Shoot.. Sorry, I should have read the initial post thoroughly..
On Tue, Apr 9, 2013 at 10:07 AM, Adam Sale <adamfs...@gmail.com> wrote: > What about the spin particle compound? It has a tumble function.. > > > On Tue, Apr 9, 2013 at 8:20 AM, Andy Nicholas <a...@andynicholas.com>wrote: > >> Hi Morten, >> The only issue with randomising or turbulising it, is that the particles >> will >> look like they're being acted on by some sort of force because their >> angular >> momentum is varying. >> >> If you want something a little more like tumbling debris in zero gravity, >> then >> during emission; store a random unit vector (A) to rotate the particle >> around. >> Use Randomise By Cone to generate another unit vector (B) at 90 degrees to >> vector A, but at a random 360 orientation about it. Store this vector >> too. It >> will be used to rotate vector A on each frame. Finally, store two random >> rates >> of rotation. One for spinning the particle around A, and one for spinning >> A >> around B. >> >> All that stuff is just your initialisation. On each frame you just rotate >> vector >> A using B and one of the rates of rotation (Angle+Axis). Then rotate the >> particle using vector A and the other rate of rotation. >> >> It should look fairly natural, although I doubt it obeys conservation of >> angular >> momentum exactly. >> >> Cheers, >> A >> >> >> >> On 09 April 2013 at 12:38 Morten Bartholdy <x...@colorshopvfx.dk> wrote: >> >> >> > Which is the best method to make totally randomly tumbling particles in >> ICE? I >> > am doing it with Spin Particle and altering the input axis with >> Randomizing >> > the rotation by cone. I am thinking I would like to turbulize direction >> of the >> > the vector instead of randomizing but have not cracked that one yet. >> > >> > Is there a more elegant way to make particles tumble (flying slowly >> through >> > the air) totally randomly? >> > >> > Morten >> > >> > >> > >> > >
