FDTD IDE Crashed when trying partial cylinder as ellipsoid

amnonjwamnonjw Member Posts: 9


I'm using the FDTD IDE 2021 R2.

When I use the Partial Cylinder" object - If I set the option "make ellipsoid" as true - the application crashes.

This happens if I use the GUI window of the options, and also if I run the command

set("make ellipsoid",true);

Attached fsp file can be used to reproduce the issue.

Also I remind you of another issue I reported: with partial ring object - If I set "make ellipsoid" - the visual render moves the object into incorrect location.


  • gsungsun Posts: 1,692Ansys Employee

    Just let you know that, the previous incorrect location bug ha been fixed and the fix will be in the coming new release.

    As for the crash, I tested the partial ring with glass, Ag and Au materials, and did not find the crash:

    It might be related to material. Please restart your computer, and redo the project file again.

  • amnonjwamnonjw Posts: 34Member


    Good to know you fixed the issue with the rendering.

    As for the crash issue - on my system it's independent of the material. Please check in your verification that you made a partial cylinder - that is a partial ring with both "inner radius" values = 0 for an ellipsoid.

    If the two issues are related, then perhaps the correction of the rendering bug also prevents the crashing.

  • gsungsun Posts: 1,692Ansys Employee

    Unfortunately, the ring is not supposed to have inner radius 0. If you want to have a cylinder, please use circle object.

  • amnonjwamnonjw Posts: 34Member


    The object named "Partial Cylinder" is part of Lumerical library made by your team. It looks like "partial cylinder" is an object that is based on a "ring", but conceptually a partial cylinder can be made to have an ellipsoid cross section and your GUI currently allow me to ask for it. If you decide now that this is not a shape that the IDE can manage - then remove the check box "make ellipsoid" for it specifically.

    But it looks to me that with a few code adjustments to the basic ring model should prevent the IDE from crashing when generating a "ring with inner radius of 0".

  • gsungsun Posts: 1,692Ansys Employee
    edited December 2021

    Please note that you cannot set  inner radius of 0 as it does not work this way. The software could be improved but since there is method to avoid this issue, due to heavy projects ongoing this may not be done in a foreseeing future. Even though the structure allows you to set  inner radius of 0, please do not use it if it causes crashing.

  • amnonjwamnonjw Posts: 34Member

    Again - I'm not setting "inner radius" to be 0. It's Lumerical's object library that creates the object "Partial Cylinder" with "inner radius" set to 0.

    What i'm doing is setting it to be elliptical.

  • gsungsun Posts: 1,692Ansys Employee

    It works well in the new version.

  • amnonjwamnonjw Posts: 34Member

    The configuration in the image works fine in version 2021-R2.5/

    So this comes down to having a ring element, marked as an ellipsoid with both inner radius values set to 0. This is the default configuration when I add "partial cylinder" to the layout and mark it as an ellipsoid.

    I suggest, to make this fool proof, that the IDE will make a sanity check for both inner radius values not to be 0 together when using "make ellipsoid".

  • gsungsun Posts: 1,692Ansys Employee
    edited January 10

    May I know what is your OS version? what are the parameters you set? please provide the 4 parameters.

    I tested the partial ring and partial cylinder, and both work well on my windows computer:

    Only the partial cylinder has a default inner radius =0. The ring has a 0.1um. I even used 0 um radius and it works fine:

  • amnonjwamnonjw Posts: 34Member


    I verified this again on the IDE of R2.5 with a new file - You are correct and now there's no crashing at all.

    Good job

Sign In or Register to comment.