On Tue, Mar 12, 2002 at 10:49:28PM -0500, Fred Klingener wrote: > The Matrix?? classes have transform()s for corresponding Tuples, Points and > Vectors. If you need more (or different?) GMatrix and GVector have a lot of > useful stuff. > ah, how could i miss the transform() method ?
> You get the Quat4d.mul(Quat4d), and you can compose the vector spherical > transformation from that. I suppose that your talking about Q V Q*? > yup, its really nice when rotating a point around a quaternion. i implemented it in the code applied. > This is one of those little nasty surprises that seem to be rites of passage > working with vecmath. It's kind of like hazing. Welcome to the club. > hehe, thanks, its been a rough ride :) > >With quaternion vector multiplication implemented the need of removing > >normalizing when creating a object will parially remove this problem, > >since this often happen when multiplying two quaternions when one is > >actually a vector. Other very useful methods like rotate a point with > >a quaternion is also missing. > > It might be nice to have the spherical quaternion transformation, but broad > interest in that corner of modeling is some time off. > i find that strange, quaternions are so much more usable than matrixes when dealing with rotations. (other areas too, but thats another story :) > >In that respect i have written some classes that extends the existing > >javax.vecmath.* classes. The classes are included as attachment. > > I'll take a look at it as soon as I can get my de-tarrer working. i though winzip read tar packages ? >I have a dual number package simmering away that I'll publish some day. >If there's any interest in it at all, I hurry. >It's built on top of vecmath e.g. it uses a Vector3d and a double for >quaternion, so if vecmath ever gets accelerated, this math should go along. >It includes dual numbers, dual vectors, and dual quaternions - all magical > that sounds neat, i would really like to have a look at it. for now i have all the methods i need to implement a rbd library. is going good too :) >> would reconsider your decision of normalizing quaternions. > > I think that it will come eventually, but there'll be not much interest in it > in the near future. My own take on the way it might happen is this: The drive > for more plausible-looking games will result in more and more content being > generated by physics simulations. I suspect that here is where the quaternion > camel pokes his nose under the tent. Spherical quaternion transformations have > been embraced wholeheartedly by the gamers to do rotational interpolations, and > some day some of the dual quaternion-based inverse kinematics solvers might be > similarly embraced. At some point, the thrashing between the state equations > of the physics model and the matrix transformations of the display model will > become intolerable, and both spherical and spatial quaternion transformations > will start to take some of the load. > > Some day, those transformations might move onto hardware. All of the registers > in nVidia GeForce VIII might be dual quaternion registers and the spatial > transformation would be done in two clock ticks once the pipeline got loaded. > > When that happens, the software and the object models have to change, and Java > 3D 3.4beta3 will be ready. > hehe, i wont hold my breath, but quaternion transformation in hardware would really be a good thing. One of the reasons i work on a rbd library is just to get more realism in games :) sorry for the long delay, i've been offline for much too long :/ st�le =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
