Varying min alt?

[blattacker]

Just a quick and simple question that no amount of Googling or searching through these forums has answered for me. Is there any way to get the minimum altitude for a surface shader to vary? I'm trying to make snowcapped mountains, but when I set a minimum altitude so that the snow doesn't go all the way down, it's just a straight line at that altitude with the fuzzy zone. I thought about using a painted shader to manually do it, but it starts to become really time consuming, and takes a lot of tweaking to make it look just  right. I'm just wondering if anyone has figured out an easier way to do this? I've attached the project I'm working on as an example. The dirt layer I did with the painted shader, and the snow layer shows the issue I'm having.

[Oshyan]

Use Fractal Breakup with medium-high scale values (e.g. 200-500 meters, assuming your scene is at real-world scales). Fractal Breakup affects your surface layer distribution more as coverage density decreases. So even if your surface layer is at 100% coverage, as it is blended out by the altitude constraint, its density will decrease and it will also be affected more by the Fractal Breakup, providing some randomness with appropriate scale settings in your Fractal Breakup shader. It also appears that your minimum altitude has a fairly small Fuzzy Zone, and you will need that to be bigger for best effect with Fractal Breakup (the Fuzzy Zone will be the distance, in meters, over which the coverage goes from the max value to 0).

- Oshyan

[Dune]

You can use a distribution shader for the height and fuzzy zone, and warp that in Y direction by a vector displacement shader, warp shader and power fractal. Thus, you can get an undulating 'line'.

[blattacker]

Alright, well, I tried Oshyan's method already, and I'm actually really liking the effect. I never really paid much attention to the fractal breakup, I never really knew what it was, hahaha. So here's what it's looking like so far, now that I have proper lines and stuff. I'm just working on trying to make it look actually realistic now (if anyone has any tips, that'd be great, but it's not really required, haha)

[Tangled-Universe]

You can use a distribution shader for the height and fuzzy zone, and warp that in Y direction by a vector displacement shader, warp shader and power fractal. Thus, you can get an undulating 'line'.

Yes that's also possible, but considerably more complicated compared to using fractal breakup only.
Actually, those undulating lines can be achieved by using a large scale fractal breakup.

[cyphyr]

Ok I'm getting complex now! (Now there's a surprise)
You could use a combination of both.  Using Dunes method and using the same PF as is used for the terrain could get the up and down of the snow line to follow a logical path (snowline rises on exposed bluffs and lowers on hidden valleys). Then the whole could be broken up with Oshyan's method giving a more natural  natural broken snowline ...
As I said "more complex" but it might be fun to try. (possibly not for beginners, yes that is a challenge!)

Richard

[Tangled-Universe]

Definitely an interesting approach and worth pursuing at some time.
I agree that for a less experienced user it's probably best to start simple by using Oshyan's suggestion and to see how to proceed from there.

[blattacker]

Thank you for all the replies! I will definitely try some of the more advanced sounding techniques on later scenes. It's a shame that there's not more tutorials for advanced stuff like that.

While we're on a roll, though, does anyone have any tips for making snow and dirt layers look like they're actually lying on top of the surface layer, instead of simple color changes? As in, at least with the snow, making it look like it's got some actual depth to it? (If this is a noob question that there is actually a tutorial for, feel free to point me in the right direction. I'm not sure how to work the question to search for it)

[Dune]

For thick layers of snow you might try the displacement intersection tab in the surface shader. Tick it and see what it does. There are files about snow on the forum, and if you're looking for more sophisticated presets, try the NWDA store. If I understand your query correctly, that is.

[Hetzen]

Here's a link I posted a while back. Looking at the title of the thread, I'm not really suprised you missed it.

http://www.planetside.co.uk/forums/index.php/topic,13236.msg132432.html

There's a clip file at the bottom of the page that creates this effect. It works in the same way as the altitude constraints in a surface layer, except you have a PF to adjust the luminence and scales to multiply the depth of the deviation from your chosen altitude and fuzzy zone.