Simulating smoke and fluids takes a long time.

[MtoH]

read the very bottom of that page...

it's been available for use in Houdini for a couple of years now...I don't know of anyone who has used it though...

Just because it's available doesn't mean I can justify the cost of it. In any case I was just pointing it out, as they looked similar to the 4d noise mentioned above.

[itriix]

hey thanks so much for taking the time to make an example. when i was reading the articles, i had the same issue trying to think about how they could accomplish the transfer from 2d to 3d. i'm proud to say i was definately thinking about multiplying around the y axis like you all are suggesting. the example helps so much more though!

[Netvudu]

whoa, you guys rock. I have yet to check those scenes...something that won

[chumbuk]

this can be done more accurately using a custom Voppop fields + metabols and volume shaders...

tor_field.hip

tor_field.mov

Edited April 25, 2009 by chumbuk

[Jason]

this can be done more accurately using a custom Voppop fields + metabols and volume shaders...

That has an awesome look:) Good stuff!

[itriix]

very nice!!!!!

[pclaes]

this can be done more accurately using a custom Voppop fields + metabols and volume shaders...

Thanks a lot for this, this workflows helps me a lot to clarify how you go about using your rest, ofcet and where to link them up in the shader. Also the maths to get to the tor_field makes sense. It has a very nice feel and look to it, and it's really cool that after all of that you are still just adding your own field to it, which allows for addition of other fields.

[chumbuk]

this is my experiment, there is likely to have errors. This technology is not from tutorials. For example gurus advise metabol-volyume bake in i3d. I then did not do ... etc.

[chumbuk]

variant when the particles are emitted from moved point cloud and "cooled", the mushroom-hat moves up.Particles are cooled by age - attribute, transform emiter transferred in voppop, using the inverted transformation matrix multiplied by P in voppop. From the fact that the particles emit, there is a problem from their initial position at the time of birth, I have decided through the creation of another popsistemy and copying from it attribute "rest". I think this is not an elegant solution ...

Interesting as it is done correctly, without the use of heavy DOPs smok and piro solvers, or if in dops, how to displace the distribution of the density only for a particular vector field, without temperature and distance component?

sory for bad english...

tor_field2.mov

tor_field2.hip

[Netvudu]

Ok. I finally got some time to take a look at all those cool scenes...and now I feel dumber, thank you

Of all the stuff there, I could perfectly follow Peter (pclaes) scene. It made a lot of sense to me, and even though I could tell the whole random rotation thing based on the particle ID was indeed a hack, it looked like a nice trick that could work in many situations. Even the VopPOP is quite easy to reproduce should the need arise.

Brian

[chumbuk]

Vop pop field is realy simply, its vector of velocity at point in space. Usually this vector is a simple function of P. Physically correct to use the resulting vector as the acceleration, but in practice more convenient to use it as a speed(velocity).

For example constant radial field with its center at the origin:

vel = normalize(P)

and vortex field:

nP = normalize(P)

Y = {0,1,0}

vel = cross(nP,Y)

tor field bit dodge but still simple:

x = normalize(cross(P,(0,1,0)))

z = normalize(P*(1,0,1))*radius -P

vel = cross(x,z)

If you take into account other factors and attributes such as age, mass, relative distance etc. I think you can get any result of the order.

simple_vop_fields.hip

Edited April 28, 2009 by chumbuk

[brianburke]

Thanks a lot for breaking that down and setting up that example chumbuk. Really nice stuff.

[simonj]

Yes, nice structured examples chumbuk.