Author Topic: Chaos Scatter feedback  (Read 16993 times)

2022-03-17, 10:31:13
Reply #15

GeorgeK

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I think that there's some problem with translation tab.
For example setting min 0cm and max 50cm on Z axis moves instanced objects just a little bit - like 0,5cm, definietly not 50cm.

Hi, can you please send us a reproduction scene of the issue you are reporting, (or if possible your current scatter setup)? I am afraid I wasn't able to reproduce this.
George Karampelas | chaos-corona.com
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2022-03-17, 10:33:47
Reply #16

maru

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Keep in mind that if Z translation is set to 0 - 50 cm, then the instances will be moved randomly in this range, so:
- a tiny number of instances will be moved 0cm (or almost 0cm)
- a tiny number of instances will be moved 50cm (or almost 50cm)
- a large number of instances will be moved somewhere between 0 and 50 cm; 25 cm on average
Marcin Miodek | chaos-corona.com
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2022-04-20, 19:51:59
Reply #17

romullus

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I have small request. Currently include/exclude splines are projected in world space only. Please consider to also add a local (object) space option. This would be very handy to define precise inclusion/exclusion areas on more complex terrains.
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2022-04-21, 16:22:07
Reply #18

aaouviz

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Hi,

Not sure if it's a bug or an intended feature, but if I use a closed spline (surrounding the edge of a surface I'm scattering on) as the exclude spline, the entire scatter doesn't work at all.

I doubt this is intended... seeing as there is no edge texture (like FP has) this is my best shot at having sharp edges for grass scattering (please let me know if I'm missing something and there is a better workflow).

Hope this is clear and replicable.
Nicolas Pratt
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https://www.instagram.com/anotherangle3d/

2022-04-21, 17:02:18
Reply #19

romullus

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I don't think that's a bug - if the spline is completely covering all the distribution are and you are using it as exclude, then obviously nothing will be scattered. Try to use spline as include, but don't expect that it will be somehow better for edges than normal scattering - it still uses distributed object's pivot to determine its placement.
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2022-04-22, 07:51:52
Reply #20

aaouviz

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But it's about distance from the spline, right?

So if I scatter on a square that's 5000x5000mm and a bordering closed spline around it as an exclude set to 100/150mm the WHOLE scatter shouldn't be disabled...

I think the proof is that if I break that same spline even by a tiny amount so it's not closed, the scatter works as expected...
Nicolas Pratt
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2022-04-22, 09:49:48
Reply #21

maru

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But it's about distance from the spline, right?

So if I scatter on a square that's 5000x5000mm and a bordering closed spline around it as an exclude set to 100/150mm the WHOLE scatter shouldn't be disabled...

I think the proof is that if I break that same spline even by a tiny amount so it's not closed, the scatter works as expected...

To me it sounds like the current behavior is expected, but maybe I am missing something. Could you share some screenshots / renders showing what exactly you are doing and why? That would greatly help us.

Other than that - maybe you can use the Corona Slicer Material for edge trimming? https://support.chaos.com/hc/en-us/articles/4956761514897-How-to-use-the-Corona-Slicer-Material
Marcin Miodek | chaos-corona.com
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2022-04-22, 10:40:01
Reply #22

Bjoershol

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Sounds like this is by design, you need to be able to use a closed spline while still being able to use distance on the outside of the spline. The solution would be to break the spline, unless I'm missing something. :)

2022-04-22, 10:44:33
Reply #23

romullus

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But it's about distance from the spline, right?

So if I scatter on a square that's 5000x5000mm and a bordering closed spline around it as an exclude set to 100/150mm the WHOLE scatter shouldn't be disabled...

I think the proof is that if I break that same spline even by a tiny amount so it's not closed, the scatter works as expected...

That's right, but the thing is, that near/far feathering radiates outside of closed spline, not inside, so if your spline is exactly bordering your distribution mesh, then no matter what you'll do, it will always exclude everything.

As for the splitting the spline - as soon as you do that, there's no longer an inside or outside and inclusion/exclusion will propagate from the spline in all directions.
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2022-04-22, 11:10:34
Reply #24

maru

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So to me it still sounds like expected behavior, but if we can make our users' lives easier, then why not? :)
I would still appreciate taking a look at what exactly the use case is so that we could report it to the devs. Thanks!
Another option is contacting us about this at https://support.chaos.com/hc/en-us/requests/new
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-04-22, 11:21:56
Reply #25

romullus

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So to me it still sounds like expected behavior, but if we can make our users' lives easier, then why not? :)

Maybe you could do that near and far would take negative values as well, then user could choose in which direction to extend inclusion exclusion area. The only downside to this, is that negative values would make no sense with open splines.
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2022-04-22, 11:40:18
Reply #26

aaouviz

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Ok,

Thanks for all the input.

I guess the main takeaway here, for me, and probably other users, is that the spline include/exclude works differently if it's closed or not. This is handy to know; If it's closed, it excludes everything inside the spline, but if it's open it excludes in a feather in both directions of the spline.

I think this double situational/conditional use is a bit confusing, personally, but can live with it :)

I guess the best case use of the closed spline is if the user wants to make 'islands' of no/only scatter. Understandable and useful.

Screenshots attached to show my 3 test findings. I no longer have a particular beef with the workflow, but perhaps other users can chime in?

----

As for the clipping material for clean grass edge surfaces... ugh, I don't think this is a great scenario either. When using Corona scatter my previous best option was to use a shelled version of the scatter surface to act as a distance object for the opacity of the grass. This new suggested workflow isn't much of an improvement - I still have to use a separate object. If I edit the scatter surface this breaks the shelled version of it (I know, I know, it can be a referenced instance, but this isn't always clean/possible).

Is there a better workflow I'm unaware of for clean grass edges?

Thanks again.
Nicolas Pratt
Another Angle 3D
https://www.instagram.com/anotherangle3d/

2022-04-22, 11:41:53
Reply #27

aaouviz

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So to me it still sounds like expected behavior, but if we can make our users' lives easier, then why not? :)

Maybe you could do that near and far would take negative values as well, then user could choose in which direction to extend inclusion exclusion area. The only downside to this, is that negative values would make no sense with open splines.

Or some sort of tick box 'act as closed island spline' or something like that, which is only active when using a closed spline. Sorry to be suggesting adding complexity!
Nicolas Pratt
Another Angle 3D
https://www.instagram.com/anotherangle3d/

2022-04-22, 11:50:06
Reply #28

romullus

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If you want that thsi secnario would work as open spline, then simply select one vertex in that spline and break it :]
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2022-04-22, 11:56:32
Reply #29

aaouviz

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If you want that thsi secnario would work as open spline, then simply select one vertex in that spline and break it :]

Yes, thanks. I mentioned this earlier :)
Nicolas Pratt
Another Angle 3D
https://www.instagram.com/anotherangle3d/