Problem with custom Operator fbx file after update to FS 17.2.1

[MBJEBZSRG]

[ FlexSim 17.2.1 ]

After updating to Flexsim 17.2.1 some of my custom operators no longer function.

I have created custom fbx for an operator and when I create a new Flexsim operator in Flexsim 17.1.6 and replace his fbx file with my custom operator I can open the animation clip editor and see the correct animations. In this case my animation sequence is 27.3 seconds long.

When I do the same thing in Flexsim 17.2.1 the animations seem broken and the sequence is only 10.0 seconds long. I have tested other custom operators that have shorter animation sequences similar to the standard Flexsim Operator and they seem to work. Only the one with the extended animations seems broken. Perhaps @phil.bobo can figure out why?

I have attached the FoodWorker.fbx file which is the one with the problem along with a HardHatter.fbx that seems to still work.

[philboboADSK · Accepted solution]

In 17.2, we updated the Assimp library from version 3.1.1 to 3.3.1. This update appears to have introduced this issue. The shape is coming in from the library with a shorter duration.

This appears to have been caused by a bug in Assimp, which has been recently fixed, and we built 17.2.1 against a version of Assimp between when the bug was introduced and when it was fixed.

The "bug" might actually have been a bug fix though. I think they changed it so that the animation duration is being read directly from the file instead of calculating the animation duration based on the location of the keyframes.

In 3ds Max, you can adjust the animation duration directly, independent of the frames:

Try adjusting the animation duration of this file and re-exporting it from 3ds Max. Let me know whether that fixes this shape's animation duration in FlexSim 17.2. (I would test it myself, but this shape seems to be made with a newer version of 3ds Max, and it wasn't exporting in the version I was using.) This might be a workaround for now.

I will also add a case to the dev list to update Assimp to see if that fixes this issue more completely.

[MBJEBZSRG]

That seemed to do it. Thanks Phil, you da man as always.

EDIT: One important thing to note however is that when you import your FBX operator into 3DSMax and change the time you have to re-export it to a new filename. If you just overwrite the existing one it wont update the time. Very wierd! But after a time I found out that if I export it to a new file, delete the old one and then rename the new file, it all works out.