Author Topic: Push vertical surface in  (Read 1512 times)

Offline N-drju

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Push vertical surface in
« on: January 02, 2019, 05:14:21 PM »
Guys, I need your kind advice.

Attached is a screenshot of what I would like to do. I have a gently curved rock wall. Mid-height, I would like to indent this wall so that a small, narrow path is carved into said wall.

87097-0

I tried to make some adjustments using the surface shader's altitude limits, but that's not enough. Looks like I forgot how nodes should be arranged for a lateral displacement magic.

Now, I consider either a Surface Shader-masked twist and shear shader or a displacement vector to achieve the said push effect, but if you have some better ideas I am all ears and willing to learn. :) Thanks.

And by the way - have a healthy and creative year 2019! :)
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Offline cyphyr

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Re: Push vertical surface in
« Reply #1 on: January 02, 2019, 08:11:29 PM »
Something like this?
:)
You could use several with different displacement values at different levels for a more interesting effect ...
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Offline N-drju

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Re: Push vertical surface in
« Reply #2 on: January 02, 2019, 08:20:23 PM »
Uh-huh. That's what I am aiming for, but it's a real pain in the back!

I put to work, what Oshyan once gave me in that other thread (where you also waged in) and the "shelf" in the wall can indeed be made this way with lateral displacement:

https://planetside.co.uk/forums/index.php/topic,24082.msg255467.html#msg255467

But you know what the trouble is? I need that shelf to be very, very narrow. Not more than 5 meters wide. I can't seem to control it in any way... It seems that the cavern formed by lateral displacement is stuck at 30 meters deep and I turned my computer into a heater just to try and adjust it! :-\
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Offline cyphyr

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Re: Push vertical surface in
« Reply #3 on: January 02, 2019, 09:20:05 PM »
Compare with this one. Here the inset is only 5m but I have also reduced the falloff on the min and max height limits.

Another alternative method that may help is to use a Strata and Outcrop shader with 1 octave and octaves set to 1. Set the hard layer altitude to your desired height. See v3
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Offline Dune

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Re: Push vertical surface in
« Reply #4 on: January 03, 2019, 06:47:51 AM »
would probably use a surface shader/distribution shader with altitudes sharply set and a vector displacement shader with a single white as input. You can control the angle pushed in.

Offline N-drju

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Re: Push vertical surface in
« Reply #5 on: January 03, 2019, 07:21:35 AM »
These are good ideas and work to some extent but I still cannot nail one thing - I would like the "ceiling" to extend slightly beyond or exactly match the edge of the shelf below.

In your example Ulco, The upper edge of the indenture could be extended in order to form an overhang. This is what I also attempt. I tried to do it through an altitude-based displacement offset but the result is somewhat poor...

Alternatively, I also thought about using an elongated SSS and curve it with Redirect just like I did with the main terrain but it will be hard to control and adjust.
« Last Edit: January 03, 2019, 07:23:39 AM by N-drju »
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Offline Dune

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Re: Push vertical surface in
« Reply #6 on: January 03, 2019, 09:20:29 AM »
For an altitude based displacement offset, you need a compute terrain. If you use redirect or vdisp, you won't. I like to do as much without compute terrains. You could set a minimum altitude as in my example (but as high as the max altitude for the dent) on another surface shader and have it vdisped out. Perhaps just locally, by masking it by big soft SSS.

Offline N-drju

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Re: Push vertical surface in
« Reply #7 on: January 03, 2019, 05:11:06 PM »
Guys, I just played with both of your setups, but there is one significant problem that needs to be solved in Ulco's suggestion...

When I try to make a Surface Layer altitude-based shelf with a small (30 cm) fuzzy zone, what I get are these ugly transition zones on my mountain path:

87114-0

Of course I plan to add pebble and rock debris to cover it up but it looks very shabby anyway... Is there a way to smooth it over?
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Offline N-drju

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Re: Push vertical surface in
« Reply #8 on: January 03, 2019, 05:38:13 PM »
And while we're at it, do you guys have any suggestions on what should I do with the noise flavor of the lateral displacements (which I also use) on the planned rock wall? For now, they look like a complete columnar nonsense...

87116-0

Ahhh... Forget it. I get columnar displacements because I use "compute normal" instead of "compute terrain". :)

To be honest, I have a very scant knowledge regarding "compute" nodes, what they do and how patch sizes affect the terrain networks.
« Last Edit: January 03, 2019, 07:49:33 PM by N-drju »
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Offline Dune

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Re: Push vertical surface in
« Reply #9 on: January 04, 2019, 06:04:43 AM »
You probably need to mask out the path for those verticals. And what I know about computes is that patch size makes some average, so the larger the faster and also rougher. In this case a small patch size would be good. If you want big terrains with large smooth snow fields a very big (50-100m) patch size often does wonders in displacement intersection.

Or get my mountain road setup at NWDA, which can do that with some adjustments  ;) I just happen to be making some U-shaped gully mountain path with some overhangs.

Offline N-drju

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Re: Push vertical surface in
« Reply #10 on: January 04, 2019, 07:06:35 AM »
This vertical problem is no longer valid. Crossed-out as you can see.

But if you have some suggestions on what to do with this nasty, fuzzy zone effect on the path itself it would be nice. :)

I actually experienced this before when masking "twist and shear" by altitude. These transitions happen each and every time...
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Offline Dune

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Re: Push vertical surface in
« Reply #11 on: January 04, 2019, 08:26:44 AM »
There are some new settings regarding fuzzy zone computation, you might try to see if they do anything. And instead of color adjust use a smooth step (softer edged), but perhaps that's not used here.

Offline N-drju

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Re: Push vertical surface in
« Reply #12 on: January 04, 2019, 08:50:01 AM »
There are some new settings regarding fuzzy zone computation, you might try to see if they do anything.

What do you precisely mean?

As far as the path is concerned - you mean replacing "constant color" with "smooth step" as a vector function, yes?
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Offline Dune

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Re: Push vertical surface in
« Reply #13 on: January 04, 2019, 11:04:24 AM »
In the surface shader's effects tab; fuzzy zone better color... but I don't know if that would help.
And no; I mean if you need a colr adjust it's sometimes better to use a smooth step, as that has smoother transition. If you use a get altitude and want to have a soft zone, I'd prefer a smooth step.

Offline N-drju

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Re: Push vertical surface in
« Reply #14 on: January 04, 2019, 08:00:35 PM »
After all, I decided to use a completely different approach to achieve what I want. Not because I don't know how, but because it seems easier and more controllable.

I made another SSS-masked surface shader to make the path. I made it a bit wider than the main elevated terrain, so that a 3-5 meter path is created all along the wall, then, I'll just curve it like the main wall with the same exact redirect that I used for the larger structure. The good thing about SSS-masked terrains is that they are always smooth as long as they have an edge profile. Even if it's just a few centimeters...

An overhang can be conveniently made with a well-masked lateral displacement and I will add it too.
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