Rock sculpting?

Started by james adamson, January 18, 2020, 01:08:44 PM

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james adamson

Hi all.
I have created a sheer cliff and I wish to flatten off the top which is where my camera sits looking out over a mountain range. What I would like to do is precisely
flatten sculpt or arrange the features of the area before the cliff edge and around my camera. I have been through quite a few tutorials but cant seem to find anything that will allow me to affect point or position x will tool y. If that makes sense. 
Thanks in advance.
James.


WAS

Quote from: Kadri on January 18, 2020, 01:41:52 PMDepending on your scene there could be different ways.
Have a look at this for example:

https://planetside.co.uk/forums/index.php/topic,7548.msg80786.html#msg80786

Surprised this is never shared for Canyon Setups. Gives me plenty of ideas. Thanks Kadri, and Matt.

Dune

Instead of clamp I would use a smooth step for a softer edge. For a local flattened area I would use a softish simple shape (circular preferably), mask a surface shader with it, set surface shader to smooth (100% or slightly less if you want some terrain characteristics remaining) and use offset to raise the area again to desired level. With a fractal noise between SSS and mask input you can alter the SSS shape a bit (roughen it up). That's one method. You can use the surface shader to add additional displacements as a child to that local area.

WAS

Quote from: Dune on January 19, 2020, 02:02:08 AMInstead of clamp I would use a smooth step for a softer edge. For a local flattened area I would use a softish simple shape (circular preferably), mask a surface shader with it, set surface shader to smooth (100% or slightly less if you want some terrain characteristics remaining) and use offset to raise the area again to desired level. With a fractal noise between SSS and mask input you can alter the SSS shape a bit (roughen it up). That's one method. You can use the surface shader to add additional displacements as a child to that local area.

Great advise, that's exactly what I did in testing. Gives you more control and not a sharp edge (unless that's what you're after, but TG will have a big issue with any lateral displacement)

Dune

Well, you can of course displace laterally after that, just add a compute terrain/normal first. Or use fake stones set to world space.

james adamson

Hi Kadri.
Thanks for that link. I looked at the Get altitude solution. Very elegant but also equally obscure.
That coming from a more visual head than a maths head and I could see myself going off down a functions rabbit hole with that. Definitely
a useful peep at somewhere I would not have gone yet in my third month as a Terragen user.
Anyway here is a clearer picture of what I am trying to achieve. The first still shows the plateau I wish to sculpt. I want to make it smoothed rock worn flat by the wind I guess? That plateau is botched from a power fractal and a simple mask but seems also to be affected by the fractal terrain and simple mask from the default Terragen setup. I also had to put in negative values in the cliff displacent so I know I am doing something wrong here. Maybe that is where the get altitude function setup could come in handy? I will stop waffling. Heres is my script and a couple of stills. Still two. I would like to create tributaries or small rivers on the plain leading to a small inlet to left fo frame. I do not yet know of any way to limit water distribution other than height so any pointers in that regard would be great.
And I also only know how to limit certain shaders by simple masks. Is or are there other ways to get at the scene in a more forenseic way.
I.E fractal warp at location x even if x is only a few inches across?
Thanks in advance.

james adamson

Hi Dune. Only just looked at your response. Lazy on my part. It does look like a number of my questions could be answered here
and I will need to start again, not as though there is much to restart! So simple shape shaders can also do displacements?
I will be looking at you suggestions right now. And why would fake stones be set to world space? What would that achieve over the alternative?
Thanks peeps for your responses.
James.

Dune

I meant SSS as mask, but indeed, they can be used as displacement (second tab).
Fake stones hauled through a transform shader set to world space (final) will displace them laterally, without need of a compute terrain.

james adamson

Great. Thanks for the explanation Dune.

james adamson

Just wanted to say thanks again. Tried out those suggestions and it's working a treat.
Many thanks.
James.

WAS

Quote from: Dune on January 19, 2020, 02:19:02 AMWell, you can of course displace laterally after that, just add a compute terrain/normal first. Or use fake stones set to world space.

You misunderstand. Sharp edges and TG with lateral displacement doesn't work well. High probability of tearing and bad look

Dune


Matt

Quote from: Dune on January 20, 2020, 03:08:26 AMSharp edges?

I believe WAS was referring to the situation if you wanted to use the hard clamp instead of your smooths step. He wrote: "unless that's what you're after [a sharp edge], but TG will have a big issue with any lateral displacement [if there is a sharp edge]".
Just because milk is white doesn't mean that clouds are made of milk.

Dune

I see. Yes, that's why I always try to avoid really hard edges.