Vray for Maya Scatter

[thus_design]

Firstly, I would like to post in the Vray for Maya forums but I am unable to post in any of them. Any idea why? So here I am. The problem...

Am currently trying to prove Maya 23 and Vray 6.1 combo for an upcoming production. We are seeking to move on from Vray 5 primarily because of scatter (previously used Mash for this but want to move on). But we are experiencing problems.

I have surface and have scattered some trees. The trees are Vray proxies (most recent proxy type). Previewing with IPR all look good, but then all the trees suddenly lie on their side. I change a setting, any setting, and they go back upright. Unnerving. If we render to the Vray Frame Buffer the trees are always on their side, always, whether we use CPU or GPU. Rendering remotely the trees are always on their side.

For client related reasons, we work in a Z-up environment. Might this be the cause? The proxies are authored in Z-up and have no transformations. The bounding boxes are always the correct way up, but then the trees render on their side.

Can anybody help with this?. If we cannot solve this issue then I am afraid scatter will be unusable for us.

[vladimir_krastev]

Hi, thanks for posting. I will move your thread to the Maya sections and check why you can not post a thread there. Also I will try to replicate your scene. If you can send us a test scene that will speed things up a bit.

[thus_design]

I have created a new scene scattering primitive cylinders on a plane. So, as simple as possible but still in a Z-up environment. And this still has all the render problems I have been trying to solve in recent days. So it is nothing to do with proxies etc. It will occasionally render correctly but for the most part the cylinders would render flopped over on their sides.

After that I recreated the exact same scatter scene in a Y-up environment. Everything works perfectly. Time after time.

From this I take that Vray scatter does not work in a Z-up environment. That is highly frustrating because it works brilliantly for Y-up. Can this be sorted??

[vladimir_krastev]

Hi, I tested your scene and confirmed the issue. It is logged in our system under VMAYA-12405. We will notify you when the fix is ready.

[thus_design]

Thanks for the update. Always reassuring when someone else can replicate the problem showing it's not just us. I'm guessing we need to pull back from Chaos scatter for a while. Probably isn't a quick fix for you guys.

[vladimir_krastev]

There are reports about this issue trough the ticketing system from others as well. I can not make any prediction about the time this will be fixed but it has better chances for a fast completion compared to other issues.
Don't write off the Scatter just yet.

[pipe_mm]

I am using this thread to ask, if there are plans to make scatter maps visible in the viewport. Meaning to see the result of a texture used in the Density allready in the viewport.
thnx
Martin

[pipe_mm]

also I am not able to drive transformations via a map. For example to have a greyscale texture driving the rotation angle.

Attached you find an example, showing a ramp limiting the rotation of some cones - without success. perhaps someone can help me fix this.
Thnx

[vladimir_krastev]

Hi pipe_mm the issue with density maps not updating in viewport is logged in our system. We will notify you when the issue is fixed.

For the random rotation again, there is no preview in the viewport and also it does not work with IPR. These are known issues and scheduled for fixing.
In production render it works though:



You have to set the mode to "random amount"

[pipe_mm]

hello Vladimir,
thanks for your competent reply. The scatter tool is a great add on to the vray toolbox and it is good to know that those limitations will be adressed in future updates.
keep the good work up
;D

[thus_design]

I echo the above, a great add and thanks for the efforts. But desperately waiting for it work in a z up environment. Would be great, if possible, to get a heads up on when an update might occur. [but I think was have already made the decision that we need to persist with Mash or Bifrost scatter ing for upcoming production work]

[pipe_mm]

Hello
here you see the density of the scattering beeing "eaten up" by a ramp (with noise).
This seems to affect the scatter point positions.
Do you know a way to animate the density via a map without popping positions?
thnx
Martin

... please click the Nextcloud not the https in the link

[vladimir_krastev]

Hi pipe_mm thanks for the video but I do not fully understand your last post. Could you explain your test in a bit more details or a send us a scene?

[pipe_mm]

Hello Vladimir,
I would like to have a animated density map, so that the objects scattered disapear over time.
When I do so, the positions of the scatter points jump at every frame.
Here is a video of what I want to archive:

https://pipe.green-cloud.at/index.php/s/Y9HpXGW6sw4WSfB

its done in Mash

thnx

[vladimir_krastev]

This seems to affect the scatter point positions.

As far as I could tell from the video your scatter base is changing (disappearing form render)? If you change the scatter base the positions will adjust and change accordingly.



I will try to build something like the reference you've sent.