Liquigen | The Era of Realtime Fluid Simulation

today is one of those special days where we are not doing a blender tutorial and the reason for that is liquid genen is out liquid gen Alpha if you don't know what that is uh neither do most people so you're in good company so uh you remember embergen that like software GPU accelerated that makes explosions fire smoke somehow in real time well same company called Jenga effects like the game Jenga um maybe spelled differently maybe not um has released a closed Alpha for liquen a liquid version of the same program it's closed in the sense that you can only access it if one you have the um the Indie Suite which is a bit more expensive than the embergen uh but once you have that if you join their Discord server which is where they are releasing it it's very strange that everybody operates on Discord now like mid Journey so uh you will get access to this Channel and I'm thinking let's do First Impressions and let's start it let's see what this is all about I assume it's very similar to emberg some kind of like node based thing andah they're saying it's not done okay great and and they're making me wait it seems like they're only giving me 14 days for liquid genen I don't know what that's about but either way uh let's start a new project and see so if I play okay there we go it's looking a little wonky for a second there but it seems like it is working and let's see if we can like move stuff dynamically yep okay it seems a little slower than Ember gen to be honest but that's still pretty impressive for a liquid simulation so I wonder if we can like down sample uh in the same way as usual so if I take the voxal size bring it up what I expect is the bigger the voxal size yeah the faster the simulation that's really nice okay so one thing I'm noticing is that there's this new sphere object which I don't think represents the domain but more so represents where the um I don't I don't think it's called outflow it's where the um simulation kind of stops like it drains it outward so if I do this it will uh only simulate to the right and to the left okay I'm liking what I'm seeing that's pretty impressive okay so uh let's play with some stuff I'm going to change the Primitive from a cube to let's say we are going to emit from a cylinder increase the height increase the radi and okay so that seems to have been what is up so uh okay clearly it works but the main thing I'm interested in is what do we have control over specifically uh do we have control over viscosity that's what matters the most so uh in simulation what do we have access to we have like normal settings I assume stickiness is is the same thing as um what I was just saying yeah now it's looking like honey what was the word wasn't vortis it was called um not adhesion either I I literally just said it viscosity there we go okay so that's actually great news because those are the more interesting simulations in my mind kind of like these honey uh type of simulations okay so can I get kind of like a nice glazing it still kind of looks like goop uh but I think that is a function of me not picking correct settings okay what else can we play with so ickiness that's great um okay so it seems like the way this works under the hood is it first of all just runs kind of like a particle simulation and then it skins it it turns it into a mesh uh which is kind of like this second parameter so I'm not going to play with that yet do these have a hints okay how much the density affects the Divergence higher values should enforce incompressibility so if I lower this it's almost like this liquid can intersect itself which should give kind of different looking results okay so we got our honey uh let's make this more interesting so for our emitter um okay we have our volume flow rate so now we got you know the Nickelodeon slime Festival uh let's bring that down significantly so we're not creating as much it is time for you to take your skills to the next level with skillshare skillshare is a 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just watch those now immediately so back to the tutorial thank you skillshare for sponsoring okay so here you can see what's probably happening under the hood it's basically simulating a lot of particles that then get meshed probably using one of these Delani triangulation algorithms okay love to see it uh what else do we have control over so uh what about the drain so drain seems pretty boring okay great uh let's play with some uh forces so for the force by the way I'm just right clicking it seems very similar to a embergen uh let's see what kind of forces do we have turbulence turbulence so I'm going to apply this here and what I'm hoping is this is going to add some like Randomness to our simulation especially if I increase the amplitude yeah now it's looking more bubbly uh bring down the frequency to make that like lower um kind of like more not as bumpy detail okay yeah I would not recommend using this that looks pretty lame okay what else do we got we got Force we got drag which I imagine will make it kind of like slower like it's fighting the air so let's just retry that little hard to tell let me bring up the power what I'm curious about is can we get a material that kind of looks like honey one thing that I just found that is interesting is in this render we have access to path tracing so this is without it's kind of what we've been doing but then with path tracing I guess this is where we get our watery looking things now one thing you're going to notice is it seems like it still seems like it's real time but in some sense it seems actually slower is that the case yeah it's definitely playing back slower which I guess makes sense um what else can we control here I guess we can basically just kind of control like render settings in some sense so uh clearly it's trying to do a fast pass at a ray tracing or path tracing uh and then it's running a very strong D noiser but uh I would imagine when we're getting to the export and we'll try rendering this in a second uh we can get more control again I really want to know can I get control of the material settings so kind of the irony here is it seems like all this time it actually was accessible but I just had to scroll down a little so um I don't want to to do path tracing anymore let's operate faster um in this appearance node this seems to be where we're going to make it look like honey so for the alido I'm going to choose kind of like a yellowish color uh yeah yeah reflective whatever uh this is also going to be kind of like a golden orange and I guess to kind