I've been playing with Matt's mackerel sky and I stumbled across a setting that looks a bit like snow, at least in the air. So I added in another altocumulus layer, as the apparent source. See what you think.
That's interesting. I always thought that snow would have to be done in post.
Aren't they just 'tiny' clouds? Perhaps a low layer of (blended) cloud with the right (minute) settings and low quality would produce flakes as well, never tried it. Might try it in a minute...
---Dune
They are indeed just 'tiny' clouds. And if you can improve on this, please do Dune.
Here's my try.
This is a cloud layer at height 0, depth 2000 with the distribution pattern set to feature scale 0.1, lead-in 0.2, smallest 0.05 and a few tweaks in lighting.
It's a beginning. Near the camera it's not very convincing yet, but in the middle distance, cool.
Looks intriguing.
Looks good and is an interesting use of the cloud functions.
It will of course look more convincing if you added some 'fogging' - all those little flakes tend to look like fog after a short distance. In both images the distant landscape is too visible.
I think, with the proper use of clouds-as-fog (as mentioned above) and snow on the ground, this would look 100% real.
A combination of the two files plus the fog might be helpful. In any event, here's the clip file I used.
Fogging, and some noise stretch for motion blur? ;D
- Oshyan
The issue intrigued me and I went to work on it. Promising results.
---Dune
Very interesting. I'm doing a render now with fog and snow. It's taking a while, I'll post it as soon as it's done.
Some things on my mind while I wait for it to finish are these:
A distance shader could be used to fade snow into fog - after all, the "fog" really is just dense snow seen at a distance. That would give us clear snow "flakes" in the foreground and fog in the distance, nicely blended into each other.
Thinking about the stretching - with the same method and some considerable y-stretching one may be able to achieve rain. What do you all think?
Edit: Here it is. I actually did it again and disabled the fog - this is pretty cool without, and dense enough that you get reduced visibility in the distance.
I'm busy as well, here's another image. I used a distance shader, but got rid of it afterwards. Stretching the Y, as well as blending will get the 'showers'. It takes a lot of tweaking. Don't look at the landscape, by the way.
---Dune
The most realistic results so far have been from Dune and Falcon. I think Falcon's has the best one. I like Dune's also, but I think it would be better with the vertical turned slightly as if driven by wind.
About this thread, who would have thought this was possible? Could this lead to a procedural generator for weather? That would be a unique feature. 8)
Here's a high-detail render. Starts looking good, but I need to fix the snow layer a little and then the fake snow.
What I changed in this one is the density and fractals of the fake snow. My idea was that changes in the snow flake size are one of the reasons the picture lacks depth. So I set lead-in, feature size and smallest size to the same value. But it doesn't make much of a difference. Will have to think of something else.
Try to set the smallest and lead-in to 0.01 and the largest to 20000. I did, and that works quite nicely. And the contrast of the cloud fractals to 0.3 or so. I have another one rendering now.
---Dune
This is my last render for today, I think this is nicely coming together. I'll also attach the .tgd
I don't yet know what's causing the "white-out" to the lower right.
I'll try adding some of the snow pines that were just posted to the files section and render a nice snow forest tomorrow.
This is really amazing Falcon. Both of you have done some really cool work.
I'm glad that my little experiment has stimulated creativity on Dune's and Falcon's part! Interesting that one works better for far shots and the other for near.
This entire thread has been very creative. Great work guys!
Thanks guys :)
There can be other useful ways too maybe...
This is the very little changed same file but this time as stars . As you can see there are problems. But i am sure you can make this useful in some way.
I can not test it (i use the free TG2 ). But this can be a real 3D star field in move . Maybe with a little tweaking galaxies , nebula's too ? ;D
Kadri.
Kadri, add a distance shader to the cloud/stars. This can keep them behind the other objects.
@Kadri: Good idea
@Falcon: The whiteout is probably a denser part of your low lying cloud. Another seed might get rid of it...
The problem with the close snow (IMO) is that the flakes are so sharp, it doesn't really look real. That's why I concentrate on further away 'downpours' of snow.
---Dune
At second glance, I might take that last sentence back; depending on the filter you use it may look good after all.
