|Re: [eigen] Rigid Transformations in eigen: discussion thread|
[ Thread Index |
| More lists.tuxfamily.org/eigen Archives
- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] Rigid Transformations in eigen: discussion thread
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Fri, 18 Sep 2009 14:07:04 +0200
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=uAnDMD/FrZWQnjoE9Lz5qooy7XNk9pYy/UrWJxo0KUY=; b=enOmRdKPcRe0N5OSAX2WwZk3wpsdI5CBcghsOQJxtouYWJQhU8un3pokjDRV4z/5RW fZBE223r72FKH5rFufLBp5is3SKoft3qwx+H4/3vKwxUzCzJdwuf1780xkwE9ti3yfwI RrpVOWFnpdqTgFSM3jryOr53JNlTBpT8RJ8oU=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Hvz8fiSFBnhTJxSFFAtr879Iao7xnDXpLmOAuHOONo1JJLOWDDsg99YnlJGQKhpedg 7eIpsQGwtrooMeblkIs+cypvGzqKjmRUHgrn+Ls22uxJqK33jRwNG7Jzh+A7iO5lMBXh VvOZRcy7DfVpPGMbuW+JJgZD3YUMaVb0Vt0mA=
On Fri, Sep 18, 2009 at 2:01 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
> 2009/9/18 Gael Guennebaud <gael.guennebaud@xxxxxxxxx>:
>> maybe it is still worth keeping Scalar so that one can easily declare
>> a DualQuaternion:
>> DualQuaternion<float> dq;
>> For an example of this technique have a look at my auto-diff module in
>> Finally, do you think Quaternion should be implemented this way as
>> well ? I mean for DualQuaternion these two operators are really useful
>> (unlike for Quaternion where slerp is really what you should use), and
>> since dualquat are larger high efficiency require ET (again unlike
> I think it's worth doing the same for Quaternion for consistency.
I agree on the consistency reason.
> DualQuaternion has an operator+, then Quaternion should too. Rohit
> mentioned that nlerp is also wanted for Quaternion. Then there is the
> question of whether it should return by value or using your trick,
> well i think that your trick brings more benefits (e.g. mapping
> expressions) so once we have the DualQuaternion impl it's worth
> porting to Quaternion... also it's a more consistent API: if
> DualQuaternion can Map any xpr, so should Quaternion.
Note that mapping the coefficients of a Quaternion or DualQuaternion
seems to be quite dangerous because this assume a convention for the
storage order of the coeffs and there is no such standard.