topic Betreff: Problems with driving constraints in posreps in Inventor Forum

Problems with driving constraints in posreps

WHolzwarth — Tue, 18 Oct 2016 21:37:13 GMT

Has anyone else seen this in complex movements?

After switching to posreps, many parts, that should be without motion, are moving back and forth.

I'll agree, that it's far away from nothing. But that's not all, and could be better.

Mp4 file is attached. 2016 files can be provided, if you're interested.

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Wed, 19 Oct 2016 10:38:34 GMT

Got it now.

Some of the gears can rotate versus the shafts; I've now placed them not in flexible shafts, but in the top-level assembly.

Another issue was better constraining: No free DOFs, but no over-constraining is best.

Betreff: Problems with driving constraints in posreps

WHolzwarth — Wed, 19 Oct 2016 21:38:22 GMT

Hmm. This whole stuff needs improvement. Triangles instead of +/- symbols in Browser don't really help with that.

I could solve the problems with the gearing at the left. But have a look, what happens with switching to different gearing settings at the crane beam.

It's close to crazy

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Thu, 20 Oct 2016 20:24:04 GMT

I've struggled the whole day with that. No real problem for retired persons

I could solve the flipping of the crane beam by temporarily suppressing rotational/transitional movements of the electric cylinders

What do I suspect?

- Rotational joints seem to be more critical in posreps than insert constraints. Sometimes rotational joints get angular settings induced in posreps. I don't know, where they are coming from

- If a main assembly is in a LOD, there's a good chance for locking all setups of driven constraints

- Same behavior seems to caused by a constraint from rotational input to to linear output

It's a challenge for me. Can you do it better, AutoDesk?

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Fri, 21 Oct 2016 08:49:39 GMT

Another issue can be seen in this video (27 MB).

As can be watched at about 50% time, the worm set can be moved ok by mouse. But no movement is done, when driving the total constraint train.

The rotational/translational constraints of the electric cylinders beneath the beam are suppressed. If unsuppressed, no movement at all is possible.

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Sat, 29 Oct 2016 16:53:10 GMT

I'm still struggling with this crane. Lots of problems need to be solved or worked around.

Here's another video, recorded with Camtasia from a Studio animation. The red clutch is well constrained, but jumps suddenly at the end of a changing posrep.

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Sun, 30 Oct 2016 09:03:57 GMT

This morning I saw:

Report done, and fingers crossed ...

Betreff: Problems with driving constraints in posreps

WHolzwarth — Sun, 30 Oct 2016 23:31:47 GMT

Late in the evening I have good news, and bad news.

Good news:
- I could run through the first steps of a Studio animation.

Bad news:

- Tasks like this can only be done with Studio. Driving by constraints is locked suddenly by unknown causes, and Dynamic Simulation can't handle that either.

- Even with Studio, I had to freeze the crane subs into a derived part.

- But sad to see, that some part colors got lost in the derived part. I need to look for that, it seems to be caused by color overrides in the parts

- Decals don't appear in derived parts. Well, I could place them again there

- Animated posreps in Studio are no way to go, because some envolved parts are doing uncontrolled jumps

- Rotational/Translational constraints don't work well in many cases

- All parts must be fully constrained, except their needed movements

But now the best:

Trying to create a video, only a small part of the screen was recorded. See picture of the normal screen, when animation runs in Studio. Kamera1 is ok there in view size, but decreases in recording.

And now let's have a look at the video screenshot:

Now it's time for a break. I'm not amused.

Betreff: Problems with driving constraints in posreps

WHolzwarth — Wed, 09 Nov 2016 22:37:17 GMT

Time goes by. I started another animation, but problems with camera settings and recordings are still present.

- AVI records are crashing

- Large WMF records are crashing the same

- Only image recording of 625 images was possible (25 seconds with 25 images per second). Combining was done with Windows MovieMaker

But: Even I could place some camera settings in Studio timeline-run, they were broken with video recording. I only succeeded in recording a fixed view. Result is attached.

This was no easy task.

- Lots of switching between Studio and Assembly environment were needed, for resetting startup conditions in Studio

- Time and start-end position changes in Studio are tricky

Well, I could solve these issues by lots of trials and errors. But now I'm stuck again with camera settings. Only garbage comes out.

That's hidden in the fixed view record:

- Left door of cabin closes

- 4 outrigger feet move up, together with gear movement

- 4 outrigger feet move inward, together with gear movement

- Crane moves along path, returns and comes back

- While this movement, motor pistons, crank, and differential gearing are moving, too

- Wheels are rotating and changing their steering angles in the turn

This could be much better, with more options in camera setting. I suspect, that this is poor.

But perhaps it's only my lack of skill. I can provide a file set, if anyone likes to improve that result.

Walter

Betreff: Problems with driving constraints in posreps

LishuangLu — Thu, 10 Nov 2016 04:37:49 GMT

Hi Walter,

The video made by you is fantastic. Thanks a lot for playing with Studio and making such wonderful videos!

And based on your usage in studio, there are several issues which need to be investigated by us. Do you mind working with us to investigate and improve them one by one?

Since these issues are related with large assemblies, it will request more time for investigation, reproducing and fixing, please allow some delay for the fix or workaround.

