Distance between particles

[duke3d]

Hello!

According to the Help of Realflow distance between particles can be found like this: radius = 1.0 / (1000.0 · Resolution^1/3) (in meters)
So, for resolution 1.0 distance is 0.001. For the resolution 2.0 distance is 0.000794.

Emitter is a square, 1m*1m.
When I calculate the distance with a script like this:

dom = scene.get_PB_Emitter("Square01")

p_1 =dom.getParticle(1)
p_2 =dom.getParticle(2)

pPos_1 = p_1.getPosition()
pPos_2 = p_2.getPosition()
Dist = pPos_1 - pPos_2

d = Dist.module()
print (str(d))

scene.setGlobalVariableValue("defDist", d)

(or if I use just d = pPos_1.distance(pPos_2))

the result is always 100 times more then it should be. instead of 0.001 for resolution 1.0 I get 0.1. For resolution 2.0 I get 0.0794 instead of 0.000794, and so on. I've tried it with Dyverso particles and I got the same results.
Am I doing something wrong?

[Thomas Schlick]

Just an idea, but what's your scene scale?

[duke3d]

Just an idea, but what's your scene scale?

Scale is default, 1.0

[Thomas Schlick]

Argh... Wanted to add another note, but deleted the post by accident

Ok, the result of 0.1 m is correct. In a square of 1m x 1m and a resolution of 1.0 you have exactly 100 particles. So, the distance between each particle is 0.1 m.

You've compared distance with radius. It's true that resolution affects radius and distance, but this doesn't mean that radius == distance. Otherwise the particles wouldn't be able to collapse under the influence of gravity, and parameters like Int/Ext Pressure wouldn't have any effect. And you can see that particles can get very close in a fluid with resolution = 1.0.

[duke3d]

Oh I feel a bit shame now )) I misunderstood the particle radius term ))) Thanks for clarification
By the way I was looking of some way to get initial distance between particles before the simulation is lunched Zero frame usually has no particles (unless Emitter's volume parameter is set to something more then 0) and I can't find distance between particles. Do you have any suggestions?

Thank you for helping
Andrey

[Thomas Schlick]

Well, you can simply create an initial state from frame 1 or 2 or whatever. Then you'll have particles at frame 0.

[duke3d]

Well, you can simply create an initial state from frame 1 or 2 or whatever. Then you'll have particles at frame 0.

Oh, it make sense

Thank you