Planet Pig

Started by efflux, October 30, 2007, 03:44:34 AM

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efflux


dhavalmistry

"His blood-terragen level is 99.99%...he is definitely drunk on Terragen!"

efflux

Here's a first semi realistic environment where I tested this perlin strata thing:


rcallicotte

#33
Efflux - I've just tried your setup from above without any results.  I followed everything you said to a T by going by your graph and instruction.  No reaction from the surface whatsover.


[EDIT] - NEVER mind.  I wasn't in the right area of the planet and / or I didn't have the settings balanced correctly.  While I have work to do this is what I have been able to do so far - [/EDIT]
So this is Disney World.  Can we live here?

old_blaggard

That looks pretty darn cool, Calico.
http://www.terragen.org - A great Terragen resource with models, contests, galleries, and forums.

efflux

#35
That look good Calico.

I'm trying to ease you into understanding this. First you want to get those perfectly lateral strata like around those bluish towers I did. If I supply a tgc then it's not so good in my opinion and this technique is dead simple anyway. Once you know how to set it up then you have huge power to use it whoever you like. The real diificulty is actually simply in getting the right scales for the perlin and the displacement so it's the size you want to see in your scene.

The distortion is another matter but something that needs worked on and explained a bit better because for strata we definitely want that distortion. This is the real power behind this idea. It wasn't explained on the voronoi thread but it was in a WIP phase and still is. I'm still trying to work though it myself though. It's tricky due to TG2's separate use of colour, scalar and vector. However this does give TG2 flexibility.

My opinion is that this perlin strata is a major technique allowing for amazing forms that are very useful for natural effects. Bring in colour and it starts to get very interesting.

I had intended to stop with TG2 for a while but I will have to work through this idea a bit now. It's like the last frontier big frontier.

This should be a new thread really but never mind. These discussions are a bit messy anyway. Maybe in the future it can all be sorted out into better to understand tutorials but believe me, get into this and at least try to get some of it understood because the TG 0.9 users who aren't exploring these things are going to be left way way behind.

efflux

#36
I think the displacements disappear when you go beneath an altitude of zero but that's a side issue. We'll get all this sorted.

efflux

You can of course get similar effects without using blue function nodes and using other shader setups but you don't get the same flexibility. I think that has been demonstrated on the voronoi thread. Can you do that stuff with fake stones (which are voronoi)?

efflux

#38
This is how to set up the distortion fractal plugged into the perlin. The scale settings page effects the amount of distortion. So if you want not much strata distortion then make the scales very large and also here it's best to have smallest scale scale fairly large. The colour settings effect the size of the strata. You want these setting to reflect the amount of detail you want in the strata. Colour is irrelevant (at this stage). Ignore the 0-1 colour numbers. Switch off the clamping and adjust high and low colour according to the scales you want. You don't want lots of detail with this so make both high and low fairly large or the size of the strata, not 0-1 or higher than 0 for low - it all depends on your scales in the planet, you'll find the right settings (there are lots of ways but this is how to start simple - just adjust colour). Later displacements and detail in your terrain will add finer detail but there are no hard rules here except you don't want a displacement mess. The colour roughness will also straighten out the strata. Play with this stuff and you'll see.

A lot of these settings all interact with each other but you'll learn that. Some of the different settings will get you the same visual result so not so easy to explain it all. By experimenting you'll see.

Kevin F

Here's my first attempt at the "piggy technique". As you say Efflux the scale settings are crucial. But once you get it right it's very easy to manipulate. Lots of fun to be had here!
I've got a couple of others rendering at the moment and will post later.
Thanks for this Efflux - we'd be lost without you. Although I'm partly lost because of you! ;D
Regards
Kevin

efflux

Here's another variation. In this graph I retained the clamped 0-1 colour values but multiplied the fractal's output before going to the perlin. By retaining the 0-1 colour value it can be useful for other purposes. In this case I drove the blending shader on a power fractal which is supplying colour to the surface layer. You could also get outputs from after the perlin. There are numerous ways to drive the colours. In fact this is probably even more useful than using it for displacements.

The problem is to do with TG2's shadows. You'll find they screw up with displacements like these as they do with all distorted displacements. A serious problem but maybe it will be improved.




rcallicotte

Efflux, I just woke up to your explanations.  Thanks.  I'll have some time today to play with this and maybe mix it up a bit with voronoi discoveries I've made.  I'll post what I find here and try to keep relevant.   :D
So this is Disney World.  Can we live here?

efflux

Yes, the important thing is simply getting the scales of everything just right or things look rough and broken. Your image is cool and this is really easy so anybody can use it but try adding the distortion fractal if you can work out what I've said about how to do it. Then you get into even more scaling issues. the only way is to experiment.

Also, it might be a good idea to not go too crazy with the displacement multiplier value especially since we might run into shadow problems. My examples for everything are really extreme but I do that to really show what is happening.

There will be other issues and loads of tangents coming off this idea but I'll not go much further with it. The basics are laid out now. The distortion thing is very cool because that can be used for other techniques not just this strata thing.

efflux

#43
Just to back up what I've said. Don't go to crazy with these things and try to make settings so that you don't get a lot of small rough details all over the place otherwise it won't look smooth and realistic. The terrain provides detail and further overlying displacements can provide detail. Some displacements can have low detail and be very smooth, just providing a general shape, otherwise you'll get clashes of displacement detail everywhere.

For example in the tests you guy's have posted, the terrain is already rough. Make the displacements have low detail. High smallest scale, low colour roughness etc. You'll find all this out by tweaking. My original examples are smooth but your terrains will provide roughness. It goes further though because really what you want is various layers of subtle things going on. A reasonably detailed terrain, other displacements to provide shape and then more surfaces over the top to provide the real detail. At least that's the way I work. It's not the way everyone does things but it's what TG2 can provide over TG 0.9.

efflux

Your pictures demonstrate the shadows problem by the way. This is one reason to not take this too far and have lots of huge rough displacements. Matt may improve that. I don't know.