of see what this looks like in practice let's run path Tracer okay so now we're getting closer to honey it still looks way too liquidy so let's see transmission strength clearly that's not the one index of refraction it seems like these are pretty standard settings it would be kind of the same settings I'd be used to in a blunder so it seems like the roughness is going to make it less like heavily reflective turns out we can have metallic material and can I just just increase the brightness okay okay now we're getting closer to honey so let's just kind of try to pick nice values okay and I think it's probably about time to try to run a kind of like a render here so it seems like uh when you're not ready to render uh disable path tracing it'd be nice and maybe there is a hot key for this uh so I don't need to like enable and disable so I'm thinking let's make kind of like this uh honey simulation where uh we can just kind of increase or optimize our settings so for the emitter I want there to be way less fluid uh so that it's kind of like a more constant stream and we're trying to make this look less like uh goop so for the emitter which I guess right now is a cylinder I'm going to turn that into a sphere that sphere is going to be smaller I'm hoping that this is going to make a more pleasant looking stream actually ew um let's see what else we can do I know I'm just playing back and forth with these but that is kind of the point isn't it so I think the main limiting thing that's making me feel like it's not honey is it seems like it's falling quite quickly it should be really viscous even as it's coming down but I guess it is subject uh to the same force of gravity so let's see what we can do okay so this is the force that represents gravity I know this because it's 0 9.8 if you take in physics this means gravity go downwards so if I was can I just write divide by two I can uh this will make it slower again is it physically accurate no uh but I like the way it looks okay oh by the way step rate seems to be quite important this isn't just kind of like the FPS of how it's simulating uh but it actually kind of changes the behavior so if I was to bring this to 15 right it doesn't just make it four times slower but now it's kind of like behaving differently than if I made this 120 but I believe the higher this number is the less kind of like effect we get but this kind of looks more like honey honestly uh the more IP I see the less viscosity but the more unstable the flu no no no no bring that down bring that down that's the exact opposite of what I want yes yes this seems to be it so this seems to be more of the way to get honey kind of style simulations or maybe you're kind of pouring a chocolate over something and it seems like again there's kind of two passes of this there's first of all there's first of all the particle pass that is then triangulated right uh so you know if I'm happy with my simulation but I don't like the meshing right it seems like I can just change this after the fact which is kind of cool cuz it's kind of two separate operations so I'm going to maximize the smoothing this is because honey is kind of like this goopy not really you know uh bumpy looking thing generate SDF on smoothing interesting uh by the way SDF means s distance function I believe which tells you the distance from the surface I don't really care about that uh what is ISO value the surface of the liquid okay so ISO value is basically saying how close are we skinning it to the point Cloud so the smaller it is it should start breaking yeah so you can see what's going on over here so let's disable points so you can see how it kind of gets weird I would probably increase this quite a bit uh to get more of the honey looking look again hopefully there is a hotkey is there I do not know if there's a hotkey but this is our secret uh for making it look like honey so what else can I ch change still looking a little weird make it brighter make it more golden okay there we go that seems to actually be the one we'll figure it out now by the way if we get to the point where we can export this I guess not as a VDB sequence but maybe as an almic or something like that um then maybe we could just kind of do our materials and something like blender and then this wouldn't uh matter anyhow oh we can export a map that's actually quite interesting so we'll try that in a second I'm going to save my file okay so they're actually let's actually check some of these out um orange goo waterfall cuz it seems like there are much more you know there there's more you can do than just honey but it is cool I guess to see projectile bubble that did not open oh there it is okay so this is where it becomes a closed Alpha okay uh it seems like of course the higher resolution uh the simulation is the more you know you're going to get uh let us kind of finish up the simulation so instead of a Taurus uh let's say that we're kind of I don't know we're kind of glazing honey on like a chocolate bar or something so I'm going to do a capsule I'm going to make that a bigger capsule with more height and then just rotate it so it's on its side again making this bigger and wider so to actually key frame the position I believe all we need to do is we need to key frame the position and then I wonder if it actually writes dynamically I don't think it does so I think we we need to explicitly write key frame so uh for the position let's say right here we add a key frame and I guess we do this to all of these we go some frames down now it goes sideways adds another key frame so it's going to kind of look like that and then it will I'm sure there is a way to do this better and it probably is similar to how you do it in Ember genen I would say comment below but I have comments disabled so let's see what this looks like honey honey honey let's try just doing a render so I'm going to render this as a sequence not a flip book but a sequence which is going to give us you know a bunch of images in a row instead of putting them all on one Sprite sheet I'll this at 512x 512 um and let's say that we do it for 300 frames uh which goes from okay clearly we need more frames so here you can see the kind of the length of the project over here uh so I'm just going to make a folder I'm going to call it liquid render and then finally let's just make sure we have path tracing on fine I'm just going to pick our directional light and bring up the intensity okay looking looking weird but then that that's fine um if anything it kind of represents our honey kind of colors going on finally for our actual export right so