SOA Clouds UE4
Documentation

VERSION 1.1 - JAN. 2021

Welcome to the online documentation for the SOA Cloud Material Pack for Unreal Engine 4.26. If you need any help, please don’t hesitate to contact us through the contact form. You can buy the project at this link on the Epic Marketplace.

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SCREENSHOT FROM UE4

List of contents

0. Volumetric Clouds
0.1 Layer Bottom Altitude
0.2 Layer Height
0.3 Tracing Start Max Dist.
0.4 Tracing Max Distance

1. Main Shape Panel
1.1 Main Shape
1.2 Main Shape Size
1.3 Main Shape Contrast
1.4 Clouds Bias
1.5 Clouds Density
1.6 Clouds Speed

2. Height Panel
2.1 Height Differences
2.2 Height Differences Size
2.3 Height Differences Contrast
2.4 Lower Falloff
2.5 Upper Falloff
2.6 Falloff Contrast

3. Details Panel
3.1 Activate Details?
3.2 Details Outside Clouds?
3.3 Details Volume Texture
3.4 Details Amount
3.5 Details Size
3.6 Details Contrast
3.7 Details Speed
3.8 Wind Speed

4. Extra Noise
4.1 Activate Noise in Details?
4.2 Noise Opacity
4.3 Noise Size
4.4 Noise Speed

5. Quality & More
5.1 Map Mips
5.2 Global Multiplier

Changelog

Update v.1.1 – January https://youtu.be/xJwWU4Y5maw

  • Better looking clouds
  • One extra level of details
  • New test scenes
  • More textures & presets

Before to start...

To use the SOA Clouds Material, a SOA_CloudsMaker Actor is needed in the scene.
Read below a few things about it and new options in the DirectLight (sun) actor on clouds.

SOA_CloudsMaker Actor BP

VOLUMETRIC CLOUD PANEL

The SOA_CloudsMaker Actor BP  is an objects you can place in the scene, (it works within UE4.26). It creates a realistic and fully functional cloud system that reacts with natural light. Inside it, there’s a VolumetricCloud component that use a the SOA_Cloud material to generate a result. It also provides you controls to change the quality/performances of the cloud system.  In the Details panel, you can anyway modify a few key options:

0.1 Layer Bottom Altitude

The altitude at which the cloud layer starts (Kilometers above the ground). If you change this parameter, the clouds’ bottom part will move up and down. The lower limit is 0, the ground, but it’s too low.  I suggest you start at 1 (Km).

0.2 Layer Height

The altitude at which the cloud layer ends (Kilometers above the ground).  If you change this parameter, the clouds’ top part will move up and down. The top limit is 20 Km, which will generate a very high (and probably dense) cloud system. I suggest you pick a value depending on the clouds you want to generate.

0.3 Tracing Start Max Distance

The maximum distance of the volumetric surface before we accept to start tracing (in Kilometers). Volumetric clouds create clouds around a sphere (like a planet). Changing this value will modify the visibility of clouds close to the horizon. If you have an ExponentialHeightFog actor, you’ll probably lower this value to around 120.  

0.4 Tracing Max Distance

The maximum distance that will be traced inside the clouds (in Kilometers). This value modifies the visibility of clouds from where you are. Lowering it will probably hide clouds, so keep it as it is. I would lower it only if you’re surrounded by mountains that limit the overall sky visibility.

1. Main Shape Panel

SOA CLOUDS MASTER MATERIAL

Once you placed a VolumetricCloud actor in the scene, you will need a material to plug-in in into its Material tab. You can try to make your own, right-clicking on the “M_SOA_MasterCloud_v1” master material, selecting “Create a material instance.” Otherwise, you can use a preset from the folder and modify it as you want. Down below, you can find all the settings available in this version.

In the Main Shape panel, you can modify the cloud’s primary form. Imagine it as a black and white map, extruded on the z-axis.

1.1 Main Shape

The cloud main shape mask is a black and white image. White areas will be extruded to create the main volume. Black areas are not visible. You should experiment with different types of maps and shapes.

1.2 Main Shape Size

This parameter changes the size of the main cloud shape. Long story short, this will modify the scale of your clouds. If you exaggerate, clouds may look very far away.

1.3 Main Shape Contrast

This parameter will blur or contrast the cloud shape.

1.4 Clouds Bias

Like a threshold, the cloud bias parameter will increase or decrease the presence of the volumetric clouds. You can quickly switch from an overcast sky to a clear one.

1.5 Clouds Density

This parameter will affect cloud transparency. Remember that clouds, like fog or smoke, become transparent as you pass through them. If your clouds are very thick, going down with density too much is not a good idea.

1.6 Clouds Speed (X, Y)

With Cloud Speed X and Y, you can move the main cloud shape to the north (Y+), south (Y-), west (X-), or east (X+).

2. Height Differences

SOA CLOUDS MASTER MATERIAL

In this panel, you can: 1) modify the clouds top pushing it down with a heightmap; 2) Blur the clouds top, or bottom, to soft them up.

2.1 Height Differences

The texture will be subtracted from the top of the clouds. Try different maps to achieve new, interesting results.

2.2 Height Differences Size

This parameter will change the “height differences” texture scale.

2.3 Height Differences Contrast

This parameter will contrast the  “Height differences” texture.

2.4 Lower Falloff

Lower falloff curves the bottom part of your clouds.

2.5 Upper Falloff

Upper falloff curves the top part your clouds.

2.6 Falloff Contrast

If you contrast the falloff, clouds will taper in on the top, or bottom part, depending on positive/negative values.

3. Details

SOA CLOUDS MASTER MATERIAL

As the title said, you probably want to add details to clouds now. This is done by subtracting a volumetric texture.

3.1 Activate Details?

Choose to activate details or not in your clouds. This will improve visual quality at the cost of shader complexity. This material is not highly optimized for videogames yet but it works well for archviz purpose.

3.2 Details Outside Clouds?

Details could stay only inside actual clouds or going outwards. Be careful; if this option is true, you may override the original cloud shape.

3.3 Details Volume Texture

The volumetric texture to generate details. You can find them in the texture folder. The SOA Clouds material use volume textures made from 8×8 flipbooks, with 512 px wide atlases.

3.4 Details Amount

This parameter modifies the amount of details in the clouds.

3.5 Details Size

This parameter change the size of details in the clouds.

3.6 Details Contrast

This parameter changes the contrast of the volumetric texture used for the details.

3.7 Details Speed (X, Y, Z)

You can change the speed movement of details in the three-axis. This means you can also move details from the bottom to the top.l

3.8 Wind Speed

This parameter is an additional way to move cloud details.

4. Extra Noise

SOA CLOUDS MASTER MATERIAL

To add an extra level of realism, you can activate this noise to warp the cloud shape to look like it is moved by wind.

4.1 Activate Noise in Details?

This parameter modifies the amount of details in the clouds.

4.2 Noise Opacity

This parameter change the size of details in the clouds.

4.3 Noise Size

This parameter changes the contrast of the volumetric texture used for the details.

4.4 Noise Speed (X, Y, Z)

This parameter modifies the amount of details in the clouds.

5. Quality & More

SOA CLOUDS MASTER MATERIAL

A few options to modify the overall look of your clouds.

5.1 MipMaps

These parameters lower the resolution (in pixels) of the textures used. Zero is the original resolution; one will be half of it, and so on.

5.2 Overall Multiplier

The Overall Multiplier changes the size of every single “size” parameter in the material.