SimScale CAE Forum

:( Geometry and Meshing 'bugs' from native RHINO file


#1

Is this simply a geometry display ‘bug’.

The geometry shows a curved face (not curved in Rhino):


BUT the mesh from that geometry is straight again:


Issues using Cyclic Symmetry
#2

Hi Dale!

You substituted the models, is that correct? Want to have a look at this before I report it.

Edit: Got it now :slight_smile:

Best,

Jousef


#3

What you mean, first image is of geometry and 2nd is a mesh made from that geometry.


#4

Oh-oh, it now looks like more than a geometry display bug …

Here is a bent mesh too:

And the geometry shows as bent in SimScale UX , but different faces are bent:

BUT, in RHINO the bent faces are ALL planar faces:

Now we really need some experts involved quickly in case the mesh was really generated like that :sob:

EDIT: Another data point.
I tried to run a simulation on the mesh using cyclic symmetry.
I had to stop the simulation run after being stuck at 4% for ~25 minutes.
The simulation issue is not likely caused by this ‘geometry and mesh display bug’ but IT COULD BE, so here is the stalled Simulation Run

EDIT #2 And, finally here is proof that it is not just a ‘display’ issue.

I downloaded the results of a cancelled Run 1 using the above mesh. I then opened the results in ParaView, this Paraview image says it all:

I have edited this topic name accordingly :sob:


Issues using Cyclic Symmetry
#5

Hey Dale,

Have reported the issue and awaiting a response from my colleagues :slight_smile:

Best,

Jousef


#6

Hi @DaleKramer,

I downloaded your file, imported into Onshape and it looked just fine. I then imported teh Onshape file into Simscale and it looked good. Somehow, Simscale is having problems reading teh original file correctly.

Christopher


#7

@cjquijano Please see the Edit #2 I made to Post 4.

Thanks for confirming that the ‘bug’ appears to be related to the way SimScale interprets the native RHINO files which I unfortunately have used for all my SimScaling :sob:

Still doesn’t explain why we have so far in Post 1:

  1. Good geometry in RHINO
  2. Bad geometry depiction in SimScale
  3. Good mesh generation in SimScale

But in Post 4 we have:

  1. Good geometry in RHINO
  2. Bad geometry depiction in SimScale.
  3. Bad, but different, mesh generation in SimScale
  4. Bad mesh from a sim results as seen by ParaView, (this bad mesh in ParaView is the same as bad mesh in SimScale)

This may have far reaching implications for all the projects, their meshes and sim results which I have ever created with SimScale :sob: :sob: :sob:


#8

Hi @DaleKramer,

I am having a hard time visualizing the second image in Post 1 but a course mesh could hide issues with the geometry. Hopefully Simscale will enlighten us on Monday. :grinning:


#9

That 2nd image in Post #1 was not to show mesh quality, just to show that the incorrect curve of the right side lowest face in the geometry was not transferred as curved in the mesh that was generated from it (since all mesh faces are planar) …


#10

Bump … any progress from SimScale side to report ?


#11

Not yet Dale :slight_smile: Will push a little bit.

Best,

Jousef