Whole project recomputes if touched

[jacksmailer]

I have a project where I am designing a wing of an RC plane. Hundreds of steps.

For some reason now I can't touch the project. If I ask for example to add a new sketch or construction plane the project starts computing from the beginning and because there are many body removal steps it just removes the wrong bodies and fails.

What is going on?

[jeff_strater]

we would need to see the model to tell more.  It is likely a problem with just this design, as we have not seen these symptoms in any sort of general way.  Can't really recommend a way around it without seeing the model.  Thanks.

[jacksmailer]

How can I send you the design? Would not want to make it public.

Thx

[jeff_strater]

If you have a commercial license, you can "Share Public Link":

If not, then the only way is to export the model as a "Fusion Archive":

This will result in either an F3D or F3Z (if your design uses external components) on your local machine.  Then, since you don't want to attach it here publicly, the usual way is to use some public file-sharing service like DropBox, upload the file there, then send me a Private Message with the location of that file.

Thanks!

[crueby1]

May or may not be related on this project, recently I've come across a case that makes it happen though:

I did a project at full size, then resized all the components to make a version suitable for making 2D plans for a scale model. If I make ANY changes after the scaling operation in the timeline, it recomputes the entire timeline, usually coming up with errors as the original poster describes. If I back the timeline up one step to just before the scaling operation, make my changes, then go forward to end of the timeline again, its fine. The changes can be as minor as adding a box object, does not need to involve changing anything existing or editting a sketch - just adding a box to the model causes the recompute.

Sorry if this is not related!

Chris

[jacksmailer]

Sounds exactly like the behaviour I'm experiencing!

[jeff_strater]

I was not able to reproduce this.  See the attached model.  The last fillet before the scale takes minutes to compute.  If I add a sketch after the scale, I do not see that fillet recompute.  So, if you have models which show this, again, we'd be interested in seeing them.

[jacksmailer]

PM Sent. Let me know if you get access to the file

[jeff_strater]

yes, I did, thanks.  And I see the problem that you reported, but it may take the team some time to find out the root cause.  I did notice that this seems to be a one-time thing.  Once the model has computed, it does not seem to show the compute for any subsequent operations.

I did not investigate the failures - I am not sure if they are valid failures based on some change or what.

A last-ditch approach would be to remove design history for the part of this design that is done (if you are happy with it and if you don't need to edit it further), then re-enable history for the rest of the design.

[jeff_strater]

the Fusion bug for this is FUS-101721

Another possibility:  If you try opening earlier versions, do they all have this problem?  If not, you can back up to an earlier version that is stable, and only lose the work between that version and the current one.

[crueby1]

Ah - now that the forum is back open, I'll post the files I have about this bug. Attached is a copy of one of the projects I have that show it, its easy to reproduce.

Also, two screencasts based on that project. In the first one, I tried to add a cube shape to the end, and it recomputes everything, generating a lot of errors:

https://autode.sk/3JHe4cx

and a second one, where I try to add a cube thats not in connected to anything in the project, not even in the same component, and it also recomputes everything, with all the errors:

https://autode.sk/3iEzoTS

Now, I think this is showing two bugs:

1) doing the recompute for no good reason after a scale operation, which in a larger project gets annoying

2) generating lots of errors in the recompute. This is really more severe of a bug, since it shows that the timeline is not capturing all the data it needs along the way. A user should be able to traverse back and forth along the timeline at will, and it should work cleanly. Otherwise the timeline becomes useless, and it is such a powerful tool at the heart of the feature set! I never 'delete' a body, since it warns of these kinds of problems, but I do use 'remove' along the way to get rid of un-needed bodies, which should be okay.

In your earlier reply, you mention that the recompute seems to be a one-time thing - well, with all the errors, getting past that one time is a major issue! And deleting the history COULD get me past the problem, it means no going back and changing anything earlier in the timeline, a last-ditch option as you say, not a good thing.

[jacksmailer]

I also only remove bodies instead of deleting.

I 

The problem is that when you split a body against another generating many new bodies, which are numbered by the software, then you recompute the new bodies get assigned new numbers, which breaks all the references.

I decided to bite the bullet, recompile, roll back the timeline and fix the errors manually. I've had to do this several times which is very annoying and time consuming

[crueby1]

Interesting - sounds like at least one case where the data in the timeline is not kept properly, there are probably others contributing to this bug.

[jeffmnc]

It has been my experience that Fusion 360 ALWAYS recomputes the 3d models, IFF you have created Bodies, when you change any sketch in any way. This has been the case with me for years and it becomes a problem on every major project but never on small projects. It will take a lot to convince me this a design-specific problem, or a bug -- it is quite obviously programmed into Fusion 360.

The only way I have found to stop it is to go in the lower right hand corner and use the menu to stop it from capturing the design history for the model.

Autodesk, please program in a button to turn off automatic recompute and a button to do a manual recompute. As being forced to give up the design history is crappy programming.