Is this a bug?

[shvarz]

Here is something weird I noticed.  Just to re-cap, I am evolving Dom. Inv. to conditions with high friction and running food.  I started with Alga grexa as running food, but I was modifying it a bit to adjust for increasing friction.  Mostly I was increasing it's speed.  Now I am at friction 7.0 and I noticed something weird about the way Alga grexa is behaving: it often sits in one place, almost not running.  PY suggested that it is because veggies get body points when fed and that Grexa accumulates those body points and becomes so fat that it can't move.
So I added a gene that converts body into energy when body exceeds 5000, but that did not seem to help.  And about the same time I noticed that the whole energy flow in my sim started toget messed up: slight changes to amount of energy given to veggies led to huge variations in bot populations.  And another strange thing: Veggies would grow like crazy, yet I saw some of them simply go "puff!" and disappear as if from not geting enough energy.  Crazy stuff!!!

So I went to console and started poking around: What I see is that two veggies are almost identical, they have tons of energy (they are maxed out at 32000) and they have somewhere around 5000 body points (of course).  Yet one of them runs at pretty high speed, but the other one can barely move.  I am attaching the settings file and the new grexa.  Take a look and see if you can spot something weird or if you can explain what is going on.

[Shen]

YES! I thought I was going nuts! In my evo sims ive been noticing the same thing!

It shell, absurd amounts of it, like 5000. Your bots get more mass than there .up genes input so they cant move. I figured it was some wierd mutations spraying random values around the place but ruled that out. You sometimes get poison and venom as well.

At least I do, check yours and report back so I know im not going insane.

[Numsgil]

Definately check shell.  Shell really screws with speed, way more than body ever could.  And since the limit on shell has been eliminated, it's possible for bots to accumulate enough shell to not be able to move at all.

[shvarz]

Hmm, how would they get shell?  These are just veggies, there is no shell-making genes.  A bug? I'll check later, too drunk right now.

[PurpleYouko]

There is actually one small bug that I am aware of that relates to mutations.

Since the major changes in the mutations code recently, somehow a setting of zero in "Rate of mutation of mutations" doesn't get fixed properly.
In other words it mutates.
It takes a lot of iterations to move it away from zero due to the nature of the gaussian shift in rates. However it does eventually become one or two in some bots and then other rates begin to change.
I have seen a population of non-mutating bots produce major mutations occasionally. These mutations rarely survive though so they don't spread through a population like regular mutations.

It is possible that one of your sysvars has mutated in some of these veggies.

[shvarz]

No, my veggies are not mutated and I see this behavior almost immediately after I start the sim.

[Shen]

One thing might be waste. If your pushing your friction right up it takes huge amounts of nrg to move so the waste builds up quickly, then you get alzhiemers throwing large numbers into .mkshell etc. I only noticed this same thing when I put KE mode on so it could be that.

[shvarz]

Hmm, that's an idea.  I have KE mode ON.  So, can that be balanced by increasing the "Waste threshold"?  What does it do anyway?

[Numsgil]

Waste threshold increases the level of waste you need before bad things happen :P

[PurpleYouko]

Except that these are Alga we are talking about.
They should metabolize their waste to energy every cycle unless that has been changed recently or is broken.

[Numsgil]

But if they can't mebo it fast enough...

And pwaste levels slowly rise too.

[PurpleYouko]

Veggies were designed to never, ever build up either waste or pwaste. Unless something has been changed or broken with "feedveg2" or calls to it, this should not be possible.

It is possible that waste could very briefly cross the waste threshold in an alga that actively spends energy (like Grexa).

I have noticed that for some reason, .fixpos often gets set to non-zero in robots that are suffering from Altzheimer's. his means they can't move no matter how hard they try. This quite often happens in sims with older (pre-waste) robots like I-Flamma.

[Shen]

I've done a bit of testing and waste does indeed cause bots to make large amounts of shell. However Ive also seen bots accumulate large amounts of waste in very short periods, like 1000 in a few dozen cycles. So something is broken there me thinks.

Hmm, related bug. It seems collisions move fixed bots.

[PurpleYouko]

Hmm, related bug. It seems collisions move fixed bots.

Already noted this in a different thread and I have already fixed it in the latest release of 2.36.5 on the old FTP. Also allows my Inchworm bot to work properly again.

[shvarz]

Update:  Here is what I noticed: The "slow" bot can be turned into "fast" bot if it's speed is increased artificially.  I make a "fast" bot to crash into a slow bot and give it some momentum.  After that the "slow" bot runs fine on its own.

My guess is it has something to do with the way acceleration/decelaration/friction are calculated, becasue I started to see this problem when firction got pretty high.