Latest update reverts ZIndex property of Decals/textures, causing Z-Fighting

[DataBrain (Amber)]

Reproduction Steps
I just barely adapted the new ZIndex property of decals in my game for the face editor, only to find that this property has been reverted. Now I’m getting terrible Z-Fighting.

Reproduction steps: Place two decals on the same surface , with a different ZIndex. They will Z-fight instead of overlaying in the correct order.

EDIT: This only happens in my own place; thanks to the staff for reaching out to me privately to get this issue fixed.

Expected Behavior
Decals should layer correctly

Actual Behavior
Decals will now z-fight, with one layer appearing over the other inconsistently.

Workaround
No.

Issue Area: Engine
Issue Type: Display
Impact: Very High
Frequency: Constantly
Date First Experienced: 2021-07-21 16:07:00 (-06:00)
Date Last Experienced: 2021-07-21 16:07:00 (-06:00)

[tnavarts]

Could you share a model to repro with? I tried a couple trivial test cases and it worked fine with those.

[DataBrain (Amber)]

I sent you a DM. I don’t want to share this publicly right now though.

Edit: It looks like this only happens if the decals are wrapped over a MeshPart.

[tnavarts]

What version / platform are you on? (full version number including the patch number since there was a patch release very recently)

I tried the repro and it worked for me.

[DataBrain (Amber)]

Windows 10

Edit: I sent you a full place file; I guess this bug isn’t as consistent as I thought it was.

[hyperhumanist]

This should be fixed now. @DataBrain , can you please check if it works for you and let me know? Thanks!

[DataBrain (Amber)]

Seems to be fixed on my phone. Thanks for investigating this issue, even if it only happened on certain games like my own!

[DataBrain (Amber)]

Looks like I’m getting a different issue now, possibly related to Z-ordering/sort stability?

Whenever lighting is in shadow, my characters’ eyes are now turning black on occasion, depending on what orientation they are facing.

This ONLY happens on future lighting though, so ShadowMap/lower graphics qualities don’t get this bug.

Like the bug in the OP, it scales up with the number of players together/the number of semitransparent parts or decals over transparent parts around.

https://i.imgur.com/qSNETlL.mp4

Unfortunately I can’t create a repro without sharing things I don’t want to be public yet.

[TEARAPARTJAMES (FROGMIRE)]

@DataBrain

Whenever lighting is in shadow, my characters’ eyes are now turning black on occasion, depending on what orientation they are facing.

I am also having this little issue occur in my game. I found out what was causing it. It is due to Forcefield material parts. Here is a repro. decal issue thing.rbxl (25.5 KB)

For anyone who wants a temporary fix, just make all forcefield parts into a different material.

[vrtblox]

hello, may i ask what is the issue in the file attached? would you mind DMing me and share more info? thank you!

[Sir_Highness]

I think I’m getting this recently(couple days) even with simple transparent parts. I made thin lines like parking lines on pavement, if you lower the viewing angle the line turns black. The lines are at .4 transparency to show the texture underneath. If they don’t fix this i’ll have to make them opaque I guess.

pictures of the issue:

The light and dark lines flicker seemingly with angle of view, but sometimes just flicker anyway. ??

That is a white part stripe with .4 transparency.

[vrtblox]

would you mind sharing repro place? thank you

[Sir_Highness]

Sure give me a bit, gotta make a baseplate with a part on it…

[vrtblox]

alrighty, sounds great, thank you!

[Sir_Highness]

Well, you’ve stumped me! I can’t get a baseplate to do the problem. Trying to figure out what is different about my places that have this problem.

Getting something together for ya, hopefully, I think I’ve found a clue, its something to do with a FORCEFIELD being present in the game. (I think)

[Sir_Highness]

Got it, stand near the white part, rotate the screen and watch it change colors:

transparency test

If I delete the forcefield part, it does not behave this way. It also seems to have something to do with a skybox and specular lighting set to 0 makes it way more apparent also. I’ll allow copying in case you want to edit it.

[vrtblox]

thank you! i’ll take a look what’s going on

[vrtblox]

the issue has been identified, we’re working on a fix and release it asap. thank you!

[Sir_Highness]

The transparency problem is fixed for me now. My test place doesn’t change colors now when you add/remove a forcefield.