Fabien Sanglard's non-blog



February 23, 2011.

Cannot see the menu in Fluid2 ?

In Fluid2 the menu does not appear automatically: You can bring it up by pressing FIVE FINGERS simultaneously on the screen :) !

October 26th, 2011.

iOS 5 iPad: Disabled "album" button :( !

I've received numerous emails mentioning Fluid and Fluid2's "Choose from album" button is disabled for iPad users. The issue has been identified and and updated version has been sent to Apple. It should be out shortly ;) !

April 12, 2011.

iPad "Change background" bug

I've received numerous emails from users mentioning they cannot select a picture from an album since they updated to iOS 4.3.1. It seems the last update broke this feature, but I have fixed this issue now and submitted a new build to Apple, hopefully it will be approved soon.

July 02, 2010.

iOS 4 crash :( !

I've received numerous emails mentioning Fluid and Fluid2 crash on second launch after updating to iOS 4. I've worked around the clock to generate a patch and it is now sent to Apple. I've also contacted the hotline so it will be considered an emergency fix. I keep my finger crossed it won't take too long to get to you guys.

June 29, 2009.

Is "Fluid" too fast ?!

A few person emailed me since the released of "Fluid v1.3". It seems that it is running too fast now. The reason this issue was undetected is that I am doing all my testing on my personnal iPhone (First generation). Fluid v1.3 is using the optimized engine of "Fluid 2" but I did not notice the change until I saw the application running on my friend's 3GS.

The solution

I'm getting a 3GS from the Apple Store this afternoon, I will release a fix tonight: "Fluid v1.4" and "Fluid 2.1". The speed will be constant with ability to control it further via a slider. I hope Apple won't take forever to released them.

Screenshot of the upcoming update

June 9, 2009.

3,000,000 downloads...version 2.0 released !

I am very proud to announce the release of "Fluid 2" on the Appstore ! Check it out:

More freedom on the menu:

May 14, 2009.

1,000,000 downloads...version 1.2 coming !

Never I would have expected so many downloads. I've received numerous positive review for the version 1.1 of Fluid.
I'm working hard on fixing every bug reported, I just sent the version 1.2 to Apple:

Next week, I will keep fixing bug in order to release a version 1.3...and also "Fluid Premium". Stay tuned.

May 9, 2009.

700,000 downloads...and counting !

Not bad for what was supposed to be just a "demo" during my job hunting process.
A lot of people have asked for a music and ability to change the background. Version 1.1 is currently being reviewed by Apple and will allow this:

April 15, 2009.

The actual stuff

I finally finished "Fluid", a FREE interactive water simulation for iPhone. While it is being reviewed by Apple, here is a short article describing how it's done....and the source code ;) !

Download for iphone:


This water simulation uses a very old algorithm based on two heightmaps:

	#define CURRENT_HEIGHTMAP (* simulation1)
	#define PREVIUS_HEIGHTMAP (* simulation2)

	for(x=1; x<=FLOTSIZE; x++)
	for(y=1; y<=FLOTSIZE; y ++)
		//Drag (otherwise water never stop moving)


And that's it! Set an initial height perturbation in the last state, iterate at 30fps: Voila des vagues !


From the heigthmap, we then generate a mesh. Assuming that every pixel ray come to the mesh at (0,0,-1), we can generate a perturbated View Vector. We use these pertubated vectors to offest the textures coordinates.


Right now, only reflection and refraction are simulated via a bottom texture and an environment map texture. The rendition requires two passes.
I tried to add the caustics but without multi texturing, this would have requiered a third pass, unafforable for now.

Running at 30fps:

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Comments (96)

#1 - Eric - 11/06/2010 - 05:28
Dear Fabien,

With fluid 2, it is impossible to change background with a picture taken with iPhone 4. Indeed, the screen becomes dark and fluid 2 is then totally impossible to revers back to one of the stones background. The only solution is to delete the application from the iPhone and then to reinstall it through tune.

I am disappointed!


#2 - Carlos - 11/07/2010 - 22:11
What is the music on your fluid 1 app? or what is the name of the band?
#3 - Fabien Sanglard - 11/08/2010 - 11:36
The name of the music is "Ghost - Lullaby"
#4 - Glen England - 11/13/2010 - 01:50
I really love Fluid and Fluid 2 for the iPad. I would really love to see an Android version developed. Your application is so much fun and is so soothing. My 5 year old daughter loves it and in Fluid 2, she loves seeing her photo as the background too.

