Combining Pyro and FLIP

[Crypt]

Hi,

I am student at Bournemouth University in MSc computer Animation and Visual Effects. For my Master Dissertation I am making a tool in Houdini that allows to develop a effect on transition of matter means gas to liquid.

I am planning to demonstrate it by showing steam evaporating from a water container, touching on a freezing window glass(its snowing outside) and condensing to water(droplets of water sliding on the window glass and water accumulating at the bottom of the window frame) as it touches the window glass.

For this I am planning to combine PyroFX solver and Flip solver of Houdini to attain this goal.

Starting point for this project should be getting the details how PYRO and FLIP work in Houdini. Is it possible to combine the two....? Would I need extensive use of HDK and VEX....? For conversion of gas to liquid I am planning to use principals of thermodynamics.

I am very new to Houdini so I would like to get your views and suggestion for this topic. Any Help with materials and links for information or sharing your knowledge is appreciable since I have limited time.

[anupamd]

Well in my opinion, it is entirely possible to do the effect you are talking about without having any complex inter-relationships between FLIP/Pyro..etc. If in the end what is important is the visuals, you can have the steam be a pyro, the dew on the window be fluids and so on, and they dont really need to see each other, you can just use crafty placements of emitter with some simple timing and animation.

Its cool from an academic standpoint (which is where you are right now), but from a production standpoint, you just do what works, whatever is fastest and still achieves the look.

BUT if you try a totally procedural approach, you'll probably learn a lot. =) Having said that the key to get different DOP systems to talk to each other is understand how data is passed and how the microsolvers use them. Click on the various nodes in a simple dop sim and look at details view and see what fields are set up. I found Bunkers example files (like his Pyroclastic example file) extremely useful. Also you can find Peter Claes thesis where he in detail talks about such datapassing and DOP relationships with concrete examples.

Finally take a look at Jeff Lait "building a fluids solver" masterclass...(available on sidefx site)

These resources really opened a lot of doors for me, hopefully you will feel the same.

-A

Hi,

I am student at Bournemouth University in MSc computer Animation and Visual Effects. For my Master Dissertation I am making a tool in Houdini that allows to develop a effect on transition of matter means gas to liquid.

I am planning to demonstrate it by showing steam evaporating from a water container, touching on a freezing window glass(its snowing outside) and condensing to water(droplets of water sliding on the window glass and water accumulating at the bottom of the window frame) as it touches the window glass.

For this I am planning to combine PyroFX solver and Flip solver of Houdini to attain this goal.

Starting point for this project should be getting the details how PYRO and FLIP work in Houdini. Is it possible to combine the two....? Would I need extensive use of HDK and VEX....? For conversion of gas to liquid I am planning to use principals of thermodynamics.

I am very new to Houdini so I would like to get your views and suggestion for this topic. Any Help with materials and links for information or sharing your knowledge is appreciable since I have limited time.

[Crypt]

Well in my opinion, it is entirely possible to do the effect you are talking about without having any complex inter-relationships between FLIP/Pyro..etc. If in the end what is important is the visuals, you can have the steam be a pyro, the dew on the window be fluids and so on, and they dont really need to see each other, you can just use crafty placements of emitter with some simple timing and animation.

Its cool from an academic standpoint (which is where you are right now), but from a production standpoint, you just do what works, whatever is fastest and still achieves the look.

BUT if you try a totally procedural approach, you'll probably learn a lot. =) Having said that the key to get different DOP systems to talk to each other is understand how data is passed and how the microsolvers use them. Click on the various nodes in a simple dop sim and look at details view and see what fields are set up. I found Bunkers example files (like his Pyroclastic example file) extremely useful. Also you can find Peter Claes thesis where he in detail talks about such datapassing and DOP relationships with concrete examples.

Finally take a look at Jeff Lait "building a fluids solver" masterclass...(available on sidefx site)

These resources really opened a lot of doors for me, hopefully you will feel the same.

-A

Thanks for the information.

I found some of the interesting examples on fluid simulation at http://physbam.stanford.edu/~fedkiw/.

Here there is one example that shows transition from solid to liquid. Many that shows multiple liquid reacting or liquid cloth/RBD collisions but none that show phase transition.

I am trying to do the following thing

The process of converting involves taking the temperature of the colliding object and making changes to the temperature field of the pyro solver on collision to calculate the change in velocity, density and dissipation. Also to take parameters of density, temperature and heat on collision and generate a map or create points using Kelvin Equation(thermodynamics) that can act as a emitter for flip solver. Further more I want to add more physical attributes of thermodynamics along with options of object melting, burning them, generating dew drops on the humidity parameter, wetmaps, staining burnt objects, etc.

Currently things I have gone through and understood are how the pyro/ flip sovers work. I am aware about the micro solvers but am stuck on how to use them as am not able to find any reading material or tutorials on it. I am going through Peter Claes thesis of his masters project. Are you referring to his MSc Master's Thesis...?

My major questions are::

1) How to use micro-solvers and make them comunicate?

2) How to creates some custom fields like velocity, temperature, density.?

3) How to control effects like diffusion and evaporation on certain voxels only.....?

4) Where can I get reading material in VOP Forces and VOP SOP for more programming based controls?

5) Is it possible to use C++ classes and codes inside Houdini using Houdini HDK.....?

6) Can I create some custom nodes in Houdini where I can write some scripts in Python or HScript...?

7) Where can we use VEX.....?

8) How to relate multiple fileds on custom basis.....?

Pardon me if my questions are stupid as I am quite new to Houdini and effects......!!!

Edited August 5, 2011 by Crypt