The approach used in the Knight Rider sketch allows for lots of variations. Tweaking the brightness function will give various nice effects.
uint8_t brightness(const int8_t led, const int8_t pos) {
switch (min(abs(led-pos),abs(19-led-pos))) {
case 0: return 32;
case 1: return 16;
case 2: return 6;
case 3: return 2;
default: return 1;
}
}
Replacing the brightness function as indicated above will give 2 cursors move back and forth.
Another nice effect is achieved with the following brightness function.
uint8_t brightness(const int8_t led, const int8_t pos) {
int8_t tmp = pos - abs(2*led-19)+2;
return (tmp>0? tmp+tmp>>1: 0);
}
It delivers some “glowing” blink effect.
What is the coolest effect you can create? Once you finish playing with these effects go on to the persistence of vision experiments.
Blinkenlight 
Is there a program to create the warp core effect in Star Trek The Next Generation? I think it would be similar to the double chaser.
No, I did not create such a program. But of course you can write one on your own. This would be a beginner level project. So feel free to try.