Hi! Great results! Really nice. Regarding the looping part in Houdini: you could convert the *mesh version* of the fluid sim to vdb, and then loop it. Then after that you can convert it back to mesh. I used this trick a few times, sometimes with a blend node using the grid option, sometimes with the "make loop". I find that this way gives me more control over the looping options
you should check out "How Disney's 'Moana' created its amazing water effects" on youtube. it has the best physics of water and the most likely to be re-created in a video game. I hope they eventually sell or license the technology to unreal. It would be a game changer
I've played with Niagara Fluids a little bit and in my experience you can go much higher quality with a pre cached sim, however i think Niagara Fluids are the future being able to be simed Realtime is a whole different ballgame, once the tech matures
Looks fantastic, great job! There is a another way to loop it although it requires more setup. Sim your particle/fluid cache, lets say its 100 frames. Then copy/paste the cache and offset it the amount of frames in your sim. (100) That way a new instance of the sim starts on the same frame that the previous one stops. Then mesh both instances of the particle/fluid sim together. Should get you a clean loop. You could also use vertex colors to blend in a foam map if you wanted a bit more variation in the texture.
Very nice. Although the OCD in my can't ignore the ant "pulsing?" up and down the whole time. I don't think ants really do that. It's really distracting
Awesome video. Thanks a lot. I have trouble with getting Motion Blur at all. I use Maya for creating the Alembic file and it has motion vector information in it. Is there a specific thing I have to consider? Of cause I check the right import option in Unreal but maybe is there something wrong with the vertex color set.
Hey, One quick question. So I have been using this method ever since I saw your workflow. I think its genius! I have three viscus fluid sims imported into my UE5.1 scene and I have the same settings for my material, but each mesh cannot be in focus unless it is intersecting with geometry behind it that is in focus a.k.a. I can't render it with DOF without something behind the fluid cache. Any ideas on how I might approach fixing this or maybe a setting I'm forgetting?
So I found this is only a problem when you want to use glass that is default lit. DOF works when its set to thin translucent shading. I would love to learn/understand better why that is not the case with the default lit tho.
In the material you will need to make sure its set to render before DOF and tick the output velocity checkbox which also makes it write to the depth pass, then it should work
@@dylser Thats actually why I'm confused. Even with that done, if the material is default shaded translucent its showing out of focus unless I pull the focus plane past 5000. This has happened twice today. I had some alembics that had this problem but so did an FBX. I just can't figure out why it won't. I was able to tweak my thin translucent to look really good like normal glass, but would love to figure the other one out. I bet its some checkbox that I accidentally clicked somewhere in the material.
It looks stunning! My bachelor thesis which I finished just a few weeks ago was about comparing FLIP sims in unreal (Niagara Fluids) and Houdini - now this looks like a cool hybrid , to sim in Houdini and render in unreal, love it 😍
Looks awesome! A few years ago in UE4 I tried using alembic caches generated using FlipFluids in Blender and it destroyed the framerate during runtime. I ended up making a blueprint to show/hide each mesh for every frame that I could then control the framerate. It would play back similar to a cartoon flipbook animation lol. Good to see UE5 handling the caches well!
if someone still have issues with loop, cache the vellum fluid (this issue is only with vellum), create a point wrangle, add ID, (ptnum) Life ( 1), Age(100), then use make loop. nice loop
Very cool - I just started learning Houdini basics during the megajam, so as a jr. this all seems intriguing but complex at the same time. Any suggested learning paths for a n00b that would love to get to this level of understanding? How long have you been working with Houdini? Thanks for sharing, it's greatly appreciated. Ha.. just realized you sort of address not being an Houdini guy at the end of the vid - I'm going to leave the question anyways as I think its still valid ;)
haha yeh I am most definitley not a Houdini guy, but I find experimentation and youtube tutorial to be the most useful, but i suppose We have been using it quite a bit at work recently so I've been learning from our one Houdini guy haha
Thanks for making this, is there a way to deal with fluid sims that have more surface area? for example a melting sim? Would that be pushing the boundaries of the ABC to unreal workflow?
haha I suppose I could do a lower quality asset pack in the future, these sims are usually specific to the geo in the level though so they wouldn't fit with other places, its really more of a bespoke simulation per area.
If you don't mind me asking, what system hardware are you using to simulate such nice high-quality fluid in Houdini? Awesome stuff, thanks for sharing!
@@dylser Awesome! I’m building a TR Pro workstation too. Currently debating between the 32C or 64C part. Do you think the 64C would make a big difference for Houdini Sims and UE5 source and shader compiles? Thx!
@@kyozon8925 Well it certainly will make a difference for most Houdini stuff, just watch out for certain processes in Houdini that are single threaded which catch me off guard sometimes, but FLIP sims definitley are multi threaded! and yeh the 32C absolutley demolishes the UE5 source compiles haha so i guess the 64 would be even better
Hey thank you for the video! Trying to make water look the same as yours, copied your material, but still it looks cell and fake. Any tips ? Anything has to do with lighting or environment tricks ?
