Snowscape

Started by Hannes, November 14, 2021, 10:06:28 AM

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Hannes

Like always this started as something completely different. I created a terrain in Gaea, textured it, liked it, found there could be a little snow as well, and finally made the snow the main character here.
Then I thought, there should be some sort of snow chaos in the air. So I played with a V2 cloud with very low quality (0.1) to get some grainy, flakey look. First, this didn't look good. Second, it took a lot longer to render than with higher quality settings, which sounds rather weird. ???
Eventually I remembered my own rain file here in the file sharing section, which is made of a V2 cloud:
https://planetside.co.uk/forums/index.php/topic,21035.msg210254.html#msg210254

I used it and then modified it (I made the density fractal stretch on the Y-axis, and then used a transform shader to rotate the fractal towards the camera). I tweaked it a bit until I was happy and additionally used a distance shader to avoid big white splotches directly in front of the lens.

At the moment I'm rendering an animated version of it. The camera flying over the landscape with the "snowflakes-cloud" having the same animation like the camera (attached to it, so to speak) and the fractal stretch rotated, so that it's always pointing towards the camera, giving the effect (hopefully) you can see, when you're driving in the car when it's heavily snowing.

Hannes

Here is the terrain without the "snowstorm". Unfortunately a lot of detail got lost by adding the storm.
Something else: after I created the terrain in Gaea, I realized that I hadn't created a snow mask. I didn't want to start all over again, and so I made the snow distribution in TG. I found that using two white shaders, one using "intersect underlying" (plus a compute terrain shader before to adjust the detail), and another one with a slope constraint both in a row makes a quite natural looking snow distribution.

Dune

Very cool, seriously meant. Especially with the snowflakes, a very realistic effect! Looking forward to the animation!!

Hannes

Thanks, Ulco! This will take a while. Rendertime (800 X 450px) 35 minutes per frame...

WAS

Getting really good with Gaea, Hannes. Wow. These are great. Love the snowstorm idea. Came out great.

Dune

As an afterthought; might be cool (speaking of driving through a snow blizzard) to make the effect of a windscreen wiper. Snow gathering on screen (animated masking of a surface layer), then a mask wiping it off, etc. Should be possible. But I guess that needs a glass plane/card, and will increase rendertime due to increased subdiv.

Hannes

Thanks, guys!
Well, Ulco, this might be a very ambitious project! If the snow would be made of particles, I guess, this would be doable, but since it's all fractal spots, I have no idea, how to make these stay on the windscreen for a while and then to be wiped away by a windscreen wiper.
OK, if the flakes on the windscreen don't have to be exactly like those that hit the glass, I could populate the windscreen by some objects (like I did with grassclumps for rain). But wiping them away, while new ones are following?
Really a tough one!!! But worth a thought... :)

Hannes

OK, I read your thread again, and found, you already described roughly, how to do that... :-[

What I am thinking, is how to create masks that allow snow gathering on the screen for a while, being wiped away and instantly starting to gather again?
Of course everything could be done with image sequences, but I guess, we're talking about doing it more or less procedurally in TG.

Dune

I thought it would intrigue you. If you have a white dotty surface, it can be animated to be completer white or almost absent of white dots, perhaps by adjusting the coverage and breakup, and/or offset of the fractal. Should be no problem. Then a simple shape (rotated) to be animatedly rotated across the plane, multiplied to the former fractal/surface shader, or inversely masked, so the 'accumulating' whites are masked out completely. But there would need to be a cycle of the whites getting denser in accordance with the cycle of the simple shape being wiped across. Ambitious, yes, but doable I think.
A cycle can perhaps be done by multiplying something by the frame number.... I'm not very good at stuff like that.

It's a different thing than the particles.

Hannes

...I'll have to think about that! ;)

mhaze


Hannes