UVW randomization issue

[romullus]

I tried to setup atlas texture randomization in decals, but i found that UVW randomizer gives unexpected results if decal mode is used in conjunction with mesh element mode. The setup works with either of those modes alone.

Select any UVW randomizer map in the attached scene and turn on/off mesh element mode. Watch how result is breaking when both decal and mesh element modes are on. Don't mind the missing bolts - that is by design.

P.S. i'm not sure, but i think i did similar setup in the past and there were no issues with it, so it could be that the bug is pretty recent.

[Kris H]

I tried to setup atlas texture randomization in decals, but i found that UVW randomizer gives unexpected results if decal mode is used in conjunction with mesh element mode. The setup works with either of those modes alone.

Select any UVW randomizer map in the attached scene and turn on/off mesh element mode. Watch how result is breaking when both decal and mesh element modes are on. Don't mind the missing bolts - that is by design.

P.S. i'm not sure, but i think i did similar setup in the past and there were no issues with it, so it could be that the bug is pretty recent.

Hi Romullus,

I downloaded your scene and for some reason it renders differently than I can see on your pictures, and ticking/unticking the Mesh Element option doesn't do any difference. We tried ticking/unticking all the Randomize by options in CoronaEvwRandomizer, reloading the input picture, but we can't get same result like yours, even in earlier daily builds.
If the issue still persists could you please try and send us the scene again? Also, in which version of 3ds Max is this reproducible?

Thank you in advance,
Kris

[romullus]

Hi Kris,

Hmm, that's strange, it looks like randomization doesn't work at all on your side. I will double check my scene sometime later - maybe i sent you the wrong one.

edit: i'm using 3ds Max 2023.2.2

[Frood]

Hi romullus,

U and V offsets in UVW randomizer have to be set to 0.2 in your attached scene (they are at 1.0), then disable Instance and activate Mesh Element -> displacement gone. Presumably because displacement points to an empty map area / randomizing wrongly. I guess it is this (long known) issue:

https://forum.corona-renderer.com/index.php?topic=36586.msg198696#msg198696


Good Luck

[romullus]

My mistake, initially i had tiling set in UVW randomizer, then later i moved it to bitmap and probably i forgot to save the file to its latest state. Anyway, i fixed the scene and now it should render properly, i.e. the issue should be present like in the screens.

I guess it is this (long known) issue:

https://forum.corona-renderer.com/index.php?topic=36586.msg198696#msg198696


Good Luck

Ah, i wasn't aware about randomization issues in mesh mode. It looks that in my case it's not only displacement channel that is randomized wrong though.

[maru]

Duplicate of https://forum.corona-renderer.com/index.php?topic=25627.0

[rowmanns]

Fixed in v11.

https://forum.corona-renderer.com/index.php?topic=40442.0

Rowan