Chaoscope tutorial
High quality renders
This tutorial will help you to get the best out of Chaoscope rendering engine. There's little amateur fractalists will learn from it because what applies to Chaoscope is also valid for most fractal software.
Finding the right angle
The first thing to consider before rendering is the view angle. Attractors are complex shapes by nature so changing the angle will have a dramatic incidence on the image composition. Some attractors also look better under certain angles, like highly chaotic Pickovers. This is a matter of personal taste and talent, but as a rule of thumb, the attractor should fill at least two third of the frame.
| fig. 1 : changing the view angle may affect the brightness distribution | |
 |
 |
| default angle | custom angle |
Changing the view size
 |
| fig. 2 : size is now 600*600, angle was slightly modified so the attractor aspect ratio is closer to a square. Iterations is the default 20,000,000. |
Your attractor may not fit the default 4/3 frame
ratio (if you decided to adjust) so the next step will be to
change the view size to match the attractor aspect. You can experiment with different
ratios like 1/1, 2/1, 3/2 or even the Golden ratio itself. If
you intend to print your creation and go for a very large size, the only limit to the size
is your available physical memory.
If the attractor doesn't fit within the view (high scale) you
will notice that pixels on the edges appears darker. If you want your picture to
have a specific size and trim the darker pixels off, increase
the height and width by 2.
Choosing the rendering mode
Depending on what you're trying to achieve you may want to try all five rendering modes. The Solid mode is a bit limited in 0.3, but it can be the better choice for some attractors. (i.e. in the gallery)
| fig. 3 : the five rendering modes, default iterations for all | ||||
|
solid |
||||
| gas | liquid | |||
| light | plasma | |||
Picking the gradients
| fig. 4 : light mode with custom gradients — blue to orange for speed, blue to red for angle — nice but dark. |
| fig. 5 : Same as fig. 4, Brightness=4 and Gamma=3. |
| fig. 6 : Same as fig. 5, 400,000,000 iterations. Notice how the noise almost completely disappeared. |
If you've chosen Light or Plasma as a rendering
mode, the next step is to pick the right gradients.
This is a long winded process, unless you have a favourite colour
scheme you want to apply to all your renderings. In some cases
Speed and Angle shades are equivalent (located on the same parts
of the attractor) so one gradient is enough. Loading the map
file named black.map will "switch
off" the redundant gradient.
Complex colour maps aren't essential, two colours for each gradient
is sometimes just what it takes. A good example is
which only uses red to blue for speed and green to black for
angle.
An alternative way of picking gradients is using the "Random Gradients" function, bearing in mind random
number generators artistic taste is reputedly limited.
First render
Once you're happy with view angle, size and gradients, you can start a first render with the default maximum iterations. Use this render to adjust the mode-specific parameters, especially Contrast or Brightness and Gamma for accumulation modes. Light render pixels are stored in three 32 bits floating point values, a precision you will never get from a standard bitmap graphic package. Therefore it is a good idea to keep post-processing enhancements to a minimum. Stretching a picture is definitely a Bad Thing, compositions should be planned well ahead. It's always a better idea to reduce the size of a picture rather than increasing it.
| fig. 7 : improving solid rendering | |
| 2 billions iterations, no post-processing | 1800*1800 render sized down to 600*600, thus obtaining a 3*3 anti-aliasing |
Final render
Once you are ready for the final render, increase the maximum iterations by at least one order of magnitude (200,000,000 is usually sufficient although very large projects will require more), change the number of updates to 1 and press F4. Once the image is rendered, you can make fine adjustments to mode specific parameters before saving your image.
Things to remember
- Choose the view angle carefully
- Don't limit yourself to a single rendering mode
- Default view size and gradients are not optimal in most cases, change them
- all adjustments that can be made in Chaoscope shouldn't be made later using a bitmap graphic software
- Never stretch a picture
- when you shrink a picture down, divide both width and height with the same integer number