Re: [simspark-devel] Problem with the vision perceptor (I think!)

[Jan M. <mu...@un...>]

Joschka Boedecker wrote:
> Hi,
> 
> On Mon, 2007-06-18 at 22:06 +1000, Oliver Obst wrote:
> 
>> On 18/06/2007, at 8:42 PM, Joschka Boedecker wrote:
>>
>>>>>  To be more consistent, we may avoid using left and right for the  
>>>>> flags
>>>>> altogether. For example, we may call: our flags and opponent  
>>>>> flags! And we
>>>>> may use left and right instead of 1 and 2 which are used  
>>>>> currently. So, we
>>>>> will have "our left flag(FLO), our right flag (FRO),..."!! (This  
>>>>> is an
>>>>> example only).
>>>>>
>>>> Good idea! This is what exactly my mean ;-)
>>>> This is useful while teams design strategy and formation, I think.
>>>>
>>>> Joschka, will we use the new flag names?
>>> I think it's a good idea. But we should choose different names from
>>> "our" and "opponent" (both start with 'O' ;-) ). How about "my  
>>> team" (M)
>>> and "opponent team" (0). So it would look like:
>> I'm not sure if I missed something, but as far as I understood the  
>> discussion so far, I don't agree it's a good idea.
>>
>> The flag names (with "left" and "right" for flags on the left/right  
>> side of the field) should be equally perceived by agents of both teams.
>> This is consistent with that real robots on the field see the same  
>> flag on the field in equal colors.
> 
> True.

>> If you label the flags with "my" / "opponent", this is a _semantic_  
>> annotation of the flag that can't be found on the soccer field. The  
>> vision perceptor should only deliver the syntactic label of the flag,  
>> and the intelligence of deciding which side the flags belong to  
>> should be in the agent, not in the simulator.
> 
> Wasn't there something like flipping the labels in the old simulator?
> Maybe I'm completely wrong though, I didn't check...

I checked the visionperceptor of version 0.4. There all 
(x/y)-coordinates were multiplied with -1 for the right team for the 
static and dynamic axis percept. I think this goes back to the time 
before we used the dynamic axis. In those days ;-) it was easier to say 
the x-axis points towards the opponent goal.

What I didn't get from the previous discussion is whether only the 
flag/goal labels should be flipped, or all positions should be flipped.

>> So IMHO, flipping the labels should be removed from the perceptor,  
>> and using "left" for the left flags of teams of either side isn't any  
>> better than the original labels.

In this case we could perhaps replace left and right with yellow and 
blue.  This avoids confusion if you move the camera round and the yellow 
goal is on the right, suddenly.  ;) But then we should apply this to the 
gamestateperceptor as well.

> OK, so we leave the old labels and remove the flipping?

This would be like 2D. IIRC the vision in the 2D simulator was exactly 
as Oliver proposed.

I tend to agree with Oliver. It's easy for a team to implement a flip 
based on their side, but it's (unnecessary) overhead for the simulator.

Bye,
  Jan