All the fluids simulation, if I'm not wrong, have to be emitted inside a container. The reason for this to happen is it because in physics, a fluid is generally regarded as a continuum, rather than a bunch of individual molecules?! Where by doing this we can manipulate them by adding values to different sections of the containers. I mean where a combustion and different parameters can take place, interacting with each other  manipulating the simulation. Is this idea right?
But why Realflow doesn't need a container is something that I'm trying to understand. Is it because each particle represents an element of liquid mass? I'm getting a little confuse.
Thanks
Why Realflow doesn't have a container?
 Vitor Teixeira
 Posts: 312
 Joined: Thu Jul 23, 2009 1:47 pm
 Location: Porto, Portugal
 Contact:
Why Realflow doesn't have a container?
It's matter of algorithm used.
Eulerian gridbased fluids are defined in a container,
RF's SPH (Smoothedparticle hydrodynamics) do not need one (and any other software as well).
As Calibrix said In this topic, You will see such container soon :)
NEW Hybrid Based Fluids Solver
This NEW solver will allow you to simulate medium to largescale fluids. In the core is a gridbased solver that automatically detects those areas where more resolution is needed, and creates particles that will then be simulated using our standard particlebased solver. Additional details like foam or mist, and even displacement maps, can be created as well.
Eulerian gridbased fluids are defined in a container,
RF's SPH (Smoothedparticle hydrodynamics) do not need one (and any other software as well).
As Calibrix said In this topic, You will see such container soon :)
NEW Hybrid Based Fluids Solver
This NEW solver will allow you to simulate medium to largescale fluids. In the core is a gridbased solver that automatically detects those areas where more resolution is needed, and creates particles that will then be simulated using our standard particlebased solver. Additional details like foam or mist, and even displacement maps, can be created as well.
"Do not feed the trolls"
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital

 Posts: 2880
 Joined: Mon Oct 15, 2007 4:09 pm
 Contact:
Why Realflow doesn't have a container?
Fluid simulations that require a "container" are usually grid based solvers like NavierStokes for fire and smoke. RealFlow uses smoothed particle hydrodynamics (SPH) which is not the same thing and is not based on a grid. There's quite a lot of information out there about SPH, but this is a good place to start.
http://en.wikipedia.org/wiki/Smoothedparticle_hydrodynamics
SPH is not the only method to simulate liquids but it is probably one of the best methods to simulate liquids for CG and visual effects because of its relative flexibility compared to other methods. Cheers!
http://en.wikipedia.org/wiki/Smoothedparticle_hydrodynamics
SPH is not the only method to simulate liquids but it is probably one of the best methods to simulate liquids for CG and visual effects because of its relative flexibility compared to other methods. Cheers!
 Vitor Teixeira
 Posts: 312
 Joined: Thu Jul 23, 2009 1:47 pm
 Location: Porto, Portugal
 Contact:
Why Realflow doesn't have a container?
So Reaflow uses an Lagrangian approach right?
What other SPH are out there?
ICE from softimage?
What other SPH are out there?
ICE from softimage?

 Posts: 2880
 Joined: Mon Oct 15, 2007 4:09 pm
 Contact:
Why Realflow doesn't have a container?
Vitor Teixeira wrote: So Reaflow uses an Lagrangian approach right?
What other SPH are out there?
ICE from softimage?
There's glu3D for Max, the ICE SPH stuff from Thiago and Grant for Softimage XSI, Houdini has an SPH solver out of the box, and then there's a lot of solvers out there not related to CG.
This isn't out yet but its wroth looking into if you're interested in other simulators. Knowing the work of the individuals leads me to believe its not SPH though.
http://www.exoticmatter.com/overview/
 Vitor Teixeira
 Posts: 312
 Joined: Thu Jul 23, 2009 1:47 pm
 Location: Porto, Portugal
 Contact:
Why Realflow doesn't have a container?
As they are particle based it's correct to say they use an Lagrangian approach.
Inside particle based we have SPH are there any others?
And inside the grid based?
I'm not understanding well where the Navier Stokes fills in
Inside particle based we have SPH are there any others?
And inside the grid based?
I'm not understanding well where the Navier Stokes fills in
Why Realflow doesn't have a container?
