Prodedural Tiles questions

[Jonish]

Hello, I'm trying to recreate a wall made of marble tiles and I'm hitting a wall with procedural tiles. I'm using V-Ray 5 with GPU rendering.

1) Whenever the mortar gap is < 0,1, it tends to skip gaps and irregularly display only some gaps. Is this a known limitation? Are thin gaps a no-go for procedural tiles texture? Does this have something to do with texture resolution? Can the texture resolution be increased?

2) My Rhino mapping is set to cubic 2000x2000 mm, which is 3x2 rectangular tiles for me. Color tile = marble texture. I use UVW widget, repeat U/V set to 3x2, Randomization by Render ID, stochastic tiling, 0 tile blend. A seed, and random U/V offset and rotation. However, the texture seems to be generated only once and so the marble pattern repeats each 2000 mm, each UV tile is the same. Can this be done better way? When I tried to create a 20 000 x 20 000 mm UV tile with 30 x 20 tiles, I've run into problems with setting a thin gap, that had to be 10x thinner. See point 1.

Thanks for the help,

Jonas

[bmcveigh]

Can you send an image?

[Jonish]

Yes, here is a render, tile texture setting and its tile color texture UVW widget.

[bmcveigh]

I'll take a closer look, but in UVW placement have you tried changing the repeat U/V to 3:3 rather than 3:2? I wonder if the tile is getting stretched and therefore the mortar so it is a bit wider at the edges.
Also curious if you are rendering this with GPU or CPU. I have noticed some strange artifacts/errors when using GPU.

[bmcveigh]

In looking into this further it appears you need to up your vertical and horizontal count to get better randomness. So vertical count would be however many time fit from floor to ceiling and horizontal same or more depending on where you want the edge of the "tile" to be. Cubic mapping in Rhino would correspond to those dimensions. If that doesn't make sense I can explain another way/with images.

[Jonish]

Hi, it's GPU rendering.

Thank you, I will try to change the U/V repeat and scale up the count in both directions one more time.

Have a nice day

Jonas

[bmcveigh]

Let me know what you find out Jonas. I'm by no means an expert and still learning to make the more complex materials within VRay Rhino environment.

[Jonish]

So after some testing, my understanding is that whatever I do, the actual repeating pattern is 1 UV tile of the whole procedural Tile texture. I.e. in my case, whatever I do, the repeating tile will be 3x2 tiles, 2x2 m. If I wanted more, let's say 9x6 tiles, 6x6 m, it wouldn't work anymore because of problem with minimum "mortar gap", which is 0,1 before the gap starts disappearing unpredictably.

Not nice.

[bmcveigh]

That sounds right. You are basically repeating that custom tile pattern. I am not seeing this issue with the 0.1 gap disappearing though. I'll try and test gain today and post some images.

[Jonish]

Buuuut, whole UV tile for Tiles texture that repeats itself has its own UVW placement widget, and what I can do is to give it random UV rotation (normal and upside down). If I had 4x4 tiles and not 3x2 tiles, I could give it random rotation in 4 directions. So there is some randomization at least. : )