Thanks for a great app.
#5 - Franz - 11/15/2010 - 09:01
I like Fluid. It's my First App on iPad. But Why can I not use it on a Projektor or Beamer?
#6 - Gene - 12/06/2010 - 10:32
How do I stop the app to change options? I touch n hold but just ripples the water...cool but. I double touch but...:)
#7 - Fabien Sanglard - 12/06/2010 - 10:48

You can access the option panel by pressing 5 fingers on the screen.


#8 - Maurice - 12/23/2010 - 18:50
Can i use as background or is it just a moving scene?

Hope to heat zoon. Looks very good i,m impressed!
#9 - Fabien Sanglard - 12/23/2010 - 19:04
Not for background, it is not do-able with the public API. If Apple allows it, I will add the feature.
#10 - Dr. Dan Dunne - 12/29/2010 - 18:07

1. Add more zen music (especially without the voice)

2. Give me the capability of adding (or attaching to) my own music.
#11 - Jonas Harms - 01/14/2011 - 12:28
Hey its a really nice app that you have created there but i got a question about Fluid 2.How can i switch to the Home display of Fluid 2 to change the Background or etc.???

Thank you very much
Greeetings Jonas Harms
#12 - Fabien Sanglard - 01/14/2011 - 15:36

You can access the option panel by pressing 5 fingers on the screen.


#13 - Cruisideuce - 01/15/2011 - 09:41
This little app made me buy my iPod touch.
#14 - sebastian castro - 01/15/2011 - 16:27
HI i love this app its so relaxing, very realistic, i would like that u can add your own music and that you can set lock screen. would be awsome. regard from spain.
#15 - jon filbert - 01/15/2011 - 22:06
please tell me you have this for droid .... i have it on my itouch and love it...
#16 - Upstate Steve - 02/01/2011 - 22:28
I just posted this comment on iTunes:

I find this app extraordinarily appealing and soothing, with one exception -- every time I start it up, the music comes on, even though I have set the switch to OFF and it shows up as OFF. So every time -- I have to go to the option panel (tap with all five fingers), turn the music ON, then back OFF. Next time I start the app, of course, the same thing all over, again and again and again. Make it stop!!!!!!!!!

I can only give it 3 stars because of this -- even considered a lower number -- but it would easily be 5 otherwise. [end of iTunes comment]

I have uninstalled the app and then re-installed it twice, but no change. I would use it much more often, but I am so annoyed at the music playing at this bug that I often avoid it.
#17 - Beth - 02/24/2011 - 13:04
I've had this ap since the first version. The latest update, however, will NOT transfer to my itouch. I check it to put it on the iPod, yet when I update, itunes unchecks it. Can you help - is this being fixed. I really liked this app - what happened?
#18 - Fabien Sanglard - 02/24/2011 - 13:14
Beth, make sure your iTouch firmware is updated to the latest version.
#19 - Scott mcglinn - 03/07/2011 - 12:54
I've had since 1st version,
I'm impressed.
Thank you
#20 - Ming Huang - 03/07/2011 - 16:06
Hi Fabien,

I've got the Fluid 2 and really love the realistic rendering of the water effect.

I wonder if you could point me to the "very old algorithm" you've used. Is OpenGL used in your app?

I'm thinking about adding water ripple effect to an app I will work on. Any light you shed on this will be highly appreciated.

Best regards,
#21 - W. Williams - 03/12/2011 - 16:07
I upgraded my iPad to the 4.3 OS last night. Today I downloaded Fluid (free version) and tried to use a photo from my album as a background. It didn't work. Then I bought Fluid2 so I could do this, and I still can't. What is wrong? I'm really disappointed because this is a cool app, but it will be much cooler if I can change the background. Thx.
#22 - Ryan Nguyen - 03/16/2011 - 19:46
Dear Staff-

I just got Fluid 2 after download, I able to turn it on to change the color.... After I confirm the color change I get out the program. When I get back, I won't able to see reset box....

Please kindly help!

Best, Ryan
#23 - Ron Vestal - 03/22/2011 - 22:55
I have the IPAD 2 and using this app, I can't download a picture from IPHOTO. It works fine on my Iphone 4 but not IPAD 2. Please fix so i can enjoy on IPAD's bigger screen.
#24 - shea - 03/24/2011 - 22:38
i just got the ipad2 and the fluid 2 i like it but how do you change the background image
#25 - Andy Gilmour - 03/31/2011 - 07:11
Hi I purchased Fliuid 2when it first came out and it had a fault can you tell me if I can get it back on my phone free of charge thank you A Gilmour
#26 - David - 04/04/2011 - 00:24

