Amazing Technicolor Sharks

When you start a new C3 world, your aquarium has a variety of colorful rainbow sharklings, but as time goes on they tend to become... not very rainbow. That does make sense, because offspring will have colors between those of their parents, so over the generations the colors will tend to go toward the middle of the color wheel. But maybe with a little tweaking, this could be fixed!

I do love that I can open C3/DS cos scripts and get the initial injection code, rather than having to backwards engineer it as in C1 and C2. Given how complicated many of the objects in C3/DS are, this sort of modification may well have been impossible without this small change in code accessibility! Here's the initial shark script - with a lot of unnecessary empty lines removed. Actually, this whole script seems to contain a lot of unnecessary stuff, such as a reps loop that runs once, or object variables that are set but never referenced. It feels very much like code that was never cleaned up after they got it functional.

The Original Script

For reference, the object variables that we care about are as follows:

• ov01: age
• ov02: fullness; the lower it is the hungrier the shark is
• ov05: adulthood flag; 2 indicates a mature adult.
• ov10: horizontal direction of movement
• ov11: vertical direction of movement
• ov19: lock A; makes sure a particular part of the code only runs once.
• ov20, ov21, ov22: genetic red, green, and blue values
• ov23, ov24, ov25: record of mate's red, green, and blue values.
• ov70: mated flag
• ov71: species identifier of the type of fish it hunts. If it can't find this type of fish, it'll randomly choose a different one.
• ov72: technically not unused, but it's only ever set and checked alongside ov05, and therefore seems to be redundant with it.
• ov80: marked for death flag; marks the shark to die after some time.
• ov81: death timer used in connection to the impending death flag.
• ov92: lock B; makes sure a different part of the code only runs once.
• ov99: supposed-to-be-dead flag; the shark was already supposed to be killed but for some reason couldn't be, so this flag indicates that it should be killed as soon as it's valid to do so.

Sharkling Inject Script

setv va00 0 reps rand 3 5   setv va60 rand 60 255   setv va61 rand 60 255   setv va62 rand 60 255   setv va40 3879   setv va41 2192   reps 1     addv va60 1     new: simp 2 16 4 "shark"       …153 0 4100     attr 199     clac -1     elas 20     aero 1     accg 0     perm 64     tint va60 va61 va62 128 128     mvto va40 va41     setv ov01 0     setv ov02 550     seta ov16 null     setv va50 rand 0 1     setv ov61 40     setv ov73 1     setv ov74 0     doif va50 = 0       setv ov10 -1       pose 0     elif va50 = 1       setv ov10 1       pose 8     endi     velo 0 0     setv va51 rand 1 4     doif va51 = 1       setv ov71 14     elif va51 = 2       setv ov71 15     elif va51 = 3       setv ov71 16     elif va51 = 4       setv ov71 19     endi     setv ov20 va60     setv ov21 va61     setv ov22 va62     tick 1   repe repe endm

set unused variable do this 3 to 5 times: { generate red value   generate green value   generate blue value   define starting position x   define starting position y   do this once:   { add 1 to red value for some reason     create new shark object       …     C/H carry, activatable, collisions and physics     when clicked, send no script     set bounciness     set aerodynamics     not affected by gravity     sets what walls it can go through     color according to the color values     move to starting position     set age to 0     set fullness to 550     save an unused reference     generate random cointoss value     save an unused value     save an unused value     save an unused value     if cointoss is 0     { set direction to left       left-facing sprite     } else if cointoss is 1     { set direction to right       right-facing sprite     }     no velocity     generate randomizer between 1 and 4     if randomizer is 1     { set prey type to angelfish     } else if randomizer is 2     { set prey type to clownfish     } else if randomizer is 3     { set prey type to hatchetfish     } else if randomizer is 4     { set prey type to neonfish     }     save genetic red value     save genetic green value     save genetic blue value     set timer to one tick   } }

Most of the shark's behavior is contained in the timer script, with several subroutines for different activities. Some of them aren't relevant to this project, so I'm not going to annotate them. Some of these are fairly self-explanatory: DETH kills the shark, OBST handles collisions with obstacles, GORT sets the velocity to the right and plays the rightward swimming animation, etc. Others require a little more explanation but don't merit an in-depth explanation: ROOM detects whether the shark is in salt water and adjusts its physics accordingly, and eventually kills the shark if out of water too long. INIM handles the shark's velocity. MARK literally just sets the impending death flag. RNDM randomly changes the direction the shark is moving in. FLOK allows the sharks to swim together in a school.

