Issues with UVWRandomiser and Real World Map Size

[RecentSpacesSam]

We recently discovered that when you use a UVWRandomiser in conjunction with real-world map sizes it produces some strange looking results.

In the attached image both squares have a similar material applied. The one on the left is using a UVW modifier set to 130cm box and the bitmaps are set to 1:1 tiling.

The one on the right is using a UVW modifier set to "real world map size" and box, the maps are then set to real world size 130cm (or tiling of 0.008)

Both sets of maps are being run through CoronaUVWRandomiser maps with the following values:
U Offset - from -1.0, to 1.0 step 0.0
V Offset - from -1.0, to 1.0 step 0.0
W Rotation Offset - from 0.0, to 360.0 step 180.0

Randomise each tile: Y

Everything else is default.

What I believe is happening is that the UVWRandomiser is randomising at the boundary of each UVW mapping tile (1cm in the realworld UVW case) rather than the boundary of each texture. Whilst the functionality is "corrrect" the ideal scenario for realworld map sizes is that the offsetting is done at the texture boundary - at least where rotation is concerned.

When offsetting is zeroed out and only rotation is used the issue is less noticeable but still present.

The issue is not present when using triplanar, although I noticed the blend line seems more hazy/lacking in contrast.

max 2022.3.10
Corona 9.1

[Aram Avetisyan]

Hi Sam,

I am not quite sure what is the exact issue in your case, or maybe the screenshot conveys little information. To me it looks like a scaling issue for the plane on the right.

Here are the test I have done.
Everything was working as expected for me, no texture blurriness or issue of any kind.

I have set up the randomizer with the settings you specified, sampled the texture from the screenshot, added a red border so the randomization is clear.

The left plane is 50x50xcm, uses tiling, with a UVWMap completely covering it, 50x50cm.
The right plane is 50x50cm, uses real-world scale, with UVWMap with real-world scale, texture is 50x50.

The change is in the tiling of the image (1 to 5) and the texture size for right plane (50cm to 10cm)

Everything else is the same with the setting you specified.

On thing I noticed: if you change the UVWMap to 5 times smaller (instead of changing the texture tiling from 1 to 5) and/or moving the UVWMap gizmo for real-world scale texture from center to any corner, the results may vary, it seems that the texture is somewhat double-tiled and then randomized. I don't know if this relates to your case and if it can bring any improvement.

[romullus]

On thing I noticed: if you change the UVWMap to 5 times smaller (instead of changing the texture tiling from 1 to 5) and/or moving the UVWMap gizmo for real-world scale texture from center to any corner, the results may vary, it seems that the texture is somewhat double-tiled and then randomized. I don't know if this relates to your case and if it can bring any improvement.

Not quite sure, but this could be related to this bug: https://forum.corona-renderer.com/index.php?topic=39294.0

[Aram Avetisyan]

On thing I noticed: if you change the UVWMap to 5 times smaller (instead of changing the texture tiling from 1 to 5) and/or moving the UVWMap gizmo for real-world scale texture from center to any corner, the results may vary, it seems that the texture is somewhat double-tiled and then randomized. I don't know if this relates to your case and if it can bring any improvement.

Not quite sure, but this could be related to this bug: https://forum.corona-renderer.com/index.php?topic=39294.0

I think it was this, yes.

[Aram Avetisyan]

On thing I noticed: if you change the UVWMap to 5 times smaller (instead of changing the texture tiling from 1 to 5) and/or moving the UVWMap gizmo for real-world scale texture from center to any corner, the results may vary, it seems that the texture is somewhat double-tiled and then randomized. I don't know if this relates to your case and if it can bring any improvement.

Not quite sure, but this could be related to this bug: https://forum.corona-renderer.com/index.php?topic=39294.0

So for this (Double/Mirror tiling when using Randomizer at the center of UVWMap): the reason behind is the "Number of Tiles" parameter apparently. It seems that if the number is higher than 1.0 (even 1.01), there is no such issue. Both for RWS and Tiled modes.
This is reported now (duplicating in the original thread as well).

(Internal ID=1184325933)