After publishing my latest render “Morning After the Rain”, I’ve received some questions regarding the atmosphere in the scene. How to make a misty after-the-rain atmosphere? Thanks to Vue’s complex and detailed Atmosphere Editor, there are several ways to achieve such an effect. In this post I’m going to show you how I created the mist in “Morning After the Rain”.
If you like hiking in the mountains or if you’re lucky to live in the mountains with your window facing to a large valley, you must be familiar with the amazing sight of thick fog and misty puffs while and after raining. When I visited Hallstatt in the Austrian Alps with Michel two years ago, I had the chance to take some reference photos of such an atmosphere. Though it was not in the morning but in the afternoon, on the photo below you can see similar fog and mist as in my scene .
Though we can create an overal foggy look by increasing the Haze & Fog Density, and perhaps the Aerial Perspective in the Atmosphere Editor, there is a much more accurate way of making such an atmosphere. Before running into the details, I have to tell you that this method is more resource-hungry and – though there are tricks to make it faster – it’s significantly slower to render than if we simply increase the Fog or Haze density. It definitely gives a better result, but it might not be a best choice for animations (unless you have an unlimited budget for rendering).
Let’s take a quick look into the scene itself:
As you can see, the scene is pretty simple; we have a foreground terrain with HQ xFrog conifers, and a large-scale, complex terrain created in World Machine and GeoGlyph (great job, Dax!). The ecosystem on the mountain is not visible on this openGL screenshot, since it’s set to dynamic to save resources. The Sun is rising behind the mountains, nicely illuminating the fog, giving a dramatic effect.
And this is my way of creating this atmosphere. The scene has two – heavily tweaked – cloud layers; a low-altitude, higher layer of fog, and another cloud layer (Mist puffs) at a slightly higher altitude and much less height. Basically, we have a cloud layer within a cloud layer. Let’s have a look at them in the Editor.
The atmosphere I used as a starting point was “Morning Hours”, a photometric atmosphere included in our product “Hot Days in the Desert”. I deleted the cloud layer in the original atmosphere, and first I added the Fog.
Such a fog layer can be created from basically any Spectral 2 cloud that ships with Vue. If you want to use one of the default Spectral 2 clouds, the thick cumulus and stratocumulus layers may be the most suitable. This cloud layer is based on a Simple Fractal with Perlin Noises/Gradient noise pattern. The altitude is set to really low (75m), but the height (644m) is high enough to cover the entire area and to block the Sunlight. The Cover and Density values give you more control than the simple Fog Density in the Sky, Fog & Haze settings, and by tweaking the Feathers, Detail Amount & Altitude Variations, you can get a more complex, more realistic and less uniform look.
Since this is supposed to be a fog layer, all Lighting options (Internal shadows, Cast shadows, GI ambient lighting and Force ambient color) in the Lighting & Effects tab* can be disabled. They are not needed to achieve the effect we want, and they just further increase the render time.
*You can find the Lighting & Effects tab by double-clicking on the cloud material preview window, or right-click >> Edit Material.
The settings of the Mist puffs cloud layer are the following:
The density population of this cloud is controlled by a Fast Perlin Fractal. As a starting point, I used AsileFX’s Stratus 19 cloud, but Small Cumulus or Flat Cumulus from Vue’s default collection could also do the trick. You can see that the Height of this layer is way less, the Cover value is less, but the Density is a lot higher than the Fog layer’s. That’s how the mist puffs pop out. For better results and less flat-looking puffs, Internal Shadows was enabled in the Lighting & Effects tab. If you want even more accurate results and if you have enough resources, you can also enable Cast Shadows, but in this scenario I didn’t find it that necessary.
It’s important to mention that with the settings of the cloud layers above, Volumetric Sunlight needs to be enabled in order to get the best and most accurate results. However, if you have lower computer specs, or if you just want the scene to be rendered faster, a good alternative option is Projected Shadows on Clouds. You can find these settings at the bottom of the Sky, Fog & Haze tab.
So, this pretty much covers how I made the fog and the clouds in this scene. I hope you guys enjoyed this QuickTip, and I hope you’ll give it a try someday!
Good luck in creating your own virtual nature!