Sharkling Timer Script
scrp 2 16 4 9   gsub room   doif ov99 = 5     gsub deth   endi   doif ov01 >= 3000     gsub deth   endi   addv ov01 1   doif ov01 > 1200 and ov19 = 0     setv ov05 2     setv ov72 0     setv ov19 1   endi   subv ov02 1   doif ov70 = 1     gsub repr     setv ov70 0     gsub mark   endi   doif ov80 = 1     addv ov81 1     doif ov81 = 15       gsub deth     endi   endi   doif ov05 = 2 and ov72 = 0       …and ov80 <> 1     gsub mate   endi   doif ov02 >= 500     doif ov92 = 0       gsub inim       gsub obst       gsub swim       gsub move       setv ov92 1     elif ov92 = 1       setv va00 rand 1 5       doif va00 <= 2         gsub flok       else         gsub rndm       endi       gsub obst       gsub swim       gsub move     endi   elif ov02 < 500 and ov02 > 0     gsub hunt     gsub obst     gsub swim     gsub move     gsub eat_   elif ov02 <= 0     gsub deth   endi	SHARKLING TIMER SCRIPT   run ROOM subroutine   if the shark is supposed to be dead   { run DETH subroutine   }   if age >= 3000   { run DETH subroutine   }   add 1 to age   if age > 1200 and lock A isn't set   { set adulthood flag     set redundant adulthood flag     set lock A   }   decrease fullness by 1   if mated   { run REPR subroutine     set not mated     run MARK subroutine   }   if marked for death   { add 1 to death timer     if death timer = 15     { run DETH subroutine     }   }   if adult and redundantly adult       …and not marked for death   { run MATE subroutine   }   if fullness >= 500   { if lock B not set     { run INIM subroutine       run OBST subroutine       run SWIM subroutine       run MOVE subroutine       set lock B     } else if lock B is set     { generate randomizer between 1 and 5       if randomizer <= 2       { run FLOK subroutine       } else       { run RNDM subroutine       }       run OBST subroutine       run SWIM subroutine       run MOVE subroutine     }   } else if fullness between 500 and 0   { run HUNT subroutine     run OBST subroutine     run SWIM subroutine     run MOVE subroutine     run EAT subroutine   } else if fullness <= 0     run DETH subroutine   }
subr mate     rnge 100     inst     esee 2 16 4       doif targ <> null         doif ov05 = 2           setv va70 1           setv va20 ov20           setv va21 ov21           setv va22 ov22         endi       endi     next     slow     doif va70 = 1       setv ov70 1       setv ov23 va20       setv ov24 va21       setv ov25 va22     endi   retn	MATE SUBROUTINE     set the range for detection     run this section instantly     for each shark in range     { if target isn't null       { if target is adult         { locally set mated flag           locally save target's red value           locally save target's green value           locally save target's blue value         }       }     }     end instantaneous section     if local mated flag     { set real mated flag       save mate's red value       save mate's green value       save mate's blue value     }    end subroutine
subr repr     setv ov08 0     setv va34 0     rnge 1000     esee 2 16 4       addv va34 1     next     doif va34 <= 5       setv ov08 rand 1 20       doif ov08 = 5         setv ov08 rand 1 3       else         setv ov08 rand 1 2       endi     else       setv ov08 0     endi     doif ov08 <> 0       reps ov08         setv va00 rand 1 5         doif va00 = 5           setv va20 rand 06 255           addv va20 ov20           divv va20 2           doif va20 < 50             addv va20 20           endi         else           setv va20 ov20         endi         setv va00 rand 1 5         doif va00 = 5           setv va21 rand 60 255           addv va21 ov21           divv va21 2           doif va20 < 50             addv va20 20           endi         else           setv va21 ov21         endi         setv va00 rand 1 5         doif va00 = 5           setv va22 rand 60 255           addv va22 ov22           divv va22 2           doif va20 < 50             addv va20 20           endi         else           setv va22 ov22         endi         addv va26 ov20         addv va26 ov23         addv va26 va20         addv va27 ov21         addv va27 ov24         addv va27 va21         addv va28 ov22         addv va28 ov25         addv va28 va22         divv va26 3         divv va27 3         divv va28 3         setv va80 posl         setv va81 post         new: simp 2 16 4 "shark"             …153 0 4100         attr 199         clac -1         elas 20         aero 1         accg 0         perm 64         tint va26 va27 va28 128 128         mvto va80 va81         setv ov01 0         setv ov02 550         seta ov16 null         setv va50 rand 0 1         setv ov61 40         setv va51 rand 1 4         doif va51 = 1           setv ov71 14         elif va51 = 2           setv ov71 15         elif va51 = 3           setv ov71 16         elif va51 = 4           setv ov71 19         endi         setv ov73 1         setv ov74 0         doif va50 = 0           setv ov10 -1           pose 0         elif va50 = 1           setv ov10 1           pose 8         endi         setv ov20 va26         setv ov21 va27         setv ov22 va28         velo 0 0         tick 1       repe       targ ownr       setv ov70 0       gsub mark     endi   retn	REPR SUBROUTINE     set number of offspring to 0     set shark counter to 0     set long range     for each detected shark     { add 1 to shark counter     }     if shark counter <= 5     { set number of offspring between 1 and 20       if number of offspring is 5       { set number of offspring between 1 and 3       } else       { set number of offspring between 1 and 2       }     } else     { set number of offspring to 0     }     if number of offspring is not 0     { for that number of times       { set mutation flag between 1 and 5         if mutation flag = 5         { set temp red between 6 and 255           add parent's red value           divide by 2 (for average)           if temp red < 50           { add 20 to temp red           }         } else         { set temp red to parent red         }         set mutation flag between 1 and 5         if mutation flag = 5         { set temp green between 60 and 255           add parent's green value           divide by 2 (for average)           if temp red < 50           { add 20 to temp red           }         } else         { set temp green to parent green         }         set mutation flag between 1 and 5         if mutation flag = 5         { set temp blue between 60 and 255           add parent's blue value           divide by 2 (for average)           if temp red < 50           { add 20 to temp red           }         } else         { set temp blue to parent blue         }         add parent red to offspring red         add mate red to offspring red         add temp red to offspring red         add parent green to offspring green         add mate green to offspring green         add temp green to offspring green         add parent blue to offspring blue         add mate blue to offspring blue         add temp blue to offspring blue         divide offspring red by 3 (for average)         divide offspring green by 3 (for average)         divide offspring blue by 3 (for average)         save left position         save top position         create new shark object             …          C/H carry, activatable, collisions, physics         when clicked send no script         set bounciness         set aerodynamics         not affected by gravity         sets what walls it can go through         color according to offspring colors         move to saved position         set age to 0         set fullness to 550         save an unused reference         generate random cointoss value         save an unused value         generate randomizer between 1 and 4         if randomizer is 1         { set prey type to angelfish         } else if randomizer is 2         { set prey type to clownfish         } else if randomizer is 3         { set prey type to hatchetfish         } else if randomizer is 4         { set prey type to neonfish         }         save an unused value         save an unused value         if cointoss is 0         { set direction to left           left-facing sprite         } else if cointoss is 1         { set direction to right           right-facing sprite         }         save genetic red value         save genetic green value         save genetic blue value         no velocity         set timer to one tick       }       target the parent again       set not mated       run MARK subroutine     }   end subroutine

