detecting the speed of a particle

  • xx_mortekai_xx
    3rd Mar 2012 Member 0 Permalink
    Im trying to have a substance act differently depending on the speed at which it is struck with a neutron.  Is there any way to directly detect the speed or velocity of a particle that would help me in this context?
  • Minishooz
    3rd Mar 2012 Member 0 Permalink
    @xx_mortekai_xx (View Post)

    I once made a photon speed meassure. It used a detector and counter to test how fast it went by timing how long it took to get back. It had a digital display and was ready to be published when I accidentaly deleted it :(
  • The-Con
    3rd Mar 2012 Member 0 Permalink
    @xx_mortekai_xx (View Post)
    You can observe the number of pixels the particle travels at 61 fps, then divide that by the time it takes. For example, a photon will generally go about 20 pixels per second.
    Otherwise, I have a timer that is inaccurate :P

    Or use the code...
  • Mushroom
    3rd Mar 2012 Member 0 Permalink
    @The-Con
    To obtain a stable speed value with any fps, don't divide with the time in seconds but in frames, you can measure them with pressing f (which is quite slow).
    Using that time base should allow to make precise measures without the fps influence.
  • The-Con
    3rd Mar 2012 Member 0 Permalink
    @Mushroom (View Post)
    That's what I meant...kind of.
    I am calculating the speed of PHOT based on the fact that it will travel 3 pixels per frame, therefore 20 (20.3) pixels per second at 61 fps. I use 61 as it is standard.
    You have to use time, otherwise it isn't speed, according to physics.
    However I can't divide by time, as fps is already frames per second

    fps/3 = speed of PHOT per second
    61/3 = 20.3 pixels s^-1

    @xx_mortekai_xx
    If you are making an element, you should do it based on the standard and automatic fps, which is 61.
  • Mushroom
    3rd Mar 2012 Member 0 Permalink
    @The-Con
    Fps is the speed of the computer, if you take a common base (61), then that is ok.
    But if you want to measure the speed at, for example, 30 fps, you will find a different value.

    That's why I suggested to use a value that doesn't change depending on the fps.
    If the photon move 3 pixels by frame at 61 fps, it will also move at 3 pixels by frame at 30 fps.
  • The-Con
    3rd Mar 2012 Member 0 Permalink
    @Mushroom (View Post)
    Ah... I see what you are saying now... I think
    But there is that major point that the pixel s^-1 is designed to be 61, not any more or less, so it must be assumed that one is simulating at the desired rate.
  • lillepallt
    3rd Mar 2012 Member 0 Permalink
    While we're om point, why have I never seen anyone declare frames as measurement of time instead of seconds and minutes. I hate it when people give you a value of minutes or seconds because if your save run at 60fps it takes double the time for someone running it at 30fps. It extremely easy to calculate time and frames, to calculate frames just take fpsrate • seconds and to calculate seconds use number of frames / fpsrate Just pointing that out
  • mniip
    3rd Mar 2012 Developer 0 Permalink
    @lillepallt (View Post)
    Its same useless that measuring tpt srcreen in inches or centimeters, the conversion is same easy as yours, but for some reason noone uses it
  • The-Fall
    3rd Mar 2012 Member 0 Permalink
    Well if your really up tp it, simply modify the statement dictating what particle VX, and VY are and include the declaration of an Array, then have the array have the values of VZ VY for one particle output to a text file, or seperate section within TPT.