Fish Sizes

PaulS · 04-01-2004, 02:07 PM

I have kept marine fishes and I must say that the Marine Aquarium is a remarkable simulation. Amazing!

One thing that I would quite like, and (speaking as a software developer) I imagine would not be too difficult (?!) would be the ability to vary the relative fish sizes, say +/- 30% of the default size (if you do this in, say, 10% increments you would presumably limit the number of texture maps required). I had a picasso trigger that got quite large compared with others.

Failing that, let's have inverts, inverts, inverts!

Well done all!

Jim Sachs · 04-01-2004, 02:58 PM

Welcome, Paul.

The fish could be made smaller, but bigger would cause major collision-detection problems.

Invertebrates will be included in "Creature Packs" which will be sold separately. The prices haven't been set, but I'm thinking about $10 for 10 critters. I have to finish the Freshwater program before I can start working on these, so it may be a while.

Sergiales · 04-02-2004, 02:03 AM

...but bigger would cause major collision-detection problems.

Please Jim, could you explain us with few words how the collision-detection algorithm that you've implemented works?.
Thanks.

Jim Sachs · 04-02-2004, 10:26 AM

Not very well.

drfish · 04-02-2004, 10:45 AM

Jim Sachs · 04-02-2004, 11:19 AM

With 7 fish in the tank, there are occasional fish-to-fish and fish-to-coral pass-throughs. If a fish object is closing in on another object, it will attempt to turn around. If there is another object behind it, it's in trouble and will attempt to go higher or lower to avoid the object. If it's already near the top or the floor, then it will just hold its position and hope the other fish will move. Smaller fish will generally turn away from bigger fish.

It's all incredibly complicated, and will be re-worked when I put in the 3D background. The main problem is collision PREDICTION. A fish migh see a clear path ahead, and put on a burst of speed, but a moment later another fish might suddenly block its path. Big fish can't exactly stop on a dime, so I have to find some graceful way of avoiding a pass-through. Every possible turning direction has to be checked to see if another object is either in the way, or soon would be. Even stopping might be a problem if there's another fish behind it, and gaining (I just HATE tailgaters!).

Submariner · 04-04-2004, 06:59 PM

What about Aqua real you can have up to 15 fish
in the tank. They use collision detection. Is it
because the fish meander more?/

Jim Sachs · 04-04-2004, 08:50 PM

Haven't really looked at it much. They don't have collisions? Even if they don't -- that was them, this is me. Things like that are usually closely-guarded secrets.

Sergiales · 04-05-2004, 01:44 AM

Is fish size involved into the collision-detection algorithm?.

If the answer is YES, then there shouldn't be major collision-detection problems.

Jim Sachs · 04-05-2004, 08:56 AM

Fish size is involved in the fact that smaller fish will generally turn away from larger fish.

04-01-2004, 02:07 PM	#1
PaulS Registered Join Date: Apr 2004 Location: Caterham, England Posts: 1	Fish Sizes I have kept marine fishes and I must say that the Marine Aquarium is a remarkable simulation. Amazing! One thing that I would quite like, and (speaking as a software developer) I imagine would not be too difficult (?!) would be the ability to vary the relative fish sizes, say +/- 30% of the default size (if you do this in, say, 10% increments you would presumably limit the number of texture maps required). I had a picasso trigger that got quite large compared with others. Failing that, let's have inverts, inverts, inverts! Well done all! Eschew Obfuscation...Anon

04-01-2004, 02:58 PM	#2
Jim Sachs Developer Join Date: Dec 2000 Location: Southern Oregon Posts: 9,791	Welcome, Paul. The fish could be made smaller, but bigger would cause major collision-detection problems. Invertebrates will be included in "Creature Packs" which will be sold separately. The prices haven't been set, but I'm thinking about $10 for 10 critters. I have to finish the Freshwater program before I can start working on these, so it may be a while. Jim Sachs Creator of SereneScreen Aquarium

04-02-2004, 02:03 AM	#3
Sergiales Software Engineer Join Date: Feb 2003 Location: Spain Posts: 266	...but bigger would cause major collision-detection problems. Please Jim, could you explain us with few words how the collision-detection algorithm that you've implemented works?. Thanks. Sincerely, Sergio.

04-02-2004, 10:26 AM	#4
Jim Sachs Developer Join Date: Dec 2000 Location: Southern Oregon Posts: 9,791	Not very well. Jim Sachs Creator of SereneScreen Aquarium

04-02-2004, 10:45 AM	#5
drfish the Doc Join Date: Feb 2002 Location: Zeeland, MI Posts: 5,357	I don't watch commercials.

04-02-2004, 11:19 AM	#6
Jim Sachs Developer Join Date: Dec 2000 Location: Southern Oregon Posts: 9,791	With 7 fish in the tank, there are occasional fish-to-fish and fish-to-coral pass-throughs. If a fish object is closing in on another object, it will attempt to turn around. If there is another object behind it, it's in trouble and will attempt to go higher or lower to avoid the object. If it's already near the top or the floor, then it will just hold its position and hope the other fish will move. Smaller fish will generally turn away from bigger fish. It's all incredibly complicated, and will be re-worked when I put in the 3D background. The main problem is collision PREDICTION. A fish migh see a clear path ahead, and put on a burst of speed, but a moment later another fish might suddenly block its path. Big fish can't exactly stop on a dime, so I have to find some graceful way of avoiding a pass-through. Every possible turning direction has to be checked to see if another object is either in the way, or soon would be. Even stopping might be a problem if there's another fish behind it, and gaining (I just HATE tailgaters!). Jim Sachs Creator of SereneScreen Aquarium

04-04-2004, 06:59 PM	#7
Submariner Registered Join Date: Sep 2003 Location: Connecticut Posts: 905	What about Aqua real you can have up to 15 fish in the tank. They use collision detection. Is it because the fish meander more?/ http://3dfishworld.x10host.com

04-04-2004, 08:50 PM	#8
Jim Sachs Developer Join Date: Dec 2000 Location: Southern Oregon Posts: 9,791	Haven't really looked at it much. They don't have collisions? Even if they don't -- that was them, this is me. Things like that are usually closely-guarded secrets. Jim Sachs Creator of SereneScreen Aquarium

04-05-2004, 01:44 AM	#9
Sergiales Software Engineer Join Date: Feb 2003 Location: Spain Posts: 266	The question... Is fish size involved into the collision-detection algorithm?. If the answer is YES, then there shouldn't be major collision-detection problems. Sincerely, Sergio.

04-05-2004, 08:56 AM	#10
Jim Sachs Developer Join Date: Dec 2000 Location: Southern Oregon Posts: 9,791	Fish size is involved in the fact that smaller fish will generally turn away from larger fish. Jim Sachs Creator of SereneScreen Aquarium