Any advice to make a slowmo water simulation.

I need to make some splashes in slowmotion, but the camera going through those splashes at normal speed (24fps).

Can someone help me with some ideas of how to do it?

Thanks.

Hi,
Wedge some water splash simulations with extra sub frame data , then do a retime to slow down in houdini , then render with normal speed camera .

Rob

Hi Rob.
Let me see if i understand you, the retime i have to do is to the cache data?

Jason

yup , you will need to do some tests , why not make a simple example scene and read this thread
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=118840&sid=a750b066bbc0d8d5f8a03b8ca982eb06 [sidefx.com]

Rob

https://vimeo.com/112151619 [vimeo.com]
And it works on mesh too. Algorithm：
http://blog.csdn.net/cuckon/article/details/39813787 [blog.csdn.net]

I wonder what would happen if you played with the timescale parameter on the flip solver !

Rob

Thank you both for the advise, ill make some test and let you know how it goes.

Jason

I am doing this now, just make sure that your flip solver creates the ID Atrribute and that you have reseeding turned OFF. This is the most important, as without doing this you will get Particles whose ID's will clash as a particles dies off and a new one is born.

Once the particles are written to disk, append a timeblend and then a timewarp. In the timewarp, you simply remap your in value to your desired value. As a note, this is a linear interpolation so after about 4X you can really start to see it.

TImescale parameter - This works as well but it alters the simulation dramatically, so if you like the look you have then go with the timeblend combo.

There is a way to get quadratic blends using previous and future positions, but I have not yet been able to get a working file…

I made a simple tool for keyframming speed of the animation from Slow to Fast (or opposite) , you can download this tool (JK Time Speed) from my website at :

http://jkcompany.org/JK_Houdini_Tools.html [jkcompany.org]

Just you should simulate your water simulation in slow with Time Scale parameter in the FlipSolver DOP , then save this simulation in bgeo files on the disk.

Finally use my tool for controlling it's speed.

I made a simple project about this for you.
Just please render bgeo files yourself.
and install JK_Time_Speed.otl in your project.

Hey @Sadjad the otl website currently not available right now