Is it the reflections what look strange? I'm using the "High Quality Translucent Lumen Reflections" setting in the UE5-Main branch on github which does add a lot for translucent materials.
This is freakin awesome Dylan. May I ask what settings you used on the nodes of the optimised alembic file in Houdini? currently doing my own sim and getting huge file sizes cheers
Cheers! yeh sure the remesh I did for the optimised mesh for the really nice looking one in the second half of the video was to set to adaptive, relative density to 1, Gradation to 1 and min size to 0.05 , which brought the poly count from ~1 million down to ~300,000 , this was a change of 15GB alembic down to 3.3GB and then around 600mb when imported into unreal
Not to take away from your work here, because it is fantastic - but this approach would not be suitable for an actual game would it, given the huge amount of disk space required and surely a fairly significant amount of processing to run?
Disk space once imported is quite reasonable for what you are getting, these caches are 300 to 600mb once imported, and processing depends on Disk speed and the resolution of the mesh, when optimised has been fine for higher end machines, in fact I imported a 90GB alembic into Unreal the other day and even that played back smoothly in real time, it's definitely doable just within a certain scope. Ant ausventure runs at 30-50fps at 1080p on a 3080 with two of these caches in the scene, so I can imagine as more optimisations happen it becomes a bit easier
Hi! nice Sim. I tried with simulations in alembic and UE5, but I had problems finding a workaround to bigger files and found no script to read single frames in sequence like in other programs. I would apreciate if u had suggestions. Thanx
hey, so its a 100 frames loop? im always very demotivated by the huge sizes of alembic or vdb files :((( but i heard there is a new AI compression to vdb drastically reducing the file sizes, which is great great news to me
Yeh I've done 100 and 200 frame loops, when optimised with a remesh and culling unneeded geometry they get down to around 1-6gb most of the time , depending on the size of the sim of course but once imported to unreal they get compressed quite a bit, most are around 300-500mb on disk once imported
Any pipeline to import a decent number of particles yet? Say over 1 mil splash or foam particles? Im not concerned of real-time, just if there's a way to grab all the points and attributes from Houdini and not have anything crash.
Great work! I had success to import Liquid sim from PhoenixFD to unreal but had to chance to import the foam, splash and mist. Is that possible to import those into unreal?
I cannot believe this is being run in real-time-ish! We have NEEEEVER been able to have water physics this real looking in video games! It's so exciting to me!!! I assume this is not interactable water and it's just a sort of real-time simulation correct? Do you think in the near future we should be able to get to the point where it's interactable and dynamic with changes to the environment? Nevertheless it's a HUGE step forward in video game graphic simulation... even just running through a scene like this in a game where you can't jump in the water but can atleast look at it up close adds so much to the ambience and realism of the game's world... LOVE it!!! Excellent job! Thank you for sharing!!
So this is not a realtime simulation, you are essentually simulating it offline in Houdini then imported an animated static mesh into Unreal so yeh not interactable aha cheers!
For what you're after, you would be interested in Fluid Flux and Ninja Fluids for real-time simulations. Not exactly FLIP fluids but they're still very realistic and impressive. This alembic is a baked animation, it looks beautiful but takes up an entire hard drive of space and kills performance so only good for cinematic renders I guess.
Amazing stuff Dylan! I was wondering where I could find info regarding a way to also include foam or splashes in UE5...do you think that would be possible via Alembic Caches? Or is that something that would be sorted out withing the water material in UE?
Foam there are a few ways, I did a new video showing a baked vertex colour workflow here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZfmLXfWKJ0c.html for splashes, probably easiest way would be to use Houdini Engine to import particles form houdini maybe?
Splashes work fine as part of the sim, and foam / bubbles can be done a few ways , I did ti with vertex colour ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZfmLXfWKJ0c.html
@@dylser i heard on a podcast from epic developers that unreal has a 2.1 gig alembic limit. is this not accurate? i have 128 gigs of ram and can never go past 2-2.1 gigs.
@@halfMTstudios Interesting, I have definitely imported 12-18GB ones recently, it just takes a while, and the one in shown in the second half of the video is over 3GB
@@dylser but this vertex animation issue will be solved in 5.1 ? Its a Lumen problem or even in raytracing mode ? Thanks for your time 👍.really inspiring.
@@antoniopepe I'm just not sure it would accurately bounce light using software Lumen thats all, will have to give it a go at some point! should be fine in hardware lumen mode as that uses RT
I tried to import beach waves alembic cache 40 GB simulated in Houdini, which is working well, but the problem is still the import of whitewater... It's almost unable to import such a big files of particles to niagara.. and vdb not working at all... I would appreciate some particle caches import directly into sequencer or something like that...
Have you tried creating a mesh from them? You could convert them to VDB and then back to polygons and then use the same method from this video I would think
