Math melts my brain

May 22, 2008

SL rotations have been quite mysterious to me. Their specific relevance to me is in the fact that they are used as a llSitTarget parameter. In my studying of them (and related topics) I have learned what radians are, and grads, and the relationship between radians, grads, degrees and your garden variety circle. I am beginning even to glimpse why rotations are used in SL instead of just using degrees in a normal vector (I mean, I understand vectors), though I have no idea what gimbal lock is.
My understanding of SL rotations, as given in the LSL wiki is thus: The rotation is composed of four floats. The first three floats can be thought of as a vector, which I guess means that, in essence, they are a vector. So those first three floats describe, in radians, a direction in space. One radian is equal to 180 degrees divided by PI, or 57.296 degrees.
The first trick is to understand what a radian is and how to use it. Then to know that the fourth float describes a rotation around the direction (as an axis?) described by the first three.
These are all the words. I have yet to put them together into a clear mental picture of how a rotation works. Bah! This is all just an invention anyway, to help us understand why the toast always lands jam side down.


May 15, 2008

As the “San Jose” informal meeting benches near their completion, we decided to make a test run last night and see how the sit targets work when the bench works under full load. First Ivanova rezzed our grumpy-as-evah green sidekick. Then I asked my friends Trinity and Zylina over. The seating arrangement worked out well, the spacing of the avatars was pleasant and not too cozy. We briefly discussed whether a 6th seat target should be included, but that would have been too tightly packed. We also did not get any script errors, which was nice too.

After that we ran the available designs by Trinity and Zylina, and they both were full of praise. Since I know them as honest friends, I think they meant it that way.

The image shows the San Jose in the new “Poppy” design, other available flavors include Anthracite, Cotton, Denim, Green, Ocean, Red, Royal, Suede and Velvet. More images on Flickr.