---Dune
After stopping the 10th or so new render, what I can say is that this thing is highly sensitive to even minor changes in the parameters. Tune something up from 1.0 to 1.2 - boom, everything goes grey. Tune a density down from 0.1 to 0.05 and you don't get half as many snow flakes, you get almost none at all.
I have a promising image coming along nicely right now, but there are so many parameter changes I'd love to try, and no time to do it. Not enough CPU power, in fact.
This is a very interesting approach, though. I think I'll be trying a modification for rain (stretch in Y direction, more grey than white) next, as soon as this one is done...
Ok, here it is. Fake snow with trees. I kind of like this shot. It's not yet perfect, but it is fairly convincing snowfall.
The weather outside is frightening...
Giving this snow a shot. Working on the fog, coloring, and lighting still. Made with the free edition till I get Deep back, so for now, this is the best rez I can pull off.
Thanks for the TGD, Falcon. I did a bit of playing and I agree that the settings seem rather sensitive. The whiteout you mentioned in your last but one image seems to be an effect of the clouds bunching up in a narrow valley, because turning the camera away from the valley removes the problem. Unfortunately changing the seed, as Dune suggested, doesn't.
I came across another rather odd effect. I rendered the same scene twice, first at 800 x 640, then at 2400 x 1920. At the higher resolution, the "snow" becomes much smaller. See attached and in the next post.
The smaller snow.
I've just given this a shot myself on a new .tgd and I must say it's very good, far better than the actual flake object attempt I made.
For variation, I'm using a secondary fractal as a blend shader(scales=10, 1000, 0.1) to the first 'flake' fractal(scales=0.1, 0.1, 0.01). The good thing about that is that by using the warp feature of the blending shader fractal, you can 'twist' the pattern of the fake flakes to give some variation(and use different noise patterns), using the warp of the flake fractal has little effect on the flake distribution due to the tiny scales used in it.
This is all pretty cool and I'm playing with it now...
With the scales mentioned above ^^, here's a couple of different flake variations. The settings are very extreme between the 2 images, a very much closer incremental setup would give very nice animated snow...
Fractal blend shader - Warp = 0.5:
[attachimg=#]
Fractal blend shader - Warp = 5:
[attachimg=#]
And a basic .tgd(blending warp value = 0.5... [attachimg=#]
* There is no snow surface layers, it seems so thick on the ground because the centre of the flake fractal(500m depth) is at nearly ground level, I think. Off-setting the cloud height upwards would thin it out at the ground I assume, although this might be the same thing mentioned in previous pages with the whiteout issues. I think, though, if you raise the clouds to a higher level this would be resolved. ???
Probably. I won't be able to play with this anymore over the weekend.
Speaking of cloud height: Anyone know by heart if the cloud height is from the height parameter upwards only, or in both directions? Is the height parameter the center of the cloud layer, or the bottom?
Yes, it's from the centre, outwards.
Very nice addition, Dandel0. Snowflakes indeed often hurl around in patches. Did you try high res large and small renders to see whether the flakes are different in size? I find Domdib's find quite intriguing.
---Dune
I didn't try different res/sizes/etc, no. I actually only downloaded the free version for this computer last night, I'm not at home. I just had a quick play with this while my girfriend was in the bath. I'll play more when I get home... :)
*** Raising the clouds does remove the apparent ground covering of snow. I've just tested it and I found that the lower extreme of the flake layer(minimum altitude in the cloud settings), should be at about ground level to reduce the whiteout effect that is happening from being so far inside the cloud layer.
A detail level of '1', I imagine, will give the actual correct scales of the 'flakes' when rendered, the larger flakes at lower detail levels are due to not enough subdivision being done on the small scaled flake fractal.
raising the cloud layer solves the whiteout issue.
But detail 1 doesn't bring much difference. What I find kind of troubling is that no matter what I do, I don't get any closeup-snowflakes.
Here's a render with detail 1:
Perhaps an extra cloud with a larger cloud size? And restrict it to close-up by a distance shader...
---Dune
i used a cirrus layer to do this with quarter density just to leave enough light thru. I been playing around with this idea some time ago
http://www.terragen.org/index.php?topic=4791.msg38454;topicseen#new