Joshua Tree National Park first WIP

[Chinaski]

Forgot to say one thing : There is not a good and a bad way to do that. The two method are very good. With Martin's technic you work on an axis (and repeat & deform), with mine you work on cells (and deform with vector). The first one give you a regular aspect, the second one a cheesy aspect. Maybe you could try to mix them together...

NB: About the cell method you can read this thread. Efflux explanations are, I think, the best way to understand it.

[zaxxon]

Thank you for your generous work and great shared examples. All the trig talk with blue nodes is a bit heavy, but these types of shared files really help the process of understanding TG's more 'esoteric' abilities. Again, thanks!

[TheBadger]

Good to see you around and posting Chinaski! Nice files as always, thanks from me too

[gregtee]

I agree.   I'm really glad that this thread has developed into something that anyone can take something from and not just about my images.  I can't wait to get home tonight and plug these in. 

Thanks again for the help!

-greg

[TheBadger]

These are the best kinds of threads from a learning perspective. When people start sharing everything they know on a single subject, man, you can learn a ton fast! Your image and project creates the common denominator. OF course, now we are all going to want to see what you do, greg! 

[gregtee]

Ha.... no pressure...   

It's a good thing I have an understanding wife.

[gregtee]

Hi Chinaski,

So I managed to plug in your 3rd version into my script and overall it's working, but I can't figure out how to get the sand to not crawl up the side of the rocks in places.  You can see on the foreground parts here that there's sand on places that I don't want it, mostly over on the lower right side of frame.  I really only want it on flatter areas.  It shouldn't be on vertical parts around the base of the rocks themselves. 

Is there a way to control this?  I tried using a surface layer and the slope controls but it's just not working. 

For the most part the sand is looking great, I just am going crazy trying to control how it rides up the sides of the rocks where it shouldn't.

-greg

[Chinaski]

Yep, that's not the result we expected.

Can I please see your file (not sure I can do something, or even open it in TG2, but...)?

[gregtee]

I'll send it to you. 

Thanks for helping me out.

-greg

[gregtee]

Ok, since you're in 2.5 I've stripped this down to the minimum of nodes to (hopefully) avoid possible version issues using mostly what you've already posted but switching out some of my displacements for yours.  It still illustrates the same problem even if it's not the exact same file I rendered in my last post so if you can get it working here I should be able to get it working on my end. 

Thanks again for taking a look.

-greg

[TheBadger]

Hi greg,

I just am going crazy trying to control how it rides up the sides of the rocks where it shouldn't.

So this was one of the original problems right? And its because you can only limit by hight and slope one time, which effects everything?

Oshyan and ulco told me how to deal with that, but I don't remember what they said. I tried to paraphrase earlier. Basically I think you need to have more then one layer of the sand limited by area, so that you can use more than one distribution shader, so that you can have different levels of control for altitude over your not flat terrain.

Is that right Greg, and guys? If not, the issue I described is still a problem for me at least.

[gregtee]

I think I pretty well understand the concept behind Chinaski's approach.  He's using two planets (or planes in his posted case) to generate his displacements and then combining them.  The problem I'm having is the "sand planet" has sand on areas that I don't want it and it's seeping through to the main terrain planet, manifesting itself in ways I don't want. 

I have managed to control the slope of the sand on the sand planet so it really only shows up where I want it but the problem is that it leaves behind areas of black that carry on through to the main rock planet.  I tried making a mask layer from this slope controlled sand planet and merging the two together but again, it created black holes in the main render. 

I know this can be done, he's already got it working on his file he posted but for some reason when I swap out my displacements for his part of the terrain parts of mine break. 

[Chinaski]

Hmmm guys, we are in trouble!



I'll try to figure out, but it will be hard (working sort of blind here).

About the second plane (or planete or whatever object) trick... If I have two planes I don't need to merge my textures. It's just a little solution to a specific problem with the merge shader. I don't even know if this problem still exist on TG3.

On TG2, WHEN (and only when) I have artefacts with the merge shader, I thinking like this: sand = water, problem solved! So I make a "lake" of sand, and it's solve my problem. It's not elegant, it's a cheat, but it work (typical example: sand dune on bottom of a martian crater).

Now, if you want to distribute some sand in your scene, TheBadger is right, you need a distribution shader (or a surface shader) to place it in the scene.

[gregtee]

I gotta say this setup you made Chinaski for the dunes is very cool.  It reminds me a lot of these old fractal patterns I used to mess with way back in the mid nineties during my early Lightwave days hanging out with a guy named Steve Worley.  He used to come over to my house when he was in town and show me all his new fractal based plugins for Lightwave and the patterns they made look exactly the same as what you have here.  It's like a lightbulb just went went off in my head and I now realize what this things do. 

I think I'm getting a grip on it now.

Thanks again!

-greg

[Kadri]

Greg you mean the famous " http://www.worley.com/ " ?