Edit Instances mode - loosing most of changes if reopen the scene

[brr]

Hello devs,

I have come across another issue with Scatter Edit Instances Mode: when I make final changes in this mode, save the scene, and then load it again, a lot of changes are lost. Scaled objects remain intact, but deleted and moved objects are restored (often in different positions) after reloading the scene. This makes the Edit Instances mode completely unusable for precise projects. It becomes problematic if you later need to re-render certain elements or if you simply need to close Max but maintain consistency.

Corona 9 HF3
Scatter version:
2 (Hotfix 4), build timestamp: Apr 25 2023 16:59:51
(c) Chaos Czech a.s., 2019-2022


Please look at my attachments:
01-scattered and instanced edited.jpg
02-after reloading  the scene.jpg

Scene:
ChaosScatter inconsistency after edit instances.max

Hope you can reproduce it and fix it soon.
Best Regards

UPDATE:
Just looked at trello roadmap, it seems like Corona10 comes with Scatter v3 and maybe this bug got fixed.
Is there a way to get Scatter Installer independently to update only the scatter ? I need to stick with corona 9 for a while...

[romullus]

I got the same behaviour in Max 2024, Corona 10 HF1, Scatter 3 however after some digging, i found that this is related to scatter's avoid collision setting. If avoid collision is off, then edit instances behaves predictably and edits stays consistent between multiple sessions. You need to take into account that originally in your scene there is 1 000 teapots being scattered, but most of them are culled off because of avoid collision. After you edit some instances and remove them, any vacant place can be repopulated by culled instances. I think this repopulation should happen either in the process of editing, or as soon as you quit editing mode, but for some reason it only happens when you reload the scene. It's likely a bug, but not what probably you originally was thinking.

[brr]

Hello romullus,

Yes, you are right. Turning off "avoid collisions" resolves this issue. However, without this option turned on, working with Scatter becomes very messy—no matter how many items you set in the "max limit," collisions always seem to occur.
In most cases, it can not be like workaround or compromise, because you end up needing to delete and move a significant amount of elements to achieve the desired look. It simply kills the oportunity of being Scatter so parametric.

As demonstrated in various demo videos, the "edit instances" feature must solve "final touch" problem. It should allow for minor adjustments, with the capability to "remember" all the actions between 3ds Max sessions. Otherwise, its usability is very limited...

Best regards

[romullus]

Just to be clear - i'm not saying that's not bug, because quite clearly it is, i'm saying that if you edit instances with avoid collisions being activated, it's not very reasonable to expect that your edits will be the only thing that's changed in the scatter. If you look closer at your after edit and after reload scenes, then you should notice that your edited instances are keeping their changes and the only difference is that there are new instances added after reload. The bug is that those new instances should be added in the same session when you made the edits and not after scene reload.

If you want to have collision free instances, you must accept the fact that your arbitrary instance edits will have further consequences on the scatter. Perhaps it's worth considering to request "freeze instances distribution" option in the scatter, so when user is more or less satisfied with parametric instances placement, he could lock their position and make individual adjustments with full confidence that nothing else will change without his consent.

[Avi]

Hi,

We were able to reproduce this issue on our end and we have logged this in our system to be further investigated by our devs. We will let you know if there are any updates on this.

(Internal ID=1174880023)

[brr]

Hi,

We were able to reproduce this issue on our end and we have logged this in our system to be further investigated by our devs. We will let you know if there are any updates on this.

(Internal ID=1174880023)

Hello Avi,
Thank you for the information. I hope it will be fixed or improved soon.

Just to be clear - i'm not saying that's not bug, because quite clearly it is, i'm saying that if you edit instances with avoid collisions being activated, it's not very reasonable to expect that your edits will be the only thing that's changed in the scatter. If you look closer at your after edit and after reload scenes, then you should notice that your edited instances are keeping their changes and the only difference is that there are new instances added after reload. The bug is that those new instances should be added in the same session when you made the edits and not after scene reload.

If you want to have collision free instances, you must accept the fact that your arbitrary instance edits will have further consequences on the scatter. Perhaps it's worth considering to request "freeze instances distribution" option in the scatter, so when user is more or less satisfied with parametric instances placement, he could lock their position and make individual adjustments with full confidence that nothing else will change without his consent.

Hello Romullus,
I understand what you mean, but actually, I do not understand for what situations the current behavior even with instantly adding instances in the same session would be useful. That's why I personally consider this to be a bug/working wrong, as it works in opposite to the option description.

[brr]

Hello Devs,

Recently, we received corona-11-3dsmax-daily-2023-09-06.exe, with Changelog information:

"When an instance is translated directly by the user, new instances no longer appear at its original location when collision avoidance is enabled."

If I understand this correctly, has this issue already been resolved?

Thanks in advance.

[Avi]

Hi,

That is correct, it is fixed and is available on the latest daily build which you can get from here: https://forum.corona-renderer.com/index.php?topic=40442.0

[brr]

Hi,

That is correct, it is fixed and is available on the latest daily build which you can get from here: https://forum.corona-renderer.com/index.php?topic=40442.0

Hello Avi,
great news!

Thanks, Corona-Team !

[alexyork]

Would the devs consider pretty clear bug fixes like this as something you can roll out into a Corona 10 hotfix? New features and tools certainly make total sense pushing into dailies, but if something's found to be a bug and doesn't conflict/require anything new from a daily/new core then it would be a huge benefit bringing it to the current version of Corona instead of having to push into dailies/full new version (which takes time to be released, tested, HF released etc.). It'll be a looong time before we're moving to Corona 11 final + HF, presumably, since C10's only just been released.