cloud follow terrain

[Dune]

Still something quite elusive, and I get the feeling I'm doing something wrong. So, a few questions about this: does the altitude offset input need a compute terrain, or an XYZ shader, or is a line straight off the displaced terrain enough? Or does it need conversion to a greyscale mask (possibly stretched in Y)? So, what is steering the offset?
And whatever I do to the fuction multiplier (10-2000), nothing changes, neither in V3, nor V2 clouds. Depth modulator works alright, that's not the problem.

[Hetzen]

Altitude offset needs a scaler input. So a displacement to vector will convert your terrain to a xyz value. Then use a length to scaler to convert that vector to a single  length value (use this method if you plan on using an altitude instead of just a y value.)

I'm not at my desktop to double check this. I tend to use blues to bypass this function in the cloud node.

[Dune]

That's fast, Jon, thanks a lot. Off to work again....

So, to decrease the effect, multiply scaler (by say 0.5 for half the effect), or to raise the clouds: add scalar, add vector 0/100/0, or add an extra displacement before converting? What's best practise?

[Hetzen]

Just caught me having a coffe in the sun.

The function multiplier sets the mid point of where the cloud node starts it's fall off to 0 at the top and base of the cloud. 0.25 and a large depth input will negate any fall off on top and base, ie the cloud will have a sharp cut off. The same thing can be achieved by switching off the taper cloud check box in the tweaks section.

[Dune]

Thanks, Jon. Digest and experiment....

[Hetzen]

The altitude offset works in meters, so if your mountain is 2000 m and you want your cloud to be a 100m above that then just add 100 to the length to scaler.

[Dune]

Yeah, I found that already. You won't even need a displacement to vector and length to scaler I noticed, just a displacement to scalar will do. And any additional scalar stuff after that nicely changes the shape (like add or multiply or power...). But another problem arises (n V2 and V3), and I couldn't get rid of it (tried clamping); 'snow' in the cloud that's pushed up. How to get rid of that?

Btw, it works more reliable with a stretched Y for the initial terrain.

[Hetzen]

Displacement to scaler will work most of the time. Depends on how much lateral displacement there is.

As for the snow, it could just be a quality setting you need to turn up, or there's something in the network that's causing it. Not sure on that. Jitter?

[Dune]

It looks like there's a tiny bit of 'scalar' left that's not pushed up, like a 0.01 color. I'll see what quality does.