I loved your blog about fluid app for iPhone. I didn't quite understand how you did it even with your explanation.
I hope to make an iPhone like ghis or ibeer but have no idea how to do it. Ibeer also simulates fluid.
Any advice or code would be gratefully received.
#27 - Bonnie Rottstin - 04/04/2011 - 15:29
I can no longer use my own picture in the background (on an Ipad 2) It opens in upper left a box (that points upwards off the screen) and says photo album, but I can't open it to select a picture.
#28 - Yas - 04/10/2011 - 13:07
Its lovely sweet app the problem with the new ISO 4.3.1
I am unable to change the background dispute unistall and reinstall it's the same a requist to the developers please reassess and improve
#29 - Amirali Montakhab - 04/18/2011 - 15:51
I bought fluid 2 and when i choose album the pictures folder would not show like fluid 1.
#30 - Fabien Sanglard - 04/18/2011 - 16:11
@Amirali: Fluid1 has been approved before Fluild2 by Apple. Please be patient, it should be published this week ;) !
#31 - AndreB233 - 04/20/2011 - 06:48
Any chance in a near future to get the "Looney", Canadian Dollar as an option?
#32 - varun - 05/09/2011 - 13:19
Great stuff as always, could you please make available the source for fluide available for download.
#33 - jim thomas - 05/16/2011 - 22:45
Please port Fluid to the Xoom. Thanks!
#34 - Carol Kaercher - 05/27/2011 - 08:25
After buying Fluids2 for my Iphone 3gs, it worked one time then froze, I had to delete the application
#35 - Saleh - 05/29/2011 - 00:42
Hi, Fabien,
I have a great idea for fluid, though I am not a developer.
#36 - jonmfilbert - 06/01/2011 - 01:51
any love for the droid yet...? think about the cash your missing...PLEASE PLEASE PLEASE
#37 - Karen Castaneda - 06/06/2011 - 21:43
My husband would like to know the name of the song playing in the background of fluid

Thank you,

#38 - Fabien Sanglard - 06/07/2011 - 11:20

Tell hubby the name of the song is "ghost lullaby".
Also tell him he seems to have a keeper and he should treat her some champagne and flowers this week ;) !
#39 - Bill - 06/08/2011 - 07:05
As a therapist I use Fluid on my iPad for mood enhancement. Is the facility to use one's own iPod music now available on Fluid 2? Only on free one so far but will upgrade if this facility is now available.
#40 - Fabien Sanglard - 06/08/2011 - 12:24

Fluid2 only features enhancements. Everything you can do with Fluid you can do it with Fluid2.
#41 - Ed - 07/01/2011 - 17:14
Awesome ap, just needs to be able to use the live video from the back of the iPad
#42 - Patrick - 07/02/2011 - 00:30
Love this app.  Very calm, soothing, hypnotic.  Just wish it had a timer or the ability to play longer.  I like to put it on next to the bed, great ambient noise, especially when traveling.  Can you add a timer, or make it play for an hour or two ?. Thanks!
#43 - Keriberi - 07/13/2011 - 20:39
I purchased fluid 2, and can't get the menu to pop up. Any suggestions?
#44 - Fabien Sanglard - 07/14/2011 - 15:03

You can access the menu with five fingers on the screen.

#45 - javier - 07/18/2011 - 12:29

Just i have buying Fluid 2 for iphone 4 but i don't get open settings.

I can't change the image..

What am i doing wrong?

#46 - Bilavschi lucian - 07/20/2011 - 05:12
Dear Fabien,

With fluid 2, it is impossible to change background with a picture taken with iPhone 4. Indeed, the screen becomes dark and fluid 2 is then totally impossible to revers back to one of the stones background. The only solution is to delete the application from the iPhone and then to reinstall it through tune.

I am disappointed!


#47 - Varun Pant - 08/02/2011 - 16:44
Still waiting for the source.. :)
#48 - Fernando Rodriguez - 08/25/2011 - 08:46
You mentioned that the source was available, but I can't seem to find it.
#49 - Nukoma - 08/30/2011 - 18:46
What is the song on this app???:)
#50 - Lori - 09/15/2011 - 01:30
I would like to know the name of the background music and artist name on the free fluid version. Great music that i would like to purchase.
#51 - Audsnends - 09/22/2011 - 06:35
I love this app the music is so calming and to my surprise my cat becomes very affectionate when it's playing. Too, it's the the only moving picture on my iPad that doesn't scare her away.

The only improvement I can think of for the app is a timer, so that I can drift off to sleep while it's running.

