In this post we will be discussing creating a realistic-looking lava effect, as seen in Brimstone and displayed below:
In order to create this we start with a basic fractal pattern: that of a Julia set whose complex parameter is c = 0 + i. This fractal looks as follows when displayed in red:
This gives us a great image of a "crack" to base all the rest of our image on. Now we simply create a canvas of whatever size we want, give it a black background, and draw this image thousands of times at random locations on the canvas and rotated at random angles. (See this post to find out more about drawing images at different angles on the canvas.) That's all there is to it! A surprisingly simple yet effective way to create a realistic-looking lava effect.
This same method can be applied to create other effects which rely heavily on tendrils or cracks; for example, simply making the Julia set green instead of red gave us a great moss-like texture for the tree in the Chicken Wings games: