Advanced Coloring Techniques?

Started by blattacker, June 20, 2019, 04:17:29 AM

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blattacker

Hey there! So I've been working in Terragen on and off for around 6 or 7 years, I think, but I want to start taking it a bit more seriously. To that end, I was wondering if anyone had any pointers, or links to references/tutorials on more advanced/realistic shader techniques? I've included my latest project as kind of a reference of where I'm at now (there's clouds in the final project, but they were left out on this render for faster times, I'm working with a computer that was built in 2009). Most of my current technique is just several surface layers of a base color, then child layers for each individual component with variations on the color. I'm starting to work a bit more with different masks, but it's not immediately clear how to get the result I want.

I build my heightmaps in World Machine, export (in this case at 16k) to a .ter file, then bring it in to Terragen.

blattacker

A quick search has taught me about the use of the Color Function input on nodes, which has been very helpful, and probably a bit obvious. Are there any other functions that may be obvious to people who know what they're looking for, but maybe a bit less obvious to those who've only casually played around with the program?

WAS

You pretty much got it all. You can also create "difference" colours with a merge shader, which can give you different levels of complementary colours to your mix.

Here I've attached a basic example of some complex colour shading in Terragen.

Additionally take a look through my Stratified Rock Colours TGC.

Oshyan

Take a look at the Resources page on our website as well as the Free Downloads for examples to look at, take apart, and understand. Also the GeekAtPlay tutorials (on the Resources page as well).
https://planetside.co.uk/terragen-resources/
https://planetside.co.uk/free-downloads/

- Oshyan

blattacker

Oshyan: The resources page I'd seen, though I haven't quite finished going through them. I can't believe I didn't know about the free downloads page though, I'll have a ton of fun picking apart some of those files!

WASasquatch: I'll have to check those out, definitely! The merge shader is a new one for me, so I'm excited to see how that one works!

I'm not gonna lie, when I first started doing 3D in general, even before Terragen, I hated node-based systems, but the more I use Terragen, the more I wish everything was node-based!

René

The easiest way for me is to create patches for each texture group which is easy to visualize via the test color in the surface shader. You can divide these patches into subpatches if necessary. A masked color adjust shader at the end of the shader tree can provide even more variation. Distort by normal in the power fractal shader makes the textures even more complex but this requires some experimentation to get a feel for it.
The attached example is over the top but shows what is possible in this way.


WAS

Thanks for sharing some wisdom Rene. Nice surfaces distribution.

René

I forgot to mention that distort by normal can really work wonders if you use it wisely. Set color roughness low to 1 or 0 and the power fractal conforms to the previous displacements.

WAS

That's how you are doing the colour working with lateral displacement! Great share thanks!

René

Usually I feed the power fractal through a tranform shader, 'use world space' enabled.

bobbystahr

Brilliant solve there René...noted....
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

WAS

#11
Been playing around with the technique a bit, and it is a bit of a trial and error getting scale of normal right without things looking too broken up, but can make for really interesting shading.

René

You're on the right track, by the looks of it.  High values of roughness and distord by normal only result in shapeless noise; it depends on the size of the power fractal and the underlying structures. It is indeed trial and error. The only downside is that it sometimes gives the appearance of glossiness in places where you wouldn't expect that.

WAS

#13
Quote from: René on June 26, 2019, 09:02:51 AM
You're on the right track, by the looks of it.  High values of roughness and distord by normal only result in shapeless noise; it depends on the size of the power fractal and the underlying structures. It is indeed trial and error. The only downside is that it sometimes gives the appearance of glossiness in places where you wouldn't expect that.

Yeah, sun angle kinda influences the effect a bit too. At the wrong angle (like in my scene) the sun is facing the plaster-like brown roughness, which like you said, almost looks like highlights rather than texturing. Looks good in shadow though--

Additional advise, you can also "target" influence your PFs by feeding their main input different aspects of your terrain geometry down the chain. For example, if your final lateral displacement have too much detail, you can use underlying shape geometry before detailing.

If you use colour shading like I do with functions, you won't have to worry about displacement feeding through your colour chain into the child node, or you can just feed into the Surface Layer colour tab. The distort by normal will now follow the displacement you fed it in all your PFs. This can also be used for masks. When using as a mask, it seemns to effect the noise with lots of half tones, black, and some white, giving you a great mixing mask where half-tones will be semi-transparent allowing extra detail from down the line to show through and not be completely masked.

René

And it's also a great way to distribute vegetation – real or fake – in interesting ways.