now we're just rendering I don't care how long this takes uh I'm going to now kind of decrease the voxal size is kind of like a kind of like a final kind of bum in uh resolution okay let's try it so export image and I don't know what else to there is to do export by the way we're getting a black background why why why I oh here we go so there's a difference between render viewport and render all so that means I can just pick render viewport in theory okay export now okay great so is it 7 Minutes yes but is that still impressive for a liquid simulation by the way uh normally the way you see a liquid simulation is as like maybe a multi-hour simulation that then you have to tweak and say oh that wasn't right now I got to render or simulate again and simulate again and rendering um I guess kind of depends on your scene so I'm going to let this run for a minute and then we'll come back and see what it looks like and then of course we'll also um try to export this as a almic or whatever and bring it into blender okay so this is still rendering and I'm getting impatient again faster than a normal thing but with progress comes a new versions of uh impatience I want to see what this image sequence looks like at speed so uh I'm using blender as my video editor of choice so video editing add image sequence I wonder if it kind of comes in at 120 FPS which is fine but let's find out okay so clearly it's playing slowly what if I made a 120 K that's faster or I can make a 30 FPS go to is there some kind of like speed setting okay apparently there's a set speed command so 100 is normal so let's try 400 and that would hopefully play at you know what we consider real time okay not bad it's very noisy but that's kind of a result of the render settings that I picked but overall not bad clearly it works okay so now the question is that looks you know it looks fine doesn't look great uh can I bring this into blunder uh to do my own render let's find out so uh here I've have an export mesh node and here we have the mesh it seems like we can also if we wanted to uh export the particles and use them for a different purpose maybe running them through a Geon noes or something uh but I'm going to export mesh inside of liquid genen well not inside of liquid gen inside my directory that takes forever to load I got to figure out what that's about uh inside my liquid render I'm going to add a mesh folder okay so it turns out maybe what we want is a almic do I enable is sequence set to truth cache is split into separate files no import almic and where is our limic is it tiny enable sequence okay so you have to enable sequence great so now okay cool uh so it seems to be playing at 120 frames per second uh which is not what we want so let's see if we can modify that so seems like you might want to export at your frame rate in some sense I don't know if that's an option uh but we can probably kind of trick this thing so we can overwrite the frame this lets us actually just pick where we are and then could I so if I write hash frame which gives us the frame number it's going to give us the exactly same issue but now that we're at 13 frames per second to get from 120 to 30 you divide by 4 do you see what I'm saying I'm saying we're going to view this four times slower so you know you could export at the right settings but this seems fine to me now one thing that's interesting to me is does this kind of preserve things like a motion blur okay so EV motion blur by the way acts different than um than uh Cycles motion blur where it basically just takes all the frames and just kind of Blends them together so maybe I mean clearly this is an option but maybe you know it's kind of a cheat I want to see if this actually works in Cycles to inherit motion blur which I don't think is a liquid gen issue I think it's a kind of a result of a lmic and maybe there is a way around it yeah so if you could export certain attributes like the velocity attribute uh which may or may not exist it seems like it does exist exist then maybe we could kind of do it in compositing let's find out so I'm going to give this a material the reason for this is I want to access the attributes and I wonder if I go into Geon noes it might tell me the situation here so here we have our points it seems to only inherit the position so maybe it doesn't actually have a velocities attribute well let's find out I'm going to copy this I'm going to paste it and okay that is empty and I believe at the moment we do yeah we do not have options to export uh certain passes so I would love of course um to have a velocity pass since it seems like a lot of the stuff kind of depends on it but we do seem to have things like normal passes okay that's good maybe I'll bump it up to 12 get the cleanest motion blur okay so there is a version of this that works uh hopefully the idea of rendering inside Cycles instead of inside liquid gen is we get controls like modifying the material increase transmission okay we're getting somewhere um I believe the roughness okay that seems to matter one thing I'm noticing is we're kind of getting strange shading but if I bring this up just a little that seems to hide whatever is wrong and that that actually looks much cooler you can see the honey distorting it uh if you wanted to it would kind of be a bit of a sheet I don't know if it would look good but we can map a three-dimensional noise texture which you can see Works based on generated coordinates I wonder could liquid gen make advected UVS I'm asking for aded UVS if a jeno FX is listening that would be huge what that means is we could actually have a noise texture that maps to the fluid as it flows instead of kind of like you'll see this um it kind of just exists you can kind of get away with it but I'm asking for advected UVS that's a uh thing that you could actually create with Houdini so here is an additional normal map I'm making yeah so that that's just going to add some visual interest so this is without this is with say what you will or can we import have I spoken too soon no we we can import okay so it seems like you can take like a suzan and then import it and then run it through as a geometry that I guess you can use as in theid okay so that that works maybe I'll do something with that but this is basically my first impression of using it blind thank you for watching uh if you want to get the thing you know get it uh okay cool

Channel: Default Cube

Views: 58,840

Keywords: liquigen, fluid simulation, realtime, water, simulation, embergen, jangafx

Id: 0AkbQHYF-dU

Length: 24min 13sec (1453 seconds)

Published: Wed Feb 14 2024