Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions |

[ Thread Index | Date Index | More lists.tuxfamily.org/eigen Archives ]

*To*: eigen@xxxxxxxxxxxxxxxxxxx*Subject*: Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions*From*: Rohit Garg <rpg.314@xxxxxxxxx>*Date*: Sat, 12 Sep 2009 20:20:31 +0530*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=Ihlz7B5B6mb6TfhvL4FYuFnNXZPPnFi8Fodq4K6C+qg=; b=cVB+tjopgKBQPpfE3jBNUtaNHspTT8LTOvKNrybSQ65LhcrMriSDiNRjStuXf1N+DY DDijWgIto/QXYu3s5KBdSATZNbKdnrk8Sdecrbn+aefwf6+myOEsR+262BOcdvRMFs22 bXkQU1aXdQvp0FeuhWcjt7XadfqvYKDc+M8OY=*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=RYiYhQSUyRkjyR2LQJ8PHzMn2oPaTCMGp3d5Bjj6tVZ75NzZ0gleujoWarGZ3IaZ1p GrOIeI0E+XCEUbm02HPAKhrmIGB4jWFn9jWmecnMXCZbY8+VZqvrWAdW5XRYunLaADaw ebuiX3tWkl8xQE5b1oI9ARzI3Ogg+coRLbbcE=

On Sat, Sep 12, 2009 at 7:59 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote: > careful, your patch affects test/CMakeLists.txt in unwanted ways ! Oh I commented out the unit tests I wasn't gonna build. That's all. Ignore that part. > that aside: for now, we only dealt with unit quaternions. These are > the quaternions that correspond to 3D rotations. > > That's the main reason why we didn't implement q1+q2 and q*scalar. I tried implementing dual quats over eigen quats, and that's where I ran into this. > Now your patch does work, but it's not always efficient, because the > operators return by value and so when you do s1*q1+s2*q2 you traverse > the arrays 3 times instead of once. Again this doesn't matter with > floats and SSE, but it does with double and/or without SSE. Oh yeah, that's true :( > > Making this efficient would require again doing expression templates. > If we wanted to take that route, I guess we could as well make > Quaternion inherit MatrixBase instead of reimplementing everything. Ok, so rotationbase is different from matrixbase. Thanks for clearing that up. > even Matrix. I don't remember the chain of thinking that led to the > current design, it's Gael who took care of that. It has the advantage > of being simple and covering _unit_ quaternions appropriately. > > But are you sure that what you're trying to do with s1*q1+s2*q2 isn't > just the same as slerp() ? because it looks seriously reminiscent of > it! The form is like that, but it is not slerp. That would have made my job so much easier :| -- Rohit Garg http://rpg-314.blogspot.com/ Senior Undergraduate Department of Physics Indian Institute of Technology Bombay

**Follow-Ups**:**Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions***From:*Benoit Jacob

**References**:**[eigen] Rigid transformations in eigen: use of dual quaternions***From:*Rohit Garg

**[eigen] Re: Rigid transformations in eigen: use of dual quaternions***From:*Rohit Garg

**Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions***From:*Benoit Jacob

**Messages sorted by:**[ date | thread ]- Prev by Date:
**Re: [eigen] Rigid transformations in eigen: use of dual quaternions** - Next by Date:
**Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions** - Previous by thread:
**Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions** - Next by thread:
**Re: [eigen] Re: Rigid transformations in eigen: use of dual quaternions**

Mail converted by MHonArc 2.6.19+ | http://listengine.tuxfamily.org/ |