X Particles "Render Geometry" doesn't work when use GROUPS Tweet

[rjohn]

Hi, I was just asking if you were working on the problem. If not, I think you should change the Octane manual or describe the behavior there. Apart from that, you can find a small, very simple XParticles project with 7 emitters in the attachment. Under Octane 2021 it is not possible to render this with RTX-on - after (long) experimenting I came to the conclusion that you have to set RTX to off. Of course I will report this to Otoy via the bug report - just for your info .

[aoktar]

I was asking to know what's the problem for your opinion? It's possible to use the groups, for my opinion usage needs some attention because it takes the numbering from the ordering in list. That's all!

[rudybertazzo]

The problem is that in Octane 2020 you could just drop any objects in the "Particle Rendering" tab and they will all render normally, regardless of the "Group Number" of the X-Particles group.

In 2021 this is no longer possibile, since it renders ONLY the object corresponding to the Group Number in a list, as you can see in the attached image.
So if the Group Number is 2, and you have two objects in the Particle Rendering tab, it will only render the second object, and not both.
Likewise, if the Group Number is 2 and you have only one object Particle Rendering tab, it will render none.

This behavior leads to two major issue:

1- You can no longer render multiple objects in the same emitter using the Octane ObjectTab

2- More importantly, if you have several X-Particles Groups, you have to put in each Octane ObjectTab a number of objects corresponding to the X-Particles Group of that Emitter.
This is EXTREMELY frustrating, as it's really a pain to render objects when you have multiple X-Particles Groups.

This is obviously a new issue, as in Octane 2020 it didn't work like that. Are there any plans to fix it?

Thanks.

[aoktar]

@rudybertazzo
adding an option as use_group_numbers that should fix the problems.

Also, I see that your feedbacks is not fully correct after some investigations. You can still render multiple objects with object tag. Also you can still render one object if you close the "groups to use" parameter in xpEmitter. I'll make some revisions by adding "use_group_numbers" under particle rendering. And it will ignore group rendering if you just one object in tag. Otherwise you'll still have to put objects as group numbers to match the group IDs. Because there's not any UI helper to assign group IDs for assignments.

Better to share a few scenes and I'll show you what's wrong in the setups.

[rudybertazzo]

Hi Aoktar, thank you for your feedback.

Yes, you can still render multiple objects using the Object Tag, but only if you're not using X-Particles Groups.
However, the issue here is specifically when you are using Groups.

I'm not quite sure what you mean by "closing the groups to use parameter" in the xpEmitter, but any solution that disable Groups won't solve the issue, because it defies the purpose of using Groups in particle simulations.

To summarize:
1. If you don't use X-Particles Groups, you can render how many objects you want in the Particle Rendering tab of the Octane ObjectTab.
2. If you do use X-Particles Group, it will only render the object in the Particle Rendering list corresponding to the Group Number.

Octane 2020 used to work as the first option, regardless of whether you were using Groups or not.

In the 2021 version, when using Groups you can't render more than one objects per emitter, and more importantly it's a pain to setup when you have multiple Emitters and multiple Groups.

Please see the attached images showing different cases. The first one is how it used to work with Groups in Octane 2020.

Thanks

[aoktar]

@@rudybertazzo
it will read the groupID and make the assignment when they have group numbers. Why don't you disable group items from this list? This will make groupID=-1 and will let you render multiple objects. What avoid it to do?

[rudybertazzo]

@Aoktar because disabling group items from the "Groups to Use" list, as you suggested, it's like disabling or deleting Groups entirely, therefore is not a solution.

If you disable a Group from that list, you're just telling the xpEmitter NOT to use that Group, which defies the purpose of using Groups at all.
For example, if you have a modifier that affects all the xpEmitters assigned to a particular Group, and you disable that Group from the "Groups to Use" list in the xpEmitter, that xpEmitter won't be affected by that modifier anymore.

Can I ask why in Octane 2020 you could just render whatever objects you like in the OctaneObject Tag regardless of Groups, but not in 2021?
Unfortunately this is a big issue for heavy X-Particles users like myself.

Thanks again for your time and fast response.

[aoktar]

Can I ask why in Octane 2020 you could just render whatever objects you like in the OctaneObject Tag regardless of Groups, but not in 2021?
Unfortunately this is a big issue for heavy X-Particles users like myself.

Because in 2020 we didn't have groupID matching for the clones, now 2021/2022 is checking the groupIDs for clones and using group assign if groupID is available. As I said that problem is there's not an option to don't use grouping feature. I'm adding it

[rudybertazzo]

Thanks for the explanation, as for the solution that's great to hear! Guess I'll stick to older version till that option will be available.

[aoktar]

Thanks for the explanation, as for the solution that's great to hear! Guess I'll stick to older version till that option will be available.

Please check this test build and give the feedbacks
https://render.otoy.com/customerdownloa ... st-win.rar