[fonc] s3 slides
Hi, I think there may have been some interest and subsequent difficulty finding copies of my S3 slides. Just in case, I've uploaded them here: http://piumarta.com/papers/S3-2008-slides.pdf Cheers, Ian ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
Ian, Thanks for posting this. The 'Giants' slide (#40) is priceless. This will be very helpful in my evangelizing of this project. Hope all is well. Happy coding. -Cornelius On Thu, Jun 12, 2008 at 5:59 PM, Ian Piumarta <[EMAIL PROTECTED]> wrote: > Hi, > > I think there may have been some interest and subsequent difficulty finding > copies of my S3 slides. Just in case, I've uploaded them here: > > http://piumarta.com/papers/S3-2008-slides.pdf > > Cheers, > Ian > > > ___ > fonc mailing list > fonc@vpri.org > http://vpri.org/mailman/listinfo/fonc > -- Cornelius Toole, Jr. Graduate Research Assistant Louisiana State University Center for Computation and Technology mobile: 601.212.3045 ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
Title: Re: [fonc] s3 slides Folks, On slide #42, Gezira, Shouldn't the top line be Max and not Min? Otherwise every edge contributes at least 1 to every pixel, no matter where it is! Or, am I grossly misunderstanding this? On slide #39, Maxwell's Equations, are you aware that they can be derived from just electrostatics (F = e1*e2/(r1-r2)^2) and the Lorentz transformation of special relativity. "From our present vantage point, the magnetic interaction of electric currents can be recognized as an inevitable corollary of Coulomb's law. If the postulates of relativity are valid, if electric charge is invariant, and if Coulomb's law holds, then the effects we commonly call "magnetic" are bound to occur. They will emerge as soon as we examine the electric interaction between a moving change and other moving charges." Electricity and Magnetism (Berkeley Physics Course - Volume 2) by Edward M. Purcell (1965) p173 This means that magnetism with all its funny properties is simply caused by ordinary charges moving at relativistic speeds (often inside an atom). The existence of a magnet is proof of special relativity. It is also very cool to be able to have a counter-intuitive relativistic effect that you can hold in your hand and play with! --Ted. -- Ted Kaehler http://www.squeakland.org/~ted/ (home) 3261 Montecito Drive, Las Vegas, NV 89120. voice (702) 456-7930 Puzzle: Faucets in a bathroom sink can either have long handles that turn opposite directions, or both can turn counter-clockwise to open. Is there any direction that a hot or cold faucet can turn and be incorrect in both schemes? --Ted. ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
On Fri, Jun 13, 2008 at 9:27 AM, Ted Kaehler <[EMAIL PROTECTED]> wrote: > Folks, > On slide #42, Gezira, Shouldn't the top line be Max and not Min? > Otherwise every edge contributes at least 1 to every pixel, no matter where > it is! Hi Ted, No, "min" is correct. The intention is that every edge contributes at most 1. Using max instead would allow a contribution to exceed one (which would be incorrect). Perhaps there is confusion about what the "min" function does. It returns the minimum of the two arguments. It might erroneously be thought of as returning "at least" the magnitude of the arguments. I'm guessing that that stems from our use of the word minimum in the English language, for example "At a minimum, you just do this..." for setting a lower bound. On the contrary, the min function actually sets an upper bound. It sets the upper bound by restricting the result to be the minimum of the arguments, where one of the arguments usually is an upper bound. Strange, isn't it :) Hope that helps, Dan ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
On Fri, Jun 13, 2008 at 2:00 PM, Dan Amelang <[EMAIL PROTECTED]> wrote: > > No, "min" is correct. The intention is that every edge contributes at > most 1. Using max instead would allow a contribution to exceed one > (which would be incorrect). Whoops! Although what I said about the min function is correct, I wasn't careful about explaining how it fits in with the whole formula. At this point in the formula, we aren't restricting individual edge contributions. We have already summed up the contributions. What we are restricting at this point is the total contribution of the closed path to a given pixel. And that value cannot be greater that 1 (meaning entirely opaque). Sorry for any confusion, Dan ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
On 13.06.2008, at 23:00, Dan Amelang wrote: On Fri, Jun 13, 2008 at 9:27 AM, Ted Kaehler <[EMAIL PROTECTED]> wrote: Folks, On slide #42, Gezira, Shouldn't the top line be Max and not Min? Otherwise every edge contributes at least 1 to every pixel, no matter where it is! Hi Ted, No, "min" is correct. The intention is that every edge contributes at most 1. Using max instead would allow a contribution to exceed one (which would be incorrect). Perhaps there is confusion about what the "min" function does. It returns the minimum of the two arguments. It might erroneously be thought of as returning "at least" the magnitude of the arguments. I'm guessing that that stems from our use of the word minimum in the English language, for example "At a minimum, you just do this..." for setting a lower bound. On the contrary, the min function actually sets an upper bound. It sets the upper bound by restricting the result to be the minimum of the arguments, where one of the arguments usually is an upper bound. Strange, isn't it :) That's a very common thinko. At least I'm always confused by min(max,max(min,x)) ... - Bert - ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
Re: [fonc] s3 slides
Dan, Ah, the problem is that I did not know whether the summation could be larger than 1.0 or not. I see now. --Ted. -- Ted Kaehler http://www.squeakland.org/~ted/ (home) 3261 Montecito Drive, Las Vegas, NV 89120. voice (702) 456-7930 Puzzle: Faucets in a bathroom sink can either have long handles that turn opposite directions, or both can turn counter-clockwise to open. Is there any direction that a hot or cold faucet can turn and be incorrect in both schemes? --Ted. ___ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