There are numerous errors in the reproduction script. A typo causes the temporary red value to be generated between 6 and 255 rather than 60 and 255. When the green and blue values mutate, they erroneously verify that the red value is greater than 50 rather than checking themselves. Not to mention, even when they do mutate, the mutated color is averaged with the parent's value, and then averaged again with the parent and the mate, severely muting it.

Simulation and Algorithm Selection

Because it would take a while to breed generations of sharks for testing, I figured it would be wise to write a program that simulated the shark genetics quickly. This script cuts the shark behavior down to the essentials - instead of tracking hunger and hunting, I just occasionally kill a shark at random to simulate starvation; instead of tracking whether sharks are near enough to each other to mate, I just use another random number to determine if a mate is successfully found, and then select a second shark randomly from the list. Aging, reaching adulthood, and dying of old age or after mating are simulated.

The program was initially text-only, but seeing a wall of numbers wasn't nearly as helpful as seeing actual colors, so I added some limited graphical capabilities: a grid of boxes, each representing the color of a specific shark (with its ID number written on it for clarity). Each row, starting at the top, represents a point in time - a new row is printed whenever a shark dies or is born.

The Original Algorithm

To get a good range of data, I ran each algorithm a few times, and in the images below, I've put the different outputs side by side, divided by a thin black line.

As expected, implementing the existing algorithm results in a population that doesn't take long to converge on a single dull color, such as the ones I've seen in game.