Can you first share the dataset with me? And you can contact me with email directly. Lishuang.lu@autodesk.com

Thanks,

-Lisa

Betreff: Problems with driving constraints in posreps

WHolzwarth — Thu, 10 Nov 2016 09:37:38 GMT

Good morning, Lisa

Here's the link to a Zip in A360: http://a360.co/2fzWYzK

I've reduced the total size by only using the truck (no crane), but all movements are still there. I didn't try new camera settings by now, but I'll make another attempt later.

At first try this:

- Open the main file and switch to Studio environment. Add all shadows. This must be done each and every time. Next run they are gone again. Same behavior is with shadow percentage, it's always coming back next time with 100%

- Perform a timeline run. It should move now the full period of 25 seconds

- Next, move it back from 25 seconds. It starts ok, but stops in the curve and locks. Nothing can be done

- So you'll need to end Studio and return to assembly environment. Now there's a good chance, that outriggers lost their position versus the chassis. Do that now: Switch all flexible pieds and mavoeuvres (8 instances) off and back on. Position is back after that, but the red cross is lighting. Do a Rebuild all for turning it off

- After that a 2nd timeline run should be possible. Now at 25 seconds, try to move time pointer back to start. No luck. Studio must be ended, procedure above

- Now you're ready for a 3rd run. Let's edit the Drive_me constraint in Studio. I've started with an initial distance from 10 mm to 1810 mm, now it's ending at 2600 mm. I only could get that result by gradually changes of 50 or 60 mm steps. These 2600 mm are near the end of path (Fahrweg.ipt); perhaps this file needs an extension for trying versus 2700 mm

- Next issue: Edit Lenkwellenwinkel (at 15 s). Change end angle from 120 to 150. You can't (The specified value could not be applied)

- Now move this in timeline to about 0,5 s. Change from 120 to 150 can be done. It took some time here for discovering

- Another behavior, perhaps it's my fault: Kurbelwellenwinkel is suppressed in assembly environment. Because of gearing ratio, it needs to move from 0 to -6600 deg during a timeline run. But this value seems to sum up with another run.

All of these problems could be worked around. But I'm whining and grumbling with these camera issues.

Let's hope for improvements

Walter

Betreff: Problems with driving constraints in posreps

WHolzwarth — Thu, 10 Nov 2016 14:16:51 GMT

Meanwhile I made a new attempt with the reduced file. This time camera moves were possible.

I completed it with crane, Mountain rambler and LEGO figure.

Heureka! See result.

Betreff: Problems with driving constraints in posreps

LishuangLu — Fri, 11 Nov 2016 12:42:38 GMT

Hi Walter,

Thanks for sharing the dataset with us! I can download it and open it in my side.

I tried your workflow, opening it in Inventor, then switch to Inventor Studio and play the animation, when the animation runs, I could not see anything changes in the view, and it pops up an error message "Model has failed to update for the current time. Please correct the animation definition." when the time runs to 2.2 s.

Do you know whether anything is missing by me?

Thanks,

-Lisa

Betreff: Problems with driving constraints in posreps

WHolzwarth — Fri, 11 Nov 2016 13:32:25 GMT

Hi Lisa,

I just downloaded the data from A360 to a new folder, but without creating another project.

Studio animation ran forward without error through the whole timeline.

My Playback interval in Animation options is set to 0.1s.

I'll use a new project now. Let's have a look.

Betreff: Problems with driving constraints in posreps

WHolzwarth — Fri, 11 Nov 2016 14:06:41 GMT

No stop using another project, too.

From 0 to 2.2s there's no movement, just for having a look. At 2.2 s the left door of the driver's cabin starts closing.

Betreff: Problems with driving constraints in posreps

Cris-Ideas — Fri, 11 Nov 2016 20:38:17 GMT

Hello Walter,

Nice assembly you have constructed. I see there was not much action from Autodesk for quite a log time since you have made your first posts.

I wish I had time to try with your assembly but this will not be possible. I am however very much interested what will be the outcome of Autodesk investigation.

From my experience I can only share some general remarks, which of course are not "advices for you" but rather points for development to take in to account :

1) flexibility and POS REP do not go together well, not at all

2) flexibility generally is an issue.

Cris.

Betreff: Problems with driving constraints in posreps

johnsonshiue — Tue, 22 Nov 2016 21:03:39 GMT

Hi Walter, This behavior has nothing to do with Inventor Studio. This is constraint behavior. I love to see the dataset but the files you shared on Box are incomplete. I am missing a few pieces. Could you try something real quick for me. For the flexible subassemblies in the assembly, try grounding the flexible subassemblies and then make sure all other components within the flexible sub are ungrounded. This trick helps remove the redundant DOF introduced by flexible sub. Please let me know what you find out. Many thanks!

Betreff: Problems with driving constraints in posreps

WHolzwarth — Tue, 22 Nov 2016 21:35:56 GMT

Hi Johnson, thanks for stepping in.

I spent several hours with this crane, and I did switching from flexible to non-flexible and back again not only once.

Tell me, what files are missing, and I'll send them to you.

Walter

Betreff: Problems with driving constraints in posreps

johnsonshiue — Tue, 22 Nov 2016 22:30:50 GMT

Hi Walter, The following part files are missing from the Chassis dataset. 3713-LtBluishGray.ipt #data.ipt 48989-LtBluishGray.ipt 32449-Yellow.ipt Many thanks!

Betreff: Problems with driving constraints in posreps

WHolzwarth — Tue, 22 Nov 2016 22:47:50 GMT

Missing files attached.

From what I've seen, both driving by constraint and Studio animation needs improvement.

Thumbs up. It's not easy.

Walter