SceneSkies documentation

SceneSkies is an addon for Blender . It allows you to quickly choose among a collection of skies and environments to serve as world backgrounds, and to tweak the colors of their different elements (atmosphere, clouds etc). This is useful to light your 3d scenes in Blender, and to give them context. SceneSkies supports Cycles only, not Blender Internal.

SceneSkies' included skies are different from most other HDR collections: they are truly spherical, not domes with black bottoms. They have a very high dynamic range of colors. Their colors can be tweaked element by element (clouds, atmosphere, and sun). They are made specifically for large-scale scenes and to be used as a horizon, so you will see mountains several kilometers away for instance, and nothing in the foreground. Some skies have a ground (mountains etc), and some do not, like on a gaseous planet. Some skies are taken from unusual places, such as above the clouds, or on Mars. Finally the same skies are available at multiple elevations of the sun.

This documentation is intended to be used both as a reference, and a step by step tutorial on how to use all the features. I assume you have a basic knowledge of Blender, but not much more, that means you should at least know how to use the interface, and know about objects, worlds, textures and materials. I will explain some technical aspects of Blender or general CG concepts that are beyond beginner level whenever necessary.

If you have any question or remark on SceneSkies or this documentation, do not hesitate to contact me.

Installation and maintenance

Upgrading / updating

If you are upgrading from the free to the full version, you must uninstall the free version first.

If you are updating from a previous version of SceneSkies, you should either uninstall the old version first, before installing the new one. Otherwise internal conflicts will arise within Blender. The second option is to enable the "Overwrite" checkbox (enabled by default), when you navigate to the addon zip file in Blender's file explorer. In either case, you may need to restart Blender if you experience problems once the new version is installed, to make sure nothing from the old version remains in memory.

Installing the addon

Download the addon from your online account . You should then get a single zip file. You don't have to extract it yourself or put it anywhere special on your file system, Blender will do it for you when you install the addon.

In Blender, go to the user preferences.

Display the Add-ons tab, and at the bottom click on Install Add-on from file...

Navigate to the zip file in your file system and choose it.

The addon is now installed in Blender. Make sure you see it in the list of addons, you can use the search box to help you find it. Enable the addon: check the little box next to it.

If Blender complains it cannot install the addon, most likely you are using an incorrect version of Blender (see introduction of this documentation). Another common problem is a corrupt downloaded file, you can use an archive manager program such as 7zip to check if it is complete, or re-download the file with a download manager that can use the provided checksum in the download section of your account.

A new panel has been created in the world settings. SceneSkies is ready to be used.

Uninstalling the addon

If later you wish to uninstall the addon from Blender, simply use the button for that. This action cannot be undone so be sure before clicking.

When you update Blender

After you update Blender itself, some disk cleaning might be necessary. Blender will copy all your manually installed addons (and other files that constitutes your overall Blender user profile) to a new folder on your hard drive. That includes large addons like SceneSkies. The old addons folder will stay untouched. So in order to avoid wasting disk space, I recommend you delete the addons of the previous Blender version. Before that, make sure the new Blender works as expected and you don't have to revert back to the previous Blender version for some reason.

Proceed with caution when you delete "internal" Blender folders. I'm only giving you hints here. In case of doubt, please refer to the official Blender documentation. I've been doing it myself for years though, and never had a problem.

To know where Blender stores SceneSkies, and therefore to know the location of any old addons folder you might still have on your hard drive, look into the addon entry, in the list of addons.

Using the skies

To load a sky, choose one from the list of previews, then click on the Set sky button.

Each preview is facing towards the sun, so you can better compare its elevation in different skies. You can also see the sky image resolution (12k means 12,000 pixels wide by 6,000 pixels high) and the sky file name.

By default color tweaking is disabled (the checkbox next to the button). The next section explains color tweaking. But in this section we concentrate on the simplest way to load a sky.

You can see the sky once it is set if you do a render, or if you change the viewport shading to rendered mode.

You can also see the background in the viewport in non-rendered mode by enabling the appropriate option.

No more sun lamps

You should remove or disable any exterior sun lamp that may exist in your scene, because now the sky is providing the lighting, and in a much more realistic way than a simple directional lamp.

Use filmic

The skies are intended to be used with the filmic color profile. Only filmic can accurately display them. They have a very high dynamic range, so the very bright spots in the skies, such as the sun, its reflections, and the clouds will appear completely white, or incorrectly (eg black). The colors are also generally too saturated and contrasted for a realistic look.

If you need to adjust colors, contrast and brightness, still use filmic, but instead play with the exposure (not gamma), filmic look (built-in contrast options) and post-production effects either in the Blender compositor or with an external image editor.

Sky rotation

A new control for the sky rotation appeared below the previews. Use it to change the orientation of the sun. You cannot change the sun elevation in the sky though. Most skies come in at least two sun elevations: 10 degrees from the horizon which corresponds to either dawn or dusk. And 70 degrees from the horizon which is about 11am or 1pm.

World datablocks

Each time you choose a new sky, a new world is created and replaces the previous one. The old world datablock is still present, simply not used anymore. It will be automatically removed though if you close and re-open the blend file. So if you want to keep a previous world, apply a fake user on it.

Here is the world material that SceneSkies has created for you. It's pretty simple, and should not be necessary to modify for most uses. Changing the sun power (default strength of 5) is better done with the scene's exposure setting instead. Unless of course you need to tweak the colors, then you should read the next section.

Tweaking the sky colors

If you need to change the colors of the entire sky, or of specific elements, like making the clouds darker, or the atmosphere a different shade of blue, then check the box Allow color tweaking and (re)load the sky. Several controls will appear below.

When you change the sky colors, if your goal is realism, then be subtle and don't go overboard. It's easy to have unrealistic colors, but it takes talent and moderation to have the desired mood and realistic feel, while having beautiful results. Especially watch out for colors that are too saturated.

To see the changes faster while you tweak the colors, you can temporarily reduce or disable multiple importance (512 is a nice low value). This Blender setting makes your scene much faster to render, at the cost of some initial computation each time the world changes. So don't forget to re-enable it once you're done with the color tweaking. I recommend a value of 2048 for the best compromise speed/quality.

The tweakable skies are in a lower resolution (mostly 8k) than the non-tweakable ones (mostly 12k), due to a behaviour that looks like a bug in Blender. If the viewport shading is in rendered mode and if you change the material of an object in the scene, for example its color, RAM usage skyrockets and it is proportional to the resolution and number of environment textures. So I had to stay at 8k to keep the higher RAM usage in reasonable limits. If this seemingly abnormal behaviour is fixed in future Blender versions, I will increase the resolution of the tweakable skies to the same as the simple ones.

The sun color

You can change the sun strength, and sun color by manipulating the amount of red, green and blue it emits. You also have buttons to quickly have random colors for different times of the day: dawn, noon, and dusk. The sun color changes the lighting of the sky and the 3d scene. Reset the sun to its default color with the corresponding button.

Here are examples of random dawn sun colors:

And here random dusk sun colors:

Changing the sun color is especially helpful with dawn and dusk lighting because the sun elevation is the same in both cases, but its color is the key difference to give the desired mood.

Compared to the other elements of the sky, the color of the sun has the greatest impact on the color of the whole scene, and therefore on its mood.

The atmosphere color

The atmosphere is the blue background. Sometimes you may need it in a different shade of blue, depending on the needs of your scene. To that end, you also have a control for the saturation of the atmosphere color, to make it more or less vibrant. You can disable the atmosphere completely by making it black.

The clouds color

For the clouds, you can control their strength, to make them lighter or darker.