Smooth Terrain decoration visually glitches when loading in

Bug Reports Engine Bugs
#1

Issue:
When in studio and in a live game, roaming the map quickly and teleporting causes grass decoration to visually stretch and load incorrectly. This causes a momentary visual glitch until the game is able to load in the grass fully (after a few ms)

PC Info: Windows 11 22H2
Date First Experienced: 7/6/2023
Date Last Experienced: 7/18/2023

Replication Steps:

  1. add terrain
  2. enable decoration
  3. quickly move across the map in studio with lots of terrain (using scroll wheel)
  4. grass appears stretched vertically, and visually flashes sometimes.

Repro File: (taken from my current game, and removed all non smooth terrain parts)
TerrainRepro.rbxl (644.1 KB)

attached is a video of the issue. Disabling decoration solved this issue.

10 Likes
Grass Terrain Streaming In Artifacts
#2

any update on this? It is still occuring :confused:

Zooming in and panning the camera also causes a momentary visual glitch in the terrain.

I believe I have enrolled in the new shorelines, but I also disabled beta for that afterwards and it was still occurring.

#3

@hyperhumanist hi I noticed you are on the terrain team, any way this could get looked into soon? Thanks!

1 Like
#4

Additionally, when trying to paint, grow, or smooth terrain, the terrain flickers and gives me an epilepsy.

3 Likes
#5

After further investigation, using the built-in developer freecam (shift + P), this seems to be the only time when it visually glitches anytime I slightly update the camera position, fov, or rotation.

2 Likes
#6

@Focia19 hi sorry for the bother. Its been about 2 weeks since this has been created, any way this could be pushed along? :slight_smile:

#7

A ticket was filed for this issue and was assigned to the right team of engineers!

I will give them a heads-up!

3 Likes
#8

Hi Dan!

We are not able to reproduce it locally. Can you describe super exactly how you get this to start happening? Are you in play mode (local or regular) are you only using fly cam? I cannot reproduce it on any of my systems. Is it still happening for you?

Also. We will be (very likely) flipping flag with fix for grass flickering which is very likely related. In the morning PST. I wonder if that will help. I’ll let you know once the flag is flipped. It will definitely be fixing the “epilepsy” issue

1 Like
#9

Flag with fix was flipped. Please let me know if it fixed your issue. @DanBuildsTrains

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#10

Hi, thank you for looking into this.

For me it still is broken after restarting studio.

It happens both in-game and in-studio.

In-game occurs when:

  • teleporting to another end of the map (loading in terrain)
  • using the developer free cam (shift + p) and zooming, or updating the camera in any way causes the grass to flicker

In studio occurs when:

  • moving across the map quickly with scroll wheel (causes the grass to stretch and float for a moment)
  • teleporting to another end of the map in play test mode (loading in terrain)

I am trying to figure out how to replicate this issue, I am unsure what is actually the cause and cannot replicate it myself on an empty baseplate. It seems to only occur in this specific world, even when publishing to a new place. I am wondering if it has to do with the part count? But it doesn’t make sense because I made a minimum repro with all the parts/effects removed and JUST terrain and it still does this (see attached place in OP)

Here is a link to our place that is experiencing this issue.

1 Like
#11

Here is a video of the free cam issue taken just now:

1 Like
#12

Thanks for the reply. I’ve tried these steps and cannot repro locally. I also tried your repro file. Are you sure that you have FFlagTerrainFixGrassFlickering set to true on your machine?

anyway if you would be so kind: can you try to create a file (that does not contain any of your IP of course) that has the camera set at position that repros and maybe create a part to which I should fly towards quickly with camera that constantly causes this issue. Or anything you can do to make it more specific.

I would greatly appreciate it. Thanks!

#13

Hi, how can I check if FFlagTerrainFixGrassFlickering is set to true or not?

#14

I’m having the same issue as well

1 Like
#15

Oooops I guess you cannot. I’ve forgot that fflag watcher is an internal roblox studio feature sorry! :slight_smile:

Anyway does the issue happen only in the free camera mode? Can you please answer these questions? I guess there are 3 issues right? One is stretched out grass and second is grass flickering while editing and third is grass flickering in free cam?

  1. stretch out grass happens no matter which mode are you in right? Did it really just start happening to you around July 19th? Is this correct?
    2 ) grass flickering while editing is fixed now right?
    3 ) grass flickering in free camera mode is still happening but is only isolated to the free camera? Is that correct?

Thanks!

#16

Hi,

Yes there are 3 separate issues here, but I am not sure if any of them are related to the same issue.

  1. Yes the grass stretches while terrain loads in, this is either from zooming across the map too quickly in studio (or a live player client), or teleporting to an unstreamed section of the map before it fully loads in.

  2. This issue is confirmed to be fixed as seen in the video below:

  3. Yes, using free camera only causes the grass to disappear completely, and only sometimes reload in thinned sections or fully decorated terrain. Please note that this is only happening on the built-in roblox developer free cam (shift + P). Custom free-cam plugins work just fine and as intended.

Built-in roblox dev free cam (shift + P) causing issues:

Intended behavior with custom free cam:

I would also like to point out I am still using the old terrain editor, not the new one in beta.

1 Like
#17

All of the issues were identified and fixed locally. Fixes will be coming out in next releases.

Thank you very much for your help!

2 Likes
#18

Excellent! Thank you so much for the help and assistance. I hope my report wasnt too confusing.

#19

No we very much appreciate your report. What was confusing that there were more underlying issue at the same time

1 Like
#20

Is there any way you could explain what the problem was? Im curious to see if it aligns with my theory, and to maybe learn something new about how terrain works :slight_smile: