
(file 3dm linked: volume on the left is the "poly" transformed in Nurbs) on the right the operations line above )
Seems all vertical facetts don't weld in only one facett?

Ps Does exist in Moi an automatic function after an auto-trimming of several nurbs surfaces for delete all that not define a volume?

Coons and Gordon surfaces are implicit inside MoI or don't exist?
coons planes http://www.cs.technion.ac.il/~cs234325/Applets/applets/coons/html/index.html

Gordon surface generated by latitude curves and longitudes curves with for each one point commun with each other :)

Thx
Something curious
Curve / Revolution / Shell / Booelan Diff with a Sphere
Why the shell resulting is "open" on the Diff internal facetts ?

Remake some try, and that seems rework fine :)
3D nurbs are full of mysteries !)
Seems solution is to remake all the shell to the wished result :)

Or what happen when you clic both on the generator curve and
surface to shell?
generator will be skiped?

> One thing to be careful of when you do the revolve is to make sure that your revolve axis is snapped right on to the end of the curve.
???
Say in Font view ; a sinusoid curve vertical
For revolve I take any other vertical axe without any snap on the curve and the revolve seems oK? ;)

3 Different colors for the basic "background curves" depending of the 3 axes?
like in this crazzy nurbs car's tut
http://www.etereaestudios.com/docs_html/nixus_htm/nixus_makingof_mp01.htm
(you can clic on the little up white triangle for more images :)
He uses directly curves and surfaces as "3D sketch" for research design !

another crazzy nurbs car tut by the same guy
http://www.etereaestudios.com/training_img/sentinel_tutorial/sentinel_tutorial.htm

Ps Little question
How use the "Circle tangent tool" for have a circle tangent between the "big rectangle" and the "big circle" and touching 2 precise points?
(the center of the little circles) ?
(because when a point is yet drawing on a curve, this point can'be choosed as first point of a curve of the tangent tool :)

If exist of course, seems not in this case of the little circles, but in the general way?
Like the 2 points (center of the little rectangles)
This last one exist
( I have drawing the circle tangent first and draw the little rectangle by centers after (curve "on" + intersection) , erased the circle :)

Or I must read a geometry's manual for construction of particular figures :)

< right now you have to just draw a regular line for that
And this line will be skip when you export your model because it was not a surface
And carreful even a triangle of 3 lines will not "export" too if you have not make a "plan" between them :)
Different than a normal save in 3dm where lines will be saved even they are not made a surface :)