Clouds As Haze Test

[efflux]

The whole sense of atmosphere and space (or lack of) in my TG2 renders is bugging me so I'm experimenting with it. I want to have atmosphere and exposure blowout problems as with a photos and post editing but I don't want to lose the sense of space.

Looking through the Planetside Gallery I notice that usually the most successful images have good atmosphere. Some have cool features but are let down by atmosphere.

It seems that the haze glow can spoil the sense of space by glowing to much near the sun and be dull further away if the glow is turned high. I also wanted haze to be thick near ground. If you use it for this and it's too thick and glowy, it looks wrong. The settings in this render are Haze density 20 but Haze expo height 50. Glow is around default but I'll be testing combinations.

Allowing the haze to deal with what's going on low down left the higher atmosphere needing work. For this I used clouds. The settings of the density are in the screenshot. These clouds cover from ground to 1000s of metres up through the main clouds. They subtly change density in places. I don't know if my fractal set up is the best option it's just what I used first. Initially I was using it for "dust" hence the name. There are some holes but it's unlikely you'd find them. You could tweak contrast and coverage further. This setup creates great sun rays that vary slightly depending on the cloud thickness (generally what you often find in reality) without having to use thick haze which is very even.

The last image is my first test showing a render with clouds and haze density of 0 then quite thick clouds to create haze (way too thick in this one). Using only haze for thicker atmosphere from ground right up to above clouds has a tendancy to be too even.

I'm not sure what this will look like from other POVs i.e. above clouds but I'll test that.

[Chinaski]

The first render is superb!

I'm using basically the same technique (with less success), from time to time (because of render time issue). First that was for dust clouds on my numerous mars renders, and after that I used it sometimes to tweak the atmospheric perspective. Only notable difference: I generally use slightly bluish clouds.

An other trick is to use several atmosphere (with differents settings) on the same planete. This way you can have a "more progressive" haze, and play with the layers of blue sky.

[efflux]

Yeah, it's definitely a good idea to play with these things and it's very good to experiment with the various colour choices you have for certain things in the clouds but not just their basic colour. Clouds are rarely just white.

I expected render time problems with this but I found that if the clouds are roughness 0 there really isn't a bad impact at all. There could be when rays get involved. It rays like crazy in certain circumstances with this set up.

[TheBadger]

I know your just getting started. But I like these images already too. Something about vast open planes with giant sky and clouds that speaks to some primitive part of me.
Love these places during the day, but could not think of a worse place to be on a moonless night.

[efflux]

I like these kinds of scenes a lot too but I could not get it right until now. I'm happy with this technique for big spaces. The terrain was kind of an accident. I just brought in a terrain I had knocked out and didn't think much of but it fits this kind of environment because of the wide plains. I'm imagining putting odd standing stones in this. Maybe even model a standing stone circle. Lots of small, gravel, sand and stones. It might also be a good start to try vegetation. Grasses for example. It will develop further. There are always more things you can do. Often ages after doing something I go back because I've found something that works. One environment grows out of another. That's the beauty of procedurals.

[efflux]

Here's another test. This time I used another low level cloud layer as mist or dust. Upper haze is cloud layer and atmosphere haze provides a little exponential haze that doesn't really do much beyond the hill height. Cloud haze is more subtle here and much deeper at about 4000m. Probably should be even more. Hills are about 400-500m at highest, I think. I don't find this impacts render times badly. It's rough clouds that do that. The main clouds here take the longest time to render. I'm basically trying to tweak it so atmosphere seems all one whole to give better depth. I should have chosen a different POV. Although this planet is not that interesting with these surfaces, the lighter ground areas have a bunch more smaller stones.

[TheBadger]

I like this one a lot! It maybe just a test to you, but it looks like its ready for a comp to live action to me.

[efflux]

Thanks. I'm happy with the way some things are looking along this angle. It seems to me that things are opening up in terms of a feel of space. That hill on the left looks quite realistic but it's the atmosphere in front of it that's doing that. There's not much going on in terms of it's surface. The low cloudy mist is working much better than when there is heavier atmosphere haze rather than cloud creating the haze. The clouds as haze is tying it all together in a very subtle way. It still needs more work though.

[jamfull]

It seems that this technique misses out on the bluing of everything by distance that happen (atmospheric perspective). Are you able to change the cloud color to compensate? Or are these tests separate from that effect?

James

[efflux]

I think it's the bluesky settings that effects the blue in distance. Haze could of course also be bluish. I'm not altering bluesky settings much yet. Haze is simply reduced in role to low ground. I'll be experimenting with everything in conjunction, I just believe that haze is actually being overused where clouds do a better job. However an exponential haze is quite normal. It's just that I'm making it much more exponentially extreme. This means you lose thickness higher up. I've never been happy with the sense of space in TG2. Interestingly I was reading on a thread somewhere just a few days ago where someone else said this, that TG2 was flat looking, lacking sense of depth and space. This may be due to generally over-atmosphering everything but in a flat way which is what I'm experimenting with but I'm not killing off the bluesky settings although I believe that can also be slightly tamed down. I'm actually still into having the atmosphere look quite thick and having things blow out like a photo, I'm just doing it differently with less all over glowing haze.

Having said all this, some places have claustrophobic thick atmosphere. The UK is usually like this but other places often have very clear atmosphere.

[efflux]

The strange thing is that I have Terragen old version scenes with very thick atmosphere and I'm quite happy with those. I believe that even although we had just flat clouds in Terragen, people were tweaking the atmosphere colours a whole lot more and using higher exponential haze. Probably also using the clouds in different ways. Covering the sky in various layers.

[efflux]

These are the problems I'm trying to get around. If you take the default atmosphere and want it clearer of haze you can reduce the haze density. This causes the atmosphere higher up to look too empty (especially when you can see into the distance - this is a problem I see is some renders) and you don't have much haze lower down even if you still want quite a bit of haze but very low down. If you increase the haze expo (by reducing it's height) you can get way more haze lower down but again you lose atmosphere higher up. The haze glow is also crucial and it glows nearer the sun. More or less haze increases or decreases this effect but it can be undesirably one way or the other. Bluesky density also effects the ground colour and you can't control that well so best to not tweak the density of that too much except if you want extreme effect. If you use clouds as haze you can use more exponential haze but the clouds are not exponential. What this does is to create a scenario where if you are very low to the ground, it doesn't have to be very hazy to make the upper parts of the atmosphere look hazy. Often a problem with haze is that lower down POVs can be in thick haze but higher shots very clear. If you control the haze expo more to provide only very low haze then lower POVs can be quite clear and it will remain quite clear higher up without losing the haze look - if you use clouds for that part.

[efflux]

Chinaski's method may be a good solution. I've tried that before but never persevered with it. The one difference is that having subtle changes in the haze can be cool when you use clouds.

[efflux]

I have some more render tests from a bit higher altitude but I want to improve this first. I think in reality haze rarely just goes into an upwards exponential and it's also rarely just flat whether it's air pollution or a natural haze say under clouds. Look at the second photo here:

http://en.wikipedia.org/wiki/Haze

That's the effect you will get if you use clouds.

[inkydigit]

I have been following this thread eagerly, Efflux... This is great, I remember trying some low level 3d cumulus I used to simulate a dust storm, but that was ages ago, and I was using an ageing g3 iMac!!! So I gave up due to the render times... After seeing this I am inspired to try this technique some more.... Thanks

Jason