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Strange spots on 2D surface

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Old   July 30, 2020, 05:22
Default Strange spots on 2D surface
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Alessandro Donadeo
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Hi everyone.
As you can see from the figure, by importing my 2D simulation from STAR CCM+ into Tecplot (.case format) you notice strange "spots" on the surface.
I can't understand what it is due to.
NB: I used a polyhedral mesh.

Thanks.
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File Type: jpg WhatsApp Image 2020-07-29 at 14.00.07.jpg (40.6 KB, 3 views)
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Old   July 31, 2020, 12:11
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If this is truly a 2D simulation a non-grid variable is likely being assigned to your z axis. Either swap to 2D Cartesian plot type from the plot sidebar. or ensure that a variable which is constant is assigned to the Z axis by going into Plot> Assign XYZ if something other than Z is assigned you can create a z variable by going into data>Alter> specify equations and enter '{Z}=0' and then use that in Plot>Assign XYZ as your z variable.
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Old   July 31, 2020, 12:42
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Alessandro Donadeo
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Quote:
Originally Posted by novedevon View Post
If this is truly a 2D simulation a non-grid variable is likely being assigned to your z axis. Either swap to 2D Cartesian plot type from the plot sidebar. or ensure that a variable which is constant is assigned to the Z axis by going into Plot> Assign XYZ if something other than Z is assigned you can create a z variable by going into data>Alter> specify equations and enter '{Z}=0' and then use that in Plot>Assign XYZ as your z variable.
Thanks for reply!

Moving on to 2D Cartesian the problem disappears.
However in 3D Cartesian no. The variable associated with the Z axis was already inserted correctly; also creating a new variable, initializing it to zero and using it in the "Assign XYZ" dialog the spots remain.

I have attached the .zip file and also some images that make it clear how the spots I think are cells of the mesh.

I noticed that the problem is present only when the Shade toggle is activated.
The problem is present only Lighting effect is activated.

Thank you!
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File Type: jpg zoom con mesh.jpg (199.6 KB, 3 views)
File Type: jpg zoom no mesh.JPG (37.1 KB, 4 views)
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File Type: zip ZAU.zip (490 Bytes, 1 views)

Last edited by AlphaDelta; July 31, 2020 at 13:08. Reason: Mistake
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Old   July 31, 2020, 13:23
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Thanks for the more detailed screenshots, in them it looks like this is actually a known bug with Tecplot's shading layer.

The current recommended work around is to switch to paneled shading (it only effects Gouraud shading) for the zones which are effected. To do this go into Zone Style> Effects Tab> Lighting Effects> Paneled.

(Note, Ensight case files need the supporting files to load into Tecplot, if you could send the full set to support@tecplot.com that would be helpful when fixing the bug)

Devon
Tecplot Product Manager
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File Type: png paneled.png (11.2 KB, 2 views)
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