After little google digging I've collected some more informations for You:
NavierStokes Equasions, describe the motion of fluid it can be adapted in many techniques
Heightfield Fluids(for e.g. Realwave)
Represent fluid surface as 2D function (and problem is that it can have one value per (x, y) = no breaking waves)
Lagrangian methods
Lagrangian specification of the flow field is a way of looking at fluid motion where the observer follows an individual fluid parcel as it moves through space and time
Particle based, Meshfree method
Meshfree methods eliminate some or all of the traditional meshbased view of the computational domain and rely on a particle (either Lagrangian or Eulerian) view of the field problem.
 SPH (1977) (smoothed Particle Hydrodynamics) invented for simulation of stars, used for simulating fluid flows.
The smoothedparticle hydrodynamics (SPH) method works by dividing the fluid into a set of discrete elements, referred to as particles
The following numerical methods are generally considered to fall within the general class of "meshfree" methods. Acronyms are provided in parentheses.
â–ª Smoothed particle hydrodynamics (SPH) (1977)
â–ª Diffuse element method (DEM) (1992)
â–ª Elementfree Galerkin method (EFG / EFGM) (1994)
â–ª Reproducing kernel particle method (RKPM) (1995)
â–ª hpclouds
â–ª Natural element method (NEM)
â–ª Material Point Method (MPM)
â–ª Meshless local Petrov Galerkin (MLPG)
â–ª Moving particle semiimplicit (MPS)
â–ª Generalized finite difference method (GFDM)
â–ª Particleincell (PIC)
â–ª Moving particle finite element method (MPFEM)
â–ª Finite cloud method (FCM)
â–ª Boundary node method (BNM)
â–ª Boundary cloud method (BCM)
â–ª Method of fundamental solution(MFS)
â–ª Method of particular solution (MPS)
â–ª Method of Finite Spheres (MFS)
â–ª Discrete Vortex Method (DVM)
Related methods:
â–ª Moving least squares (MLS)  provide general approximation method for arbitrary set of nodes
â–ª Partition of unity methods (PoUM)  provide general approximation formulation used in some meshfree methods
â–ª Continuous blending method (enrichment and coupling of finite elements and meshless methods)  see Huerta & FernÃ¡ndezMÃ©ndez (2000)
â–ª eXtended FEM, Generalized FEM (XFEM, GFEM)  variants of FEM (finite element method) combining some meshless aspects
â–ª Local MaximumEntropy (LME)  see Arroyo & Ortiz (2006)
â–ª SpaceTime Meshfree Collocation Method (STMCM)  see Netuzhylov (2008), Netuzhylov & Zilian (2009)
â–ª Meshfree radial point interpolation method (RPIM)
Eulerian gridbased methods
The Eulerian specification of the flow field is a way of looking at fluid motion that focuses on specific locations in the space through which the fluid flows
 volume of fluid method (VOF)
 Lattice Boltzmann methods (LBM)
BGK (BhatnagarGrossKrook) model
MRT (MultipleRelaxationTime) model
Regularized model
Entropic model
"Instead of solving the Navierâ€“Stokes equations, the discrete Boltzmann equation is solved to simulate the flow of a Newtonian fluid with collision models such as BhatnagarGrossKrook (BGK). By simulating streaming and collision processes across a limited number of particles, the intrinsic particle interactions evince a microcosm of viscous flow behavior applicable across the greater mass."
Blender 3d uses Lattice Boltzmann method
NavierStokes Equasions, describe the motion of fluid it can be adapted in many techniques
Heightfield Fluids(for e.g. Realwave)
Represent fluid surface as 2D function (and problem is that it can have one value per (x, y) = no breaking waves)
Lagrangian methods
Lagrangian specification of the flow field is a way of looking at fluid motion where the observer follows an individual fluid parcel as it moves through space and time
Particle based, Meshfree method
Meshfree methods eliminate some or all of the traditional meshbased view of the computational domain and rely on a particle (either Lagrangian or Eulerian) view of the field problem.
 SPH (1977) (smoothed Particle Hydrodynamics) invented for simulation of stars, used for simulating fluid flows.
The smoothedparticle hydrodynamics (SPH) method works by dividing the fluid into a set of discrete elements, referred to as particles
The following numerical methods are generally considered to fall within the general class of "meshfree" methods. Acronyms are provided in parentheses.
