IGA - Where have my corners gone?

#1

Hi

Hopefully quick one, I’ve got a geometry (image and script below) and Im wondering where my sharp corners have gone :wink:

image
image1185×553 21 KB 

#!python
cubit.cmd('create Cylinder height 1 radius 1 ')
cubit.cmd('create Cylinder height 1 radius 2 ')
cubit.cmd('create Cylinder height 1 radius 3 ')
cubit.cmd('brick x 8 y 8 z 1')
cubit.cmd('subtract volume 1 from volume 2 keep_tool ')
cubit.cmd('subtract volume 2  from volume 3  keep_tool ')
cubit.cmd('split body all')
cubit.cmd('subtract volume 6  from volume 4  keep_tool ')
cubit.cmd('split body all')
cubit.cmd('delete volume 1')
cubit.cmd('delete volume 5')
cubit.cmd('delete volume 8')
cubit.cmd('compress id all')
cubit.cmd('volume 1 2 3 scheme map')
cubit.cmd('imprint body all')
cubit.cmd('merge all')
cubit.cmd('webcut volume 3 with plane xplane offset 0 ')
cubit.cmd('webcut volume 4 3  with plane yplane offset 0 ')
cubit.cmd('imprint body all')
cubit.cmd('merge all')
cubit.cmd('volume 3 1 6 5 4 2  size 1')
cubit.cmd('webcut volume 1 with plane yplane offset 0 ')
cubit.cmd('webcut volume 7 1  with plane xplane offset 0 ')
cubit.cmd('webcut volume 2 with plane xplane offset 0 ')
cubit.cmd('webcut volume 10 2  with plane yplane offset 0 ')
cubit.cmd('imprint body all ')
cubit.cmd('merge all')
cubit.cmd('volume all size 1')
cubit.cmd('volume 6 3 4 5 size 0.5')
cubit.cmd('volume all scheme submap')
cubit.cmd('volume 6 3 4 5 scheme map')
cubit.cmd('mesh vol all')
cubit.cmd('create block 1')
cubit.cmd('create block 2')
cubit.cmd('create block 3')
cubit.cmd('block 1 name "copp"')
cubit.cmd('block 1 name "copper"')
cubit.cmd('block 2 name "cucrzr"')
cubit.cmd('block 3 name "tungsten"')
cubit.cmd('Block 3 Volume 3 Volume 6 Volume 5 Volume 4 ')
cubit.cmd('Block 2 Volume 1 Volume 9 Volume 8 Volume 7 ')
cubit.cmd('Block 1 Volume 12 Volume 2 Volume 10 Volume 11 ')
cubit.cmd('create sideset 4')
cubit.cmd('create sideset 5')
cubit.cmd('create sideset 6')
cubit.cmd('sideset 4 name "heat_flux"')
cubit.cmd('sideset 5 name "htc"')
cubit.cmd('sideset 6 name "fixed_bc"')
cubit.cmd('Sideset 4 Surface 29 Surface 18 ')
cubit.cmd('Sideset 5 Surface 28 Surface 19 ')
cubit.cmd('Sideset 6 Surface 72 Surface 82 Surface 70 Surface 80 ')
cubit.cmd('set uspline vol all deg 2 cont 1')
cubit.cmd('build uspline vol all as 1')
cubit.cmd('fit uspline 1')

Thanks

makeclean

#2

@makeclean – right before you build uspline vol all as 1 run the command: build uspline crease group.

image
image1232×528 16.8 KB

Essentially this command evaluates the ACIS geometry, looking for “creases” in the BREP and then “flags” them to be creased in the U-spline. Long term plan is to streamline a lot of the U-spline stuff, you’re getting in early (a good thing!) when the “low-level” commands are still taking shape.

I’ve just noticed that we haven’t explicitly documented this command, so we’ll get on that right away. For now, the best documentation of the command is here

#3

@makeclean – never mind the above… I just realized this is a volume not a surface (I read it as “volume” but saw your screenshot and interpreted it as a surface).

The primary issue here is probably that you have an older version of Coreform Cubit. This creasing should be handled automatically in our latest development builds. Try downloading a latest development build and retrying.

#4

Smashing, I’ll give that a bash :slight_smile:

#5

Yeppers, using Cubit 2022.9 RC build did the trick, thanks @gvernon!