Loading...
> >

Fall rate

deleted userdeleted user Posts: 1,204
edited March 2015 in Art Studio

Hi all. I'm doing an animation where a droplet of condensation falls off a glass of cola.
But I'm not sure what a realistic fall rate would be.
My frame rate is set to 20. How fast / far would a droplet fall in 1 second? I want the fall rate to be realistic.

One of them falls so fast it's almost instant, and the other try looks like its on the moon hehe!
I'm having a hard time getting a realistic fall rate.

Post edited by deleted user on

Comments

  • mjc1016mjc1016 Posts: 15,001
    edited December 1969

    FlowerGirl said:
    Hi all. I'm doing an animation where a droplet of condensation falls off a glass of cola.
    But I'm not sure what a realistic fall rate would be.
    My frame rate is set to 20. How fast / far would a droplet fall in 1 second? I want the fall rate to be realistic.

    One of them falls so fast it's almost instant, and the other try looks like its on the moon hehe!
    I'm having a hard time getting a realistic fall rate.

    Sounds to me like the perfect excuse to spend some quality time with a large iced beverage...and a stopwatch. Seriously.


    There's way too many factors involved to say 'this' the real world rate. So either pick some arbitrary setting between those two extremes or sit around watching the variations that happen on a real glass of real cola...

  • Hermit CrabHermit Crab Posts: 841
    edited December 1969

    Hi FlowerGirl,

    When a droplet falls in real life, it will gather speed as it accelerates under the force of gravity.

    After, say, three seconds or sixty frames, the droplet will travel an overall distance which can actually be calculated.

    But because the droplet is accelerating it won't travel one third of the overall distance in the first second and the same distance in each of the following two seconds.

    Because it gathers speed, it will travel a short distance in the first second, then a longer distance for the next second then an even longer distance for the second after that.

    If it is really important to get this right you could measure the distance your drop will travel over time using an established formula.

    It's a long time since I studied this so I'm going from memory and stand to be corrected.

    Objects accelerate due to the force of gravity at the rate of 9.8 metres per second per second.

    (In feet, that's 32 feet per second per second.)

    The formula for measuring distance travelled by an accelerating object is:

    (initial speed multiplied by time) plus half of (acceleration multiplied by time multiplied by time)

    In 1 second your droplet will travel (0 * 1) + (0.5 * 9.8 * 1 * 1) = 4.9 metres .

    If it falls for two seconds it will travel (0 * 2) + (0.5 * 9.8 * 2 * 2) = 19.6 metres

    And so on ...

    That leaves you with the problem of what constitutes a metre in your scene. (Could the cola glass count as one-fifth of a metre?)

    I truly apologise if I've gone over the top here by dredging up things I learned in my school-days.

    When I envisage what you want to do, I can't help feeling that such things are often filmed in slow motion .... aaaargh

  • deleted userdeleted user Posts: 1,204
    edited December 1969

    Nope it helped quite a lot. Thank you.

Sign In or Register to comment.