Joshua Tree National Park first WIP

[gregtee]

Speaking of that operation, I haven't had much success using that operator yet.  Are there any good examples on the forum of its use? 

[archonforest]

This image is getting really cool. The color, shadow, lights are awesome!
Cant wait to see the end product

[Dune]

It's quite simple; it tilts the X or Z displacements (or y if needed) by a factor, with the base height as pivot point. So if at 100m high, set at 100m high, or it will tilt from 100m below, moving the whole terrain sideways.

[gregtee]

I'm taking a huge step back on this until I can figure out how to do this correctly.  No color corrections this time.  The issue is that I can't for the life of me figure out how to get the sand ripples to lay over the rocks without also adding their displacements to them.  I'd also like to vary the pockets that the sand falls in but it seems that all I have available to me is based on slope or elevation.  I suppose I could use a simple shape shader to limit where things fall but I was hoping to find a more procedural approach so when I'm done with this particular vista I can wander around the landscape and "take pictures" of other parts as well without having to retool the new camera location. 

I have to say that masking different types of topology, be it the rocks themselves, the sand that flows over them, and even the fake stones is proving challenging.  I'm trying to think of this like a compositor and lay things down in a logical fashion.  Is it better to work from the "ground up", where your lowest levels of the terrain are at the top of the flow and subsequent rises are added as you work down closer to the planet or would one work the other way, establishing the large structures first and then sort of carve out the ground level detail as you move along?  I've done it both ways here and it seems that both approaches have their pluses and minuses. 

Anyway, here's where I'm presently stuck.  I can't get the sand ripples to ride over the base rocks without also adding the same ripples to the base rocks.  Any insight would be mucho appreciated. 

thanks

-greg

[gregtee]

Dune,

That almost looks like the profile I want for the sand ripples...


Interesting.

-greg

[gregtee]

wiwine, that looks exactly like what I want.  My kingdom for something I can study that does that.

-greg

[Kadri]

Greg did you try to use the merge shader? It does have many possibilities.

And one more basic thing is if you don't want that one feature influences the other one at all
you can use two planet objects (for limited places in the landscape you could use displaceable plane object etc).
One for the rocks and one for the sand etc.
Not sure about render times i haven't used this method.
You could then put some lower scale displacement for rocks,sand
in which planet you want by copying the same nodes and lowering values etc.

[dorianvan]

Looking really good Greg, better with each one.

[gregtee]

Thanks for the compliments. 

I have used the merge shader with some success but the trouble start when I get to the second tab over with regards to how the shaders should be handled.  There's Mix, Add, and then a bunch that don't seem to be what I'm looking for.  What I think I want is an Over operator.  Mix I think of as a blend, add is additive, which I don't think I want, and the others don't seem to make a lot of sense for what I want to do.  What I think I want is for the sand ripples to sit "over" the rock floor, not become additive to the floor.  I don't want the ripple displacements to also add ripple displacements to the rocks.  This is why I'm wondering if I'm going about this wrong from a build up perspective;  should I grow the main rock structures out of a sandy floor base, or should I start with the rock structures and then layer the sand around  them? 

I'll need more time to think about it.

-greg

[Dune]

These are the kinds of issues a lot of us (me too) are pondering about and experimenting. I don't really recall if I got that solved (ripples also in stones). One idea is that you might need to reduce the size settings in the displacement intersection tab. It's basically at 2/-2/2 or something, but if you reduce the first to a millimeter or so, the second to minus 1 and the third to small + you can see changes occurring. That might help.
The thing Kadri mentioned should work also, I did that too several times, and doesn't add much in render time (not in my case at least), but you most liley get a sharp distinction between the two planets layers. Needs playing around a bit, I guess.

[Tangled-Universe]

Hi Greg,

To have sand "over your stones" you need to change the order of the shaders probably.

There's probably 2 ways of fixing this and always takes a bit of play to figure out what works best. It really depends on how much displacement you have going on and how many times you are compute the terrain already.

First way is to have your fake stone layer and connect those as a child to a surface layer.
Set the surface layer's smoothing to 1.
This will use the render state of the first compute terrain node up in the network from that surface layer.
It allows you to cancel out displacements for those stones and displace them separately.
Then add your ripples.

Second way is to have fake stones first too, then compute terrain with small patch size, then add your ripple layer.
This will probably be pretty slow to render!

If you look up some of my canyon renders you can see I managed to get it to work.
If you like I can dig it up and have a more exact look.
First let me know how it goes with these 2 suggestions.

Cheers,
Martin

[Chinaski]

Yo!

Not sure of what exactly is your problem here, but if you want to do something like that :



... check this file


It's on TG2 (because TG3 don't run on my computer), but, I think, It could work well on TG3.

Really nothing complicated here...

Just 4 things :


1 - The merge of the 2 textures is done with a merge shader (option Choose by altitude : Hightest). This shader can break if you have lateral displacements (on TG2, I don't know for sure on TG3)... You can solve this problem with a simple trick... Delete the merge shader and apply your second texture on an other plane (or planete, or whatever)... We do it with lakes, so why not...?


2 - If you want your sand to follow the relief you must use 2 instances of the same relief... On this file the nodes "TERRAIN HARD" and "TERRAIN SMOOTH same seed and size than TERRAIN HARD" are the same, except the second one is smoother.

You could also do that by using a surface shader with smooth option ON (0,5 or 0,75 value).


3 - Because of point 1 issue, warp on your sand isn't necessary a good idea. So I prefer to use a vector deformation ("VECTOR TO POSITION" group). Also you can use that to "elongate" your dunes.


4 - After that you add fake stones and plants, and your good. I hope this could help. And nice work!

[gregtee]

Thanks Martin and Chinaski, I'll take both your suggestions and give them a try. 

-greg

[gregtee]

Here's Chinaski's nodes just plugged in as ingested into my script.  Overall they're working, I just need to get the scaling working better and adjust the shapes and overall surface properties.  I am wondering why they're also displacing the underlying rocks in the foreground, I'll have to see where that's coming from. 

Since I don't know a lot about the blue nodes and this is almost an entire blue node setup it's going to take some time for me to figure this one out!

thanks again

-greg

[Chinaski]

Sorry, was longer than expected (I hate my PIII)

So, this time no more merge shader (by the way, on your last render, and if I must guess, I'd say it's a merge shader issue, something broke it)... I work on two differents planes, try dunes tweaks, and add some fake stones and vegetation. I also made bigger displacements ; This way you can see that the sand follow the relief and "jump" on the rocks.

I think the last one is the simpliest, and the best one for reverse engineering.







Tired. Sleeping.