Sample Worlds Torn Apart - Sky Editor

The only feature of the landscape we haven't played with yet is the air. Go to the top of the Global Parameters and click on the cloud to get the Sky Editor. You've got Background, Atmosphere, and Cloud Layer settings to play with. Check out the Background (click on the angle to expand the parameter display).

The only thing you can do here is set the color.

[Calyxa butting in here for a moment - Oh my, it's blue. This is an old planet, isn't it. For the planet as-is, it isn't a problem, but if you add any moons, or perhaps when viewed from space, there may be, um, issues. Allow me to dig up some words of wisdom from Craig regarding the old blue simple sky:
However, if you set a sky color other than black in the simple sky, that shows through the night atmosphere colors, and blows out the background... Technically, it's totally correct, as your planet and moon are floating in a infinitely large glowing blue thing, so the moon will be black and the background will be blue...
Basically, what that amounts to is you won't get nice crescent moons, you'll get ugly circles that Don't Look Right. Use a simple sky color of black. I'm sure we'll revisit this when Chris goes through 1.1's 'default.mjw' because the sky there has stars in it, which come from a mostly-black texture. But I don't want to spoil too many surprises. So, back to Chris!]

View the Atmosphere settings by clicking on that little ">" symbol:

There are a lot more options with Atmosphere, but these are currently all set to plain constant values or colors. These can be manually adjusted by playing with the thumbwheels, entering values in directly, or for more variation, by changing the "widget" (the constant) to a texture. (Click on that half-circle next to a parameter to change the type.) For this particular world, we've just got simple constants.

The Cloud Layer is a bit more interesting.

There are two values that are really textures: Cloud Color and Density. (Of course, they could also be changed to just plain constant colors or values). Also note that the little circles for Cast Shadows and Receive Shadows are checked. Receive shadows is not really recommended; it can dramatically slow down any renders that have shadows enabled.

Click on the "t" to get the texture editor for the cloud color.

 
 

This is a simple Monofractal with a maximum size of 7000 meters and a scale of 1, so we are dealing with basic fractal output. The interesting piece here is the output control.

The output control consists of three parts, where when we've seen an output control previously, it had only one part. As with the output control of the terrain texture, there is a input curve. This texture also has a gradient and an output curve.

A note here about the one versus the three output controls - there are two types of textures: value textures and color textures. When a parameter's widget is a thumbwheel or other single-valued type input, any texture attached to that parameter will be a value texture and will have only an input curve in the output control. When a parameter's widget is a color swatch, any texture attached to it will be a color texture and will have the input curve, gradient and output curve in the output controls.
Check out the Gradient by clicking on the shaded box.

This is a color controller. The right-most color selecter or "knot" shows the RGB colors associated with the gradient value of .997; the gradient index values range from 0 to 1. (If you want to play with the colors, the three diamonds under the marker to the right turn off Red, Green, and Blue respectively, and by selecting a knot you have complete control over the colors at that point in the gradient).

Since the gradient runs from 0 to 1, this means the fractal values have to be constrained to this range. This is done with the input curve:

The Max/Min Input values are set to run from -1 to +1 (to cover the range of the fractal output), and the output values go from 0 to 1, which fits the requirements of the gradient. The lower left point is selected: notice that the input value is -1 and the output is 0. The input ranges should really be clamped, but it appears that values outside the gradient range are automatically stuffed back in, so clamping is implicit for this one.

The Output Control curve is slightly unusual.

It looks quite normal with a range of 0 to 1 and a linear diagonal, but notice in the upper right corner there are actually 3 curves. The output of the gradient is a color - with Red, Green, and Blue values. The curve editor contains three separate output controls, one for each color, which can be manipulated independently.

The other texture associated with clouds controls the density.

 
 

The basic function is, again, a Monofractal with a fairly large feature size of 50 km. The Output Control is not the normal diagonal, however:

The S-shaped curve will give "edges" in the cloud, where the density changes rapidly. The maximum output value is only about 0.5; apparently a higher value than this makes clouds that are too opaque. This is a matter of artistic preference; adjust to suit your mood.

This covers the settings in the "simple" MojoWorld, which are fairly understandable and a good introduction to how the controls work. The next piece: tear open the MW 1.1 default world and see what's different.

Part One sections:

Part Two sections:

Back to Generator Tutorials

Home