Rough Guide to the Atmopshere Editor – Part 5 – Sky Tab

Part 5 of the guide relates to the sky tab in the atmosphere editor. All the renders on this page are at 800×600 and are rendered at Broadcast Quality.

The sky tab is a page that is only available in the Standard Model of Atmospheres. The default atmosphere is used and set to the Standard model, the result is as follows:

There are a number of settings on this page which will be worked through step by step with examples of how each affects the atmosphere.

Sky Colour map
The sky colour map is a colour map that controls the distribution of colour in the sky. The darker colour to the right labelled “Zenith” marks the area at the top of the sky, and the lighter area marked “Horizon” represents the lower area of the sky where it touches the ground.

To change the sky colour map, you can either double click on it to open the presents panel or right click then select “edit colour map”, in this case I will select the latter option.

To demonstrate the difference that changing the colours means I have selected fairly obvious colours, bright red and bright green.

And the result…

You will notice how the green does not meet the horizon. This is affected by the following settings so in order to keep the changes noticeable the colours will remain the same.

Colour Map Position on Sky Dome
The following settings determine where the colour map is positioned on the sky dome, each of the settings will be displayed with a number of renders at different settings.

Lowest Altitude
The lowest altitude determines where the sky map starts, the lower the setting, the earlier the sky map starts from the horizon.

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Notice how the light on the ground changes colour as the altitude increases.

Map Height
Map height expands the length of the colour map, so obviously the greater the height of the map, the larger the amount of colours towards the horizon spectrum you will obtain in your pictures. Scalar from 2 to 90.

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Sky Colour Map Distortion by Sun
This setting affects how much the sun changes the colour map. For this example the sun is facing the camera becuase it is required so that the changes made to the sky map can be seen.

When the setting is increased, the sky colour changes from the zenith colour to the horizon colour in the areas surrounding the sun. For example.

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Higher settings move the zenith colours further away from the sun. Turning the camera shows that this is not the same as purely moving the color map up and down as demonstrated in this 360 degree pan shot.

Fog in Sky
The fog in the sky determins the natural fading out on the horizon caused by atmosphere. Without it the pictures begin to look very unrealistic and blocky.

Thickness
The thickeness of the fog determines how opaque the haze in the background is. To demonstrate this fully, the max altitude of the fog will be set to its maxium.

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Max Altitude
The max altitude determines how high the fog will be seen. To demonstrate this the fot thickeness will be set to 100%.

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And thats it for the sky tab! Next in the series is the Clouds tab, for which there will also be Cloud Reference Sheets.