## Square Voronoi?

Started by René, July 18, 2019, 12:15:55 pm

#### René

##### July 18, 2019, 12:15:55 pm
An insightful tutorial on the Gaea facebook page. What I'm really interested in is the type of Voronoi used here, and I wonder if this would be possible in Terragen. It's in between Voronoi and square noise; ideal for making rocks.

#### WAS

##### July 18, 2019, 01:18:41 pm #1
You may be able to get something vaguely similar with voronoi displacement and strata. Hmm. Let me tinker.

#### WAS

##### July 18, 2019, 03:00:34 pm #2 Last Edit: July 18, 2019, 03:02:16 pm by WASasquatch
So I may be on to something. First of all though I noticed that if you just take a voronoi, and than a merge shader with the A input being a transform of the voronoi with a rotation in Y by 45 degrees or 90, and a scale of 2,2,2 it gives a very similar look to what you show here in displacement.

I'm currently trying to mix a X,Z square noise with a Z,Y square noise with voronoi, and than stratifying on 0 degrees and 45 degrees with variance. Rendering a test now.

#### WAS

##### July 18, 2019, 06:37:33 pm #3
I came up with this little doodle earlier. Several flavors of strata in diferent directions, and a mix between voronoi and square noise. First one is the current iteration.

#### Dune

##### July 19, 2019, 02:40:27 am #4
That's the way to go. Problem with mixing and rotating stuff like voronoi diff and smooth voronoi cell is that you easily end up with small areas that are very white/high, and that create unwanted peaks.

#### WAS

##### July 19, 2019, 03:29:36 am #5
Quote from: Dune on July 19, 2019, 02:40:27 am
That's the way to go. Problem with mixing and rotating stuff like voronoi diff and smooth voronoi cell is that you easily end up with small areas that are very white/high, and that create unwanted peaks.

Oh yes, definitely. It gets frustrating trying to colour adjust everything, than change one thing, and forget about several adjusts you have to... adjust.

#### René

##### July 19, 2019, 03:40:06 am #6
Quote from: WASasquatch on July 18, 2019, 06:37:33 pm
I came up with this little doodle earlier. Several flavors of strata in diferent directions, and a mix between voronoi and square noise. First one is the current iteration.

Those are pretty good rock textures. I myself have not been able to create something as in the Gaea example with the techniques I know, and believe me, I tried. Maybe it is possible with a good knowledge of blue nodes. However, the type of voronoi in Gaea seems to come straight out of the box.
A quick google and all kinds of voronoi appear, so it seems that this particular kind of voronoi must be built into the software. If that's true, I have to resign myself to the fact that it's out of my reach.

http://www.neilblevins.com/cg_education/procedural_noise/procedural_noise.html

https://en.wikipedia.org/wiki/Voronoi_diagram

#### WAS

##### July 19, 2019, 03:53:45 am #7 Last Edit: July 19, 2019, 03:56:40 am by WASasquatch
Quote from: René on July 19, 2019, 03:40:06 am
Quote from: WASasquatch on July 18, 2019, 06:37:33 pm
I came up with this little doodle earlier. Several flavors of strata in diferent directions, and a mix between voronoi and square noise. First one is the current iteration.

Those are pretty good rock textures. I myself have not been able to create something as in the Gaea example with the techniques I know, and believe me, I tried. Maybe it is possible with a good knowledge of blue nodes. However, the type of voronoi in Gaea seems to come straight out of the box.
A quick google and all kinds of voronoi appear, so it seems that this particular kind of voronoi must be built into the software. If that's true, I have to resign myself to the fact that it's out of my reach.

http://www.neilblevins.com/cg_education/procedural_noise/procedural_noise.html

https://en.wikipedia.org/wiki/Voronoi_diagram

I've mentioned some.other flavor noises based on perlin and voronoi and even others not implementee at all but Matt mentioned he had no plans to add any more noises and that with the SDK it was easy enough to add them. Still don't know much about the SDK. If I knew more I may be able to do something based on open source noises, if not have a more professional coding buddy help.

It really seems like a needed featture, more noises. All these programs like Gaea and substance designer have out of the box is tons of noise flavors for interesting mixes without algebra and trigonometry.

There seems to be a heavy wave going about on highly realistic procedurally generated PBR rocks to export and make seemless. Probably cause they look photorealistic without the 3D scanned model price tag.

#### René

##### July 19, 2019, 08:06:39 am #8
Additional types of noise via the SDK would not benefit me because I work on an iMac; as far as I know there is no SDK for os x yet.
I learned by now that the type of voronoi I mean is called Manhattan. It seems to me to be indispensable for the creation of credible rocks.
Looking at all the hyper realistic textures of Quixel and Substance makes my mouth water, and they have raised the bar for texture creation.

#### Dune

##### July 19, 2019, 08:27:32 am #9
Well, maybe Matt cóuld add the Manhattan voronoi if it's free and not too complicated. I don't anything about such things. Only that a lot of work is based on rocks, and it would be a very welcome feature. I've been trying this stuff for years too, but it's terribly difficult to get the holy grail.

#### René

##### July 19, 2019, 10:15:33 am #10
I realise it could be a cost-benefit issue, but it would make a huge difference to have this kind of noise in Terragen. Moreover, fake stones and the Alpine fractal are also based on voronoi, so there would be interesting possibilities in that area as well.

#### mhaze

##### July 19, 2019, 10:50:06 am #11
I agree with every thing said here, it's a desperately needed tool.

#### WAS

##### July 19, 2019, 01:43:39 pm #12
I'm going to leave this right here: https://rosettacode.org/wiki/Voronoi_diagram

Matt could make this happen. I see a lot of voronoi diagrams and functions out there. Though I do notice most are just basic grids like vector voronoi we have now, which we can warp... Though not well. It would be nice to have a function that works for stone out the box driven by seed and scale.

Our issues stems from our math abilities to mix these diagrams into something usable for stone.

#### WAS

##### July 19, 2019, 02:54:11 pm #13 Last Edit: July 19, 2019, 08:28:43 pm by WASasquatch
Mixing stepped voronoi, with scaled rotated voronoi, than stratified at 45 degrees on 90 direction and 45 degrees on 0 direction. Than we mix by highest.

The issue here is the strata isn't lateral, so this effect is lost with actual use in most situations we want it for.

Edit: here is some raw math notes on the l1 norm diagram: https://xlinux.nist.gov/dads/HTML/manhattanDistance.html

#### Dune

##### July 20, 2019, 02:18:01 am #14
And strata is hard edged, and we actually need something like the smooth voronoi.