Flickering impostors in Unity 2018.3 HDRP

[BroPoly]

Hello everyone,
Our studio recently moved from a well known engine to another : Unity.
This decision is motivated by Unity's potential in performance saving and HD render pipeline development.

In our game, the camera displays a large scene with thousands of trees at the time ; we then decided to use an impostoring system and amplify's announcement made its effect on us.

After a few days trying different possibilities, i'd like to share my feeling about this and hopely get feedback from you guys on the issues i experienced.

First, A.Impostors is indeed really intuitive to use ; one click bake is reel. It has a few parameters to play with, but in the end you'll always get your impostors easily ; which is great.

Now let's get into the weird stuff. For our test we planned to use 5 tree species; create impostors from highpoly models and then duplicate them in our scene with different rotation and scale values to fake variations.
We figured out that a same impostor, duplicated with different scales still conserves same parameters for both of them; resulting in weird atifacts, especialy when the camera is moving.
I suppose duplicating them doesnt create shader instancies, which gives an answer.
From this point we decided not to use different scale for same species and the first issue was resolved.

And here happened the second issue.
From a certain camera angle, our impostors are flickering (see GIF).
https://gfycat.com/ForsakenEarnestAllensbigearedbat
I tryed disabling Post process/volume profile, tested the channels one by one, changed the lighting ... nothing changes.
Do you have any idea on whats happening ?

[Amplify_Borba]

Hello, thank you for getting in touch and for your support!

It's very hard to tell by just the gif itself, we've come across a similar behavior in another project that had a moving light source, which is still being investigated by the developer.

Which Unity, HD RP and AI versions are you currently using?
Are you using standard shaders or custom ones in your objects?

Can you replicate the issue in a new project and send us a simple sample for us to debug on our end using the same data as you? Feel free to send it through [email protected] with the link to this post and we'll look into it as soon as possible.

[BroPoly]

Unity 2018.3.7f1
HDRP/Core 4.10
AI 0.9.4

I created a simple project in which i replicated the issue, will send it to the link in a minute.

Thank you for the support !

[Amplify_Borba]

Thank you for the additional details!

We've found the issue to be related to instancing and will be fixing it for the next Amplify Impostors build, which should hopefully be released soon.

[EDIT] And since the issue was due to improper instancing having different scales like you first tried should be working correctly as long as the scale is uniform in all axis.

[BroPoly]

Alright, i'll keep an eye on this next build then !
One more question, if i may (a little off-topic).
Do you plan to make A-Impostors compatible with Unity 2019x in a short future ?

[Amplify_Borba]

You may access the latest build through our website in case you haven't already, all feedback is welcome!

We're planning to officially support Unity 2019 as it comes out of Beta stage, it's unlikely that we can offer support for any of our assets before that stage due to our limited resources.