Great work, thanks.
#52 - manish - 09/30/2011 - 02:52
Hi Fabien,

#define CURRENT_HEIGHTMAP (* simulation1)
#define PREVIUS_HEIGHTMAP (* simulation2)

in this can you give detail about simulation1 and simulation2?
#53 - Luis - 09/30/2011 - 13:57
I think you should make so we could choose our own music and,have an option to make the water flow like a river and when you move the water with you hand it should make the sound of you splashing water........just some ideas
#54 - Митя - 10/08/2011 - 15:05
О!!!яя дас ист натурлих!!!
#55 - Zee - 10/22/2011 - 17:53
Since upgrading to iOS5 I Amon longer able to select a photo from my album.
#56 - Ptbc - 10/23/2011 - 18:58
Still can not change backgroud image from album and take picture by the camera in app fluid 2 on iPad2 iOS5. Fix it or stop selling it.
#57 - Ptbc - 10/24/2011 - 18:07
iOS5 iPad2 - impossible to change backgroud from album or take picture with camera. Why. I paid or the app.
#58 - Mark Erwin - 10/26/2011 - 09:05
Have Fluid 2 - "choose from album" button does not take me to photo album. Cannot find way to use one of my own images as background. Am now using iOS5 but this problem existed prior to that.
#59 - Manda - 11/03/2011 - 01:22
I love this app so much. I feel myself start to relax in seconds, which is a small miracle. Thank you so much Fabien. And I see all your kind answers to ppls questions. What a guy! I hope the ppl in your life appreciate your product!
#60 - Boriyxon - 11/12/2011 - 12:56
It's really cool,but its a little fast in slow mode,please add some slower speed....
#61 - David - 11/20/2011 - 07:50
Love Fluid2 its great what is the name of the song in Fluid2 ?

#62 - Mikel - 12/02/2011 - 09:59
Hello Fabien,

Great product. Thank you very much for your efforts!

I've noticed that many have inquired about custom tunes but I've seen no response from you about this.

Are you planning on adding such functionality to the app?

I believe you would gain many new loyal customers if you did. :)

Best Regards,
#63 - Fabien Sanglard - 12/02/2011 - 17:46

You can use your own songs by turning off the music in the application menu. For now I am not planning on shipping the app with more tunes as I haven't found anything Zen and copyright free.
#64 - John - 12/10/2011 - 11:23
I installed Fluid 2 but I can't change the screen. Do not get menu screen when I open this App?
#65 - Jeff Valore - 12/19/2011 - 13:38
I just bought Fluid 2 for my new iPhone 4S. Opened once and tried the coin flip. After that, it locked up and does not allow me back to any menu system, only close out through the home key on the iPhone. When I open back up the app, it goes back to that locked screen with the one coin in there. Help!!
#66 - Fabien Sanglard - 12/19/2011 - 13:57
@Jeff Valore

You can press 5 fingers on the screen to get the menu back.

#67 - Karie - 12/22/2011 - 03:47
I bought is App and I sent it to my cloud and it won't reload to my IPad now. It says it is already installed but it's not. Help stuck.
#68 - nicole - 01/07/2012 - 23:18
is this available for android?
#69 - Fabien Sanglard - 01/08/2012 - 07:00

The android version is currently being developed.

#70 - Matthew Ong - 01/16/2012 - 00:16
Hi Fabien,

I just installed Fluid on my iPad 2. Love it. Very soothing and calming to watch those rippling effects to zen music in the background. I didn't upgrade to fluid 2 because I am not much of toss coin in wishing well kinda guy. But I would gladly pay if u have an enhanced version that allows me to puck one of my own zen or new age or ambient music files from my music library. Also, is there a way to make the rippling effect to last longer? I have to keep rippling the water every 2 - 3 seconds; kinda defeats the purpose of just sitting back and let yourself relax and unwind into a glassy stare into those rippling water effects n the sound of background zen music.

#71 - Mary - 01/28/2012 - 16:42
I downloaded this but i cant make a wish
#72 - K'Shanti - 02/13/2012 - 11:28
There seems to be a bug. Multitasking causes the music to be disabled, and you have to close the app in order to start the music again. This happens across all iDevices.
#73 - Michelle Diss - 02/23/2012 - 12:50
I can not flip the coin for a wish. I've contacted you several times. Please respond. I paid for fluid 2. Thank you.
#74 - Fabien Sanglard - 02/23/2012 - 15:47

Your issue only came to my knowledge today and I will respond right away.

I think you are having trouble bringing the menu up, you need to press five fingers simultaneously on the screen to have this happen.
Once the menu is up you can select a type of coin a the bottom of the screen.

I hope this helps.