â–ª Smoothed particle hydrodynamics (SPH) (1977)
â–ª Diffuse element method (DEM) (1992)
â–ª Elementfree Galerkin method (EFG / EFGM) (1994)
â–ª Reproducing kernel particle method (RKPM) (1995)
â–ª hpclouds
â–ª Natural element method (NEM)
â–ª Material Point Method (MPM)
â–ª Meshless local Petrov Galerkin (MLPG)
â–ª Moving particle semiimplicit (MPS)
â–ª Generalized finite difference method (GFDM)
â–ª Particleincell (PIC)
â–ª Moving particle finite element method (MPFEM)
â–ª Finite cloud method (FCM)
â–ª Boundary node method (BNM)
â–ª Boundary cloud method (BCM)
â–ª Method of fundamental solution(MFS)
â–ª Method of particular solution (MPS)
â–ª Method of Finite Spheres (MFS)
â–ª Discrete Vortex Method (DVM)
Related methods:
â–ª Moving least squares (MLS)  provide general approximation method for arbitrary set of nodes
â–ª Partition of unity methods (PoUM)  provide general approximation formulation used in some meshfree methods
â–ª Continuous blending method (enrichment and coupling of finite elements and meshless methods)  see Huerta & FernÃ¡ndezMÃ©ndez (2000)
â–ª eXtended FEM, Generalized FEM (XFEM, GFEM)  variants of FEM (finite element method) combining some meshless aspects
â–ª Local MaximumEntropy (LME)  see Arroyo & Ortiz (2006)
â–ª SpaceTime Meshfree Collocation Method (STMCM)  see Netuzhylov (2008), Netuzhylov & Zilian (2009)
â–ª Meshfree radial point interpolation method (RPIM)
Eulerian gridbased methods
The Eulerian specification of the flow field is a way of looking at fluid motion that focuses on specific locations in the space through which the fluid flows
 volume of fluid method (VOF)
 Lattice Boltzmann methods (LBM)
BGK (BhatnagarGrossKrook) model
MRT (MultipleRelaxationTime) model
Regularized model
Entropic model
"Instead of solving the Navierâ€“Stokes equations, the discrete Boltzmann equation is solved to simulate the flow of a Newtonian fluid with collision models such as BhatnagarGrossKrook (BGK). By simulating streaming and collision processes across a limited number of particles, the intrinsic particle interactions evince a microcosm of viscous flow behavior applicable across the greater mass."
Blender 3d uses Lattice Boltzmann method
"Do not feed the trolls"
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital
 Vitor Teixeira
 Posts: 312
 Joined: Thu Jul 23, 2009 1:47 pm
 Location: Porto, Portugal
 Contact:
Why Realflow doesn't have a container?
This is huge. Fantastic quite impressive.
I'm going to take a look.
I'll ask anything later if I need to.
Can you give me some links of this information. It's mainly because I'll need to prove where I got this information. For reasons connected to the bibliography in the dissertation. I'm sorry if I'm asking a lot.
It's ok if you don't have the time.
Really thank you
I'm going to take a look.
I'll ask anything later if I need to.
Can you give me some links of this information. It's mainly because I'll need to prove where I got this information. For reasons connected to the bibliography in the dissertation. I'm sorry if I'm asking a lot.
It's ok if you don't have the time.
Really thank you
Why Realflow doesn't have a container?
About different mesh free methods:
http://en.wikipedia.org/wiki/Meshfree_methods
http://www.springerlink.com/content/f505n82805687324/
about Lattice Boltzmann:
http://en.wikipedia.org/wiki/Lattice_Boltzmann_Method
http://www.lbmethod.org/
http://en.wikipedia.org/wiki/Meshfree_methods
http://www.springerlink.com/content/f505n82805687324/
about Lattice Boltzmann:
http://en.wikipedia.org/wiki/Lattice_Boltzmann_Method
http://www.lbmethod.org/
"Do not feed the trolls"
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital
Albert 'tmdag' Szostkiewicz
FX Technical Director
Weta Digital
 Vitor Teixeira
 Posts: 312
 Joined: Thu Jul 23, 2009 1:47 pm
 Location: Porto, Portugal
 Contact:
Why Realflow doesn't have a container?
Thanks a lot Albert for having the time to give that.
I really appreciate your help.
Luke I talked with Robert Bridson he told that the product will probably will be available to buy in the next summer to Mac and Linus, with support focused on Fedora versions similar to Maya. Is Fedora a lot different from Ubuntu?
Cheers
I really appreciate your help.
Luke I talked with Robert Bridson he told that the product will probably will be available to buy in the next summer to Mac and Linus, with support focused on Fedora versions similar to Maya. Is Fedora a lot different from Ubuntu?
Cheers
Return to “RF4: General topics”
Who is online
Users browsing this forum: No registered users and 1 guest