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.

Obviously, the beta grid was not created to be a free for all, play money upload sim for testing our creations. I believe it was created as a server and viewer test environment.
But it is useful for testing the look and function of textures and sculpts when I don’t have a clear idea what they will do inworld. The upload window sculpt preview is really only useful for verification purposes “Yep, it’s a sculpt alright.”
We are making furniture for Second Life. We’ve made that clear. Unsurprisingly, in the beta grid I have seen names I have recognized from other SL furniture businesses.

Upload fees do add up after a while and the beta grid is a great place for our team to meet and critique design ideas and decide if they warrant further exploration. Granted, by that point the time to create a prototype sculpt has already been spent. But let’s face it, sculpting design ideas and texture creation were already play time for me anyway. There is a breaking point there somewhere that in rl would equate to billable hours, but I don’t know where it is.