Starfield with Nebula
by Rychveldir
This tutorial takes the well known and beginner-friendly spherical plants from the good old 2D into the third dimension, and the results that can be achieved with relatively little are absolutely stunning! Here's a little example...
We start by emulating the basic structure of two iterators with just a spherical transform, but we also need an affine for each one (the triangle/two arrows known from Apophysis, Chaotica, Fratorium or Fractron9000). So what used to be a single iterator now consists of a pair of iterators, one affine and one spherical. Each affine is only linked to its spherical (it basically acts as pre-affine), and each spherical is linked to both of the affines. We also hide the affines (by clicking on the eye). This isn't necessary, but it more clearly emulates the 2D version. Feel free to keep them visible or add additional links between the iterators or even with themselves (right click) to try out how it affects the image!
The loop should look as follows:
First, make sure you set the Warmup (right side next to your preview image) to 70 (or something around that value, test what works best).
Just like with 2D spherical plants, the spherical transform itself doesn't need to be changed, but I'll provide you with some starting values for your affines just to give you an idea of how this works out. Select your first affine and change the values for translate and rotate:
Now select the second affine and enter the following values:
Your preview should now look roughly like this:
The next step is to add some stars. This can be done by linking Gaussian blur iterators to the spherical iterators. Click one of your sphericals to select it, then click Gaussian Blur on the left hand side. Your loop should now look like this (if you arrange it like this):
Your entire nebula just turned into little fuzzy spheres. Set the Base Weight to 0.15 and the Raidus to 0.0005, this will make the fuzzy spheres small enough to pass for stars, and the lower weight will make your original nebula visible along with the stars. This also has the nice side effect of concentrating most of the stars where the nebula is the densest. If you don't want them to align, you can instead make a completely separate loop for your stars and keep the Base Weight at 1 (or lower it), this will allow you to change your star field without touching the nebula. If you find your stars to be too bright and visible while the nebula is very faint, just click one of your iterators in the nebula loop and increase its Starting Weight to make the nebula brighter and the stars fainter. A value of 100 has worked well for me, but try what works best for you!
If you followed the above steps and changed your loop to the values shown in the image, your preview should now look like this:
This is already pretty nice! Now let's add some color. Just to show you how I did it for this example, here are my values:
- From ChaosHelper, I took Gradient 1 from tatasz_pack_03.gradient
- Take Affine 1 and set the Color Index to 0.0 and the Color Speed to 0.33
- Take Affine 2 and set the Color Index to 1.0 and the Color Speed to 0.33
Great, now for the final steps. You can rotate, zoom, move, whatever you want, just turn your nebula until you like what's in your image and then tweak brightness, gamma, and vibrancy until you like the result. For this example, after moving the camera in a spot I liked, I picked the following values: Brightness: 30 Gamma: 0.5 Vibrancy: 0.6
Here's the final result:
Tweak your nebula and/or starfield by shifting values in your affines and see the effect in real time. Add a second loop for more nebula or stars. Link iterators or shift weights around, there are no limits! :)