SOA Clouds UE4
Documentation

VERSION 1.2 - JUL. 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

Changelog

UPDATE 1.2 – July 2021

READ CAREFULLY

The SOA CloudsMaker plugin has been rewritten from zero, for many reasons. This new version will give you better visual results and let me update it more often in the near future. I also deleted useless textures and features from version 1.1 in order to make the plugin lighter and easier to use.

Here some changes:

Whole new visual quality, with a brand multichannel volume texture for details. Size, Contrast, Bias, Offset values are now inside a material parameter collection, so you can track them in a level sequence to create animated scenarios. Details have now more options, like additional realistic details. Multi-layer clouds feature added (beta) with debugging values to better understand what’s happening. Height variations values now work properly to add differences under the clouds.

HOW TO START:

1) Open the test map in the SOA_CloudsMaker_v1_2 folder.
2) Go to the preset folder, open both the material instance and the material parameter collection to modify the shader.
3) Quality can be modified in the SOA_CloudsMaker BP detail panel.

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 50 Km (NEW!), 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 Mask

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.

UPDATE 1.2: You can modify “Main Shape Size” inside the “MPC_SOA_MasterCloud_v_1_2” Material Parameter Collection in /presets. 

1.3 Main Shape Contrast

This parameter will blur or contrast the cloud shape.

UPDATE 1.2: You can modify “Main Shape Contrast” inside the “MPC_SOA_MasterCloud_v_1_2” Material Parameter Collection in /presets. 

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.

UPDATE 1.2: You can modify “Main Shape Bias” inside the “MPC_SOA_MasterCloud_v_1_2” Material Parameter Collection in /presets. 

1.5 Clouds Tint

This parameter will affect cloud overall color.

1.6 SSS Tint

This parameter will affect cloud subscattering color.

1.7 Cloud Top Bias

This parameter will affect cloud top part, squeezing it down.

1.8 Clouds Density

This parameter will affect cloud transparency. 

UPDATE 1.2: You can now turn on a secondary noise for density with “Density noise opacity”. This will allow you to define a min and max density value.

 

2. 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.

2.1 Details Volume Texture

The NEW MULTI-COLORED 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.

2.2 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.

2.3 Details Size Multiplier

This parameter change the overall size of details in the clouds. If you need, you can modify Details Big, Medium, and Small one by one instead.

2.4 Secondary details

This parameter modifies the number of secondary details in the clouds. These details will be subtracted from the default ones.

2.5 Additional clouds

Increase this value to add clouds outside the starting main shape.

2.6 Details fringe contrast

This parameter changes the contrast of the cloud details fringe.

2.7 Details offset bias

You can use this value to synchronize the details and main shape movements.

2.8 Details Z scale multiplier

This parameter scale clouds on the Z-axis to make them look more realistic.

3. Wind

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.

3.1 Wind multiplier

Increase the overall speed of the entire cloud system. You can also modify x, y speed with Wind Speed X and Y. Wind speed Z is a placeholder, not working right now.

3.2 Details Speed multiplier

Increase only the details speed to generate different effects.

3.3 Use Turbolence

This parameter activate/deactivate turbolence (the old noise)

3.4 Turbolence amount

This parameter change the amount of noise.

3.5 Turbolence tiling

This parameter changes the noise size.

4. Height Variations (HV)

SOA CLOUDS MASTER MATERIAL

In this panel, you can: 1) modify the clouds bottom pushing it up with a heightmap; 2) Blur the clouds bottom texture 3) Change its speed.

4.1 HV size

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

4.2 HV amount

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

4.3 HV Contrast

This parameter will contrast the  “Height variations” texture.

5. Layers (beta)

SOA CLOUDS MASTER MATERIAL

In this panel, you can: 1) modify the clouds bottom pushing it up with a heightmap; 2) Blur the clouds bottom texture 3) Change its speed.

5.1 Clouds layers

This value set the number of cloud layers. Ex: 1 = 1 layer, 2 = 2 layers, 3 = 3 layers… 

5.2 Clouds layers bias

This value changes the height of every cloud layer, squeezing them up or down.

5.3 Layer wind multiplier

With this value, top layers will move at a different speed.

7. Vertical bias

SOA CLOUDS MASTER MATERIAL

A few options to modify the overall vertical shape of your clouds (MODIFYING THIS IS NOT RECOMMENDED)

7.1 Lower Bias & Falloff

Lower falloff curves the bottom part of your clouds.

7.2 Upper Bias & Falloff

Upper falloff curves the top part your clouds.

7.3 Upper Contrast

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