Daemon : Filter Expressions

The → "Filter" daemon in RealFlow | 3ds Max allows you to define simple comparisons and conditions, so-called expressions, in order to transfer particles between fluid containers.

Let's assume you want to filter the particles from “Fluid_A” against their velocities. If a particle' speed is lower than 2.0 the particle should be transferred to “Fluid_B”:

  • Target > Fluid_A

  • Source > Fluid_B

  • Condition > Expression

  • Under “Expression” enter: particle.speed<2.0

You can use any other keywords from the table and modify the expression to your needs. It is also possible to combine expressions, e.g. 

  • if particle.age>particle.velocity

 

Attribute

Expression keyword

Age

particle.age, particle.isolation

Collision

particle.collision

Density

particle.density

Force

particle.force.mod, particle.force.x, particle.force.y, particle.force.z, particle.f.mod, particle.f.x, particle.f.y, particle.f.z

ID*

particle.id

Mass

particle.mass

Neighbors

particle.nv, particle.neighbors, particle.neighbours

Normal

particle.normal.x, particle.normal.y, particle.normal.z

Position

particle.pos.x, particle.pos.y, particle.pos.z, particle.position.x, particle.position.y, particle.position.z

Pressure

particle.pressure

Texture

particle.texture.u, particle.texture.v, particle.texture.w

Velocity

particle.speed, particle.velocity.x, particle.velocity.y, particle.velocity.z, particle.vel.x, particle.vel.y, particle.vel.z

Viscosity

particle.viscosity

Vorticity

particle.vorticity.mod, particle.vorticity.x, particle.vorticity.y, particle.vorticity.z

Emitter Idparticle.emitterid*

 

* An emitter's Id can be seen in the HUD.