#75 - Maximilian - 03/12/2012 - 17:43
Your app was the first one I downloaded back then on my 3GS... Still have it now on my 4S (Fluid 2 actually..) And I just wanted to let you know that it's absolutely one of the best apps out there.. Simple and smooth. It works and it just looks so amazing.. Plus the background track is so perfect.. Thanks man!
#76 - Jack - 03/21/2012 - 18:28
You said you would post the source - while the snippet is deff useful, are you actually going to post the source or a public git repo for the project? Or was that just a tease.
#77 - Fabien Sanglard - 03/21/2012 - 19:59

For now the application is still generating some income. Even though I would absolutely love to share the code and knowledge I am cautious about some people that could just rip it with no respect for the original work.

I will release the source code at some point but I do not consider it an emergency since it is a very basic effect to implement for someone if they were to really try.
#78 - David Cunningham - 03/27/2012 - 02:21
Just bought Fluid2 for iPad 3, don't see anything allowing davidecunningham@me.com to select music - where is it?
#79 - Darrell Hampton - 03/31/2012 - 22:15
Love the app
This is prolly not realistic, but, it would make a great lock screen or live background
I have the ipad 2
Take care an
#80 - Valerio - 04/03/2012 - 10:25
Can you please put it in the screen saver. Tanks.
#81 - missy jayde - 04/15/2012 - 10:11
how do i make the coin flip into the water?
#82 - DLW - 04/25/2012 - 00:57
I had your first version of fluid for a few years and love it even then. I still love the new one and the fact that I can listen to my music on it. There is only one more thing that would make it GREAT! If it would scroll though my photos stored on my iPad. Thx for all your effort in continuing to make this program better.
#83 - Mary Lydon - 05/02/2012 - 21:25
The Emerging Learning Technologies team in Learning Technologies, Information & Technologies Branch, Department of Education, Training and Employment, Queensland provides advice for schools concerning their use of new technology in their learning programs. Currently they are developing Mobile Devices in Special Education: an advice for schools.

As part of this project they have listed your app for use with iPad. We are seeking permission to use a screenshot of the app icon


The icon will be used to provide identification. It accompanies the title and URL in the Mobile Devices document, which will be provided on this website: http://education.qld.gov.au/smartclassrooms/

We ask for your approval of our use of the icon.


#84 - John - 05/16/2012 - 14:00
lPlease port for Android!!!!
#85 - Tricha - 05/17/2012 - 20:53
I upgraded to fluid 2 but I still get that really irritating cover on fluid 1 asking me to upgrade.
Would appreciate if it could be removed from 1 once the apps
have been paid for.

I love your image, and want to keep it but thought I could now try one of my own - as well - now it's bought.
Thank you
#86 - Usman - 07/15/2012 - 20:17
I am a developer, and just curious did u use 2D effects for the simulation or implement some algorithm of fluid simulation ?
amazing work
#87 - Christian Genesis - 08/02/2012 - 22:33
Hello, wonderful app you've got here! A big fan and proud owner of the Fluid app! Anyways, would you please be able to tell me the name of the 'Zen' track music? It is very relaxing and peaceful, I would like to have it in my music library for special occasions in the future. So if you can, please, will you give me the name and artist of the default song? Please and thank you!
+ If you would please email it to my given email would be appreciated.
#88 - Samrat - 11/21/2012 - 12:54
It's something unique and good. By looking at the water ripples it relax my mind .
#89 - laurent - 12/11/2012 - 05:28
y want thi application in my comptuter its possible?
#90 - Panos - 12/13/2012 - 03:37
Hello, any news on the source code? Can we find it somewhere?
#91 - Bill Minton - 12/13/2012 - 16:39
This reminds me of a really old demo called TLWater I found back around 2000. I still have a copy of it if you'd like to see it. According to the readme it was written by Tomohide Kano.

Nice work!
#92 - Les Brown - 03/10/2013 - 14:41
My fluid 2 screen seems to be disjointed. I cannot make a wish as the movement at the bottom of the screen appears at the top, my coin does not move.
Help please
#93 - bemaat - 09/11/2013 - 16:59
Thanks though i found it was a but cuby so i changed the algorithm a bit and it looks quite nice.Though i havent implemented refraction or reflection yet.Just on a solid colour this is nice

#94 - SleperS - 09/19/2013 - 09:38
Hi, I'm from Russia. When will update?! it urgently needs!!!
#95 - W Kearney - 10/18/2013 - 14:26
Is There any way to set the time for how long the music plays?
#96 - Andy - 12/18/2013 - 13:30
Hi does fluid 2 work as a mirrored app on Apple TV!