Karamba and Octopus (Karamba may be causing octopus to crash?)

The following is a cross post with the karamba forum:
Hi all,

Hope everything is going good for you today! I’ve got a little problem I wouldn’t mind some help with (most likely a karamba staff job!)

The issue

I’m having a bit of an issue with karamba and octopus - with karamba causing octopus to crash when running (I believe).

I happen to have visual studio installed; and it reports the following error once it crashes:

“Unhandled exception at 0x00007FF9ADB520B0 (karamba.dll) in Rhino.exe: Fatal program exit requested. occurred”

Attached is the definition file with baked geometry if this helps.
01_Singleblock_Baked.gh (128.6 KB)
I am currently running Rhino 6 with the latest karamba build.

Details

I aim to create a parametric bridge model - optimising weight and deflection (structural) as well as proximity of 3 movable loads (architectural). The geometry creation is a bit complicated, however I do not think this can ever fail; as I have stress tested this.

The setup for octopus is as follows:

  • Inputs (for octopus and the parametric model)
  • Geom. creation (parametric model)
  • Karamba analysis
  • Outputs (one is non-karamba, the other two are karamba based)

After an arbitrary number of phenotypes generated (usually around 200), Rhino quits constantly.

I have double checked the following:

  • Octopus can run with just the inputs (a fake output is created to allow for octopus to run). It does not crash here.
  • Octopus can run with the inputs and the non-karamba outputs. It does not crash here
  • Octopus cannot run with the inputs and the karamba outputs. It crashes here
  • Octopus cannot run with the inputs and all outputs. It crashes here

I have also checked the following:

  • Geometry generation is built ruggedly (by setting parameter limits appropriately & testing extreme scenarios)
  • Octopus never receives any value to make it quit (see if statement at the end of karamba parameters)

Any help is appreciated, as I’m currently on a deadline for my thesis on this!

Best,

Alex

Hi Alex,

Have you solved the problem?
I am having similar issues as you had:

Best,
Mikołaj

Hello Mikolaj,

it seems like your statical system is not stable. When using truss elements only, make sure to support them against out-of-plane- movements by corresponding supports. Use the ‘Eigenmodes’-component to visualize the rigid body modes (see the manual for details).

Best,

Clemens

If anyone has come across a similar issue just jump to that topic:
https://www.grasshopper3d.com/group/karamba3d/forum/topics/karamba-user-problems?commentId=2985220%3AComment%3A1988053&xg_source=msg_com_gr_forum

(Karamba3D forum > Karamba User Problems > page 15)

Hello Mikolaj,

does the system crash similarly when you use Galapagos instead of Octopus?

Did you check whether the system runs out of memory during optimization?

Try to use the divide an conquer strategy: reduce the structural model in steps until the problem does not occur any morem, then divide the last steps in substeps and so on until you can locate the problem.

Best,

Clemens