The Fixed Original Algorithm

The original algorithm had several errors, as I've pointed out. I decided to see what would happen if I left the overall structure intact, but fixed the obvious mistakes (correcting 06 to 60, making sure the mutation code actually checks the correct color, etc).

These corrections do result in brighter colors! However, they still converge on a single color relatively quickly, making for a boring population.

The "Wild Mutation" Algorithm

My first attempt at improving the algorithm was to do away with the complexities of averaging the mutations into the parent colors, allowing them to be more dramatic. I changed the color calculation to average the parent colors first, and then randomly determining whether to mutate afterwards. If the color did mutate, it did so to a random value between 60 and 255, completely unrelated to the parent colors, end of story.

As expected, my wild mutations resulted in a population that changed considerably over time, showing off a variety of usually-bright colors. Unfortunately, the individuals within the population generally were fairly similar to each other, with the occasional mutated oddball providing genetic drift rather than inducing variety in the population.

The Weighted Mutation Algorithm

I made one more edit to my algorithm to specifically combat samey-ness in the population. When determining whether to mutate the offspring, I cheated a little bit: for each color channel, if the parents' color values were particularly close to each other, I forced a mutation. This way, parents with wildly different colors will produce logically averaged offspring, but if they're too similar, the gene pool gets a new injection of color.

Now that is the desired result! The colors aren't completely random; a red shark and a blue shark will produce purple offspring, giving a sense of continuity to the population, but at the same time, variety is enforced enough to truly earn the name rainbow sharkling!

If you'd like to play with the python script I used to simulate the populations, you can download it here. You'll need python 3.8 and the tkinter library installed to use it, and you can switch between the algorithms I tested by changing self.weighteddmutationCalcColor() on line 209 to self.originalCalcColor(), self.fixedCalcColor(), or self.wildmutationCalcColor().

The Alteration

With a new algorithm selected, I modified the sharkling script and injected it into the world. We shall see how it pans out! I only changed the REPR subroutine, basically cutting out the entire color calculation chunk and replacing it with all new code.

Modified Sharkling REPR Script

… doif ov08 <> 0   reps ov08     setv va00 rand 1 4     setv va26 ov20     addv va26 ov23     divv va26 2     setv va20 ov20     subv va20 va26     absv va20     doif va20 < 15       setv va00 4     endi     doif va00 = 4       setv va26 rand 60 255     endi     setv va00 rand 1 4     setv va27 ov21     addv va27 ov24     divv va27 2     setv va21 ov21     subv va21 va27     absv va21     doif va21 < 15       setv va00 4     endi     doif va00 = 4       setv va27 rand 60 255     endi     setv va00 rand 1 4     setv va28 ov22     addv va28 ov25     divv va28 2     setv va22 ov21     subv va22 va28     absv va22     doif va22 < 15       setv va00 4     endi     doif va00 = 4       setv va28 rand 60 255     endi     setv va80 posl     setv va81 post     new: simp 2 16 4 "shark" 153 0 4100     attr 199     clac -1     elas 20     aero 1     accg 0     perm 64     tint va26 va27 va28 128 128     mvto va80 va81     …

… if number of offspring is not 0 { for that number of times   { set mutation flag between 1 and 4     set offspring red to parent red     add mate red to offspring red     divide by 2 (for average)     set diff red to parent red     subtract offspring red from diff red     take absolute value of diff red     if diff red < 15     { set mutation flag to 4     }     if mutation flag = 4     { set offspring red between 60 and 255     }     set mutation flag between 1 and 4     set offspring green to parent green     add mate green to offspring green     divide by 2 (for average)     set diff green to parent green     subtract offspring green from diff green     take absolute value of diff green     if diff green < 15     { set mutation flag to 4     }     if mutation flag = 4     { set offspring green between 60 and 255     }     set mutation flag between 1 and 4     set offspring blue to parent blue     add mate blue to offspring blue     divide by 2 (for average)     set diff blue to parent blue     subtract offspring blue from diff blue     take absolute value of diff blue     if diff blue < 15     { set mutation flag to 4     }     if mutation flag = 4     { set offspring blue between 60 and 255     }     save left position     save top position     create new shark object     C/H carry, activatable, collisions, physics     when clicked send no script     set bounciness     set aerodynamics     not affected by gravity     set what walls it can go through     color according to offspring colors     move to saved position     …

All that remains now is to observe how this modified code pans out, but that will take time, so I'll do that over the next few sessions in Eden. If I like the results, I'll add it to the downloads page. Otherwise, we've got more work to do.