[sldev] Client FPS & LLQuaternions

[Kent Quirk (Q Linden)]

...and there you have it.

 From llquaternion.cpp:

// Saves space by using the fact that our quaternions are normalized
void LLQuaternion::unpackFromVector3( const LLVector3& vec )

Sorry for the confusion. I've updated that line of the wiki.

	Q

On Feb 18, 2008, at 1:56 AM, Tofu Linden wrote:

> This is simply a guess, but if we're enforcing unit quaternions then a
> 4th coefficient can be inferred from the other three - so
> sending just three over the wire is an optimization.
>
> Thomas Grimshaw wrote:
>> I've undone the zerocoding, and the official client only sends  
>> three F32 values per llQuaternion in
>> the AgentUpdate packet. I've also written my own dummy client, and  
>> confirmed that 16 byte
>> values are not accepted by the sim in this particular message.
>> Cheers
>> Tom
>> ----- Original Message ----- From: "Kent Quirk (Q Linden)" <q at lindenlab.com 
>> >
>> To: "Thomas Grimshaw" <tom at streamsense.net>
>> Cc: "Second Life Developer Mailing List" <sldev at lists.secondlife.com>
>> Sent: Monday, February 18, 2008 5:18 AM
>> Subject: Re: [sldev] Client FPS & LLQuaternions
>>> A quaternion can be used as a way of expressing a 3D rotation.  
>>> Second  Life uses unit quaternions, which would normally be  
>>> expressed as four  real numbers.
>>>
>>> As far as I can tell, the Message_Layout page is correct -- it  
>>> should  be 16 bytes, or four F32 values.
>>>
>>> What makes you say it's only 12? The AgentUpdate message is  
>>> zerocoded  --  are you perhaps getting misled because zero values  
>>> are compressed?
>>>
>>> Q
>>>
>>>
>>>
>>> On Feb 17, 2008, at 8:19 PM, Thomas Grimshaw wrote:
>>>
>>>> Secondly, LLQuaternions
>>>>
>>>> Could somebody please update this wiki page:
>>>>
>>>> http://wiki.secondlife.com/wiki/Message_Layout
>>>>
>>>> to describe the correct LLQuaternion specification. That page   
>>>> describes it as 16 bytes, however it seems both the official  
>>>> client  and LibSL sends 12 bytes in the AgentUpdate packet. What  
>>>> gives?
>>>
>>>
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