HOUDINI 20 - Flip/Whitewater Sop Level Course [PART 1]

let's jump into the world of fast and easy flip simulations with hes2 latest update with this new tutorial series all right so we are going to try out the new flip solver on the SOP level since the flip solver and the flip simulations have come to the SOP level I think this is the future because almost everything that you have on the SOP level you are not really going to get them on the dop level I don't think that will happen you know ever so uh you know if you like it or not that is the way ahead we'll have to adopt to these uh sof level tools which again you know they are like really good so we are just going to make lots of tutorials and lots of series telling about all the new tools okay all right so let's just start so let's get our Collision geometry which is going to be the crack over here and here just walking by over here and I'll just make a container in which we are going to have the water so let's create a box and you know this is same as like creating a flip container which we used to do previously on the dop level now you know it's all on the SOP level and there are different ways to create this container however you know I'm just going to use this one okay so I'll just create a kind of a box over here which will represent the domain size or you can say you know the ocean size or the flat tank size whatever you want to call it let's increase the size of this box maybe let's keep it over here and yeah that is it okay all right now the next thing is I want to create this I want to convert this box into the lip domain so I just do a right click and now one really cool thing is you know this UI is like very neat all of the options have gone inside to the respective folders so you can just go into this Dynamics flip and we can just add a flip container let's add the flip container let's connect this and this is just setting up the container over here now we have the particle separation we can again control the particle separation grd scale everything that we had on the flip object so this flip container can also be known as flip object okay and the next thing is like flip Collide okay so either you can type flip Collide or you can just go to the again Dynamics flip and just get the flip Collide over here bring it close to your flip container and it's going to automatically connect everything okay okay now you can just connect the uh Collision source to this thing and that is it your collisions are ready so how cool it is how fast it is now we just need to work on our artistic skills next 5 to 10 years almost every artist needs to be very fast you you know so just work with the tools which are provided and you know get the best output and that is all okay all right so we have the flip Collide over here and the next thing that we want here is the flip solver let's connect the flip solver over here and our simulation is not ready yet obviously so the first thing that we want to do is you know like uh right now we have the flip container we have the flip solver but we don't have any V so either we can get the water through external Source or because right now we are going to create a flat tank what we need to do is you know we just need to go into this water line option and just click on this water line and that itself will just you know create a flat tank for you and the domain size will be coming from this box which is going into the flip uh you know container all right so I don't know like for what reasons they have you know made this big spheres by default I just don't like it just go to the visualization and just uncheck this point as spheres and what you can do is you know you can also just do a right click and change it to the uh make current value default so you don't see those big ugly okay all right so anywayss let's just go back to the water line and uh the water line is set to zero so this water line is again you know the water level uh which we had in the ocean source so I'll just change it to like maybe something like 35 and so on and yeah so that is you know that will just cover the legs of my crack and maybe I can you know just change it to like 0.4 or okay I'll just go to the uh maybe left view or the right view or something and let's just uh you know check the size of our box so once again I'll just make sure that my box is like you know um like big enough so that you know the feets uh I mean once again you know don't have to be like very perfect you can just you know make sure that you know your feet of your like any Collision object that does not intersects with your bottom floor otherwise you know it it starts to create some issues and something like this is like completely fine okay now that is done now there are few things which I would like to tell you so first thing is like you know the particle separation so if you decrease the particle separation you know you will have more particles and your simulation is going to look you know like much better obviously so decreasingly particle separation will just give us you know more particles also you can press D go to the geometry and change the point to the pixels okay all right so now if you look at the flip container from here we can change the particle separation which will you know control the overall resolution of our flute simulation so what I really like to do is you know like uh I don't really want to go back to the flip container again and again I can literally you know like just have this same control in my flip solver and I don't have to go back and forth over the flip container so what I'll do you know I'll just uh click on the flip solver click on this button so just click on this edit parameter interface and just you know like we have this root option which has all the options inside this and you can see like we have this start frame over here and just below this start frame I'll just drop drag and drop this uh float value okay and after this I'm just going to call it like maybe PS so you know like this is going to like uh control the particle separation overall so I can just click on this apply and accept and what I'll do I'll just do a right click copy parameter go to the flip container and just do a paste relative references so now this way all the resolution related stuff will can be controlled directly from the particle separation over here okay the node over here the option over there okay so by default not all the options are uh not all the options work very well with the flip sop level so there are a few things you need to change so the first one is like you know the how the collisions are behaving so right now you can see like you know that is what we having and when this object goes into the flip Collide it outputs a VDB as well so if you just add a null and if you try to see you know that is what we have now you can also see we have collisions as well sorry I mean we have surface as well you can see you know this area so basically it's out putting a surface and it's also outputting um you know VDB so we don't really need that so just make sure you turn off this surface Collide I've seen like you know it tends to create some issues so you can uh leave it off if it works fine for you but you know I'm just going to turn it off okay so that is the first thing second thing is uh go to your flip solver and just make sure uh I've seen a lot of students making this mistake they turn on this particle separation and they think this is the actual resolution but that is not so this particle separation is like you know it can separate the particles in order to like prevent volume loss or other kind of things especially when you're doing some small scale simulations and stuff so you don't really need to you know uh touch the settings so you know you can get confused easily like you know this is particle separation which is also this and which is also this but that is not the particle separation which from where you want to control the resolution so please avoid that now the second uh not the second I think the third thing is you know like uh go to the like uh Collision go to the surface extrapolation change it to like 0.1 and you know this way we will have more splashier kind of uh splashes okay fourth go to the fluid Behavior change from apic to the flip you know I think maybe uh they had in mind to like tackle the small scale simulations on the SOP level that is why this is set to the default to the apic apic is much better for small scale kind of simulation we don't we are not really going to do any small scale solution so that is why we're just changing it to the flip okay it's really good now we have option options like detect droplets also on the sof level which is like very important this is like one of the main part of the larger scale simulations and this is here which makes everything lot easy otherwise you know we'll have to go back and forth inside the doop net and change stuff now if you're using hood2 by default your solve pressure with adaptivity is turned off and your use multigrid precond conditioner for pressure uh calculation is like you know kind of on so this makes things faster however I've seen like turning this on you know like creates kind of issu so I mean this is kind of outdated in this newer version so make sure you're using hne2 or if you're using uh any version between before H20 just make sure this is off you know I just don't really like this one okay all right so I think that is done and we can start with the simulation however you know like this is going to be like really slow on the viewport if I you know like if I just play it back let me show you okay so you can see like even though the simulation is cashed out but still you know like this is kind of laggy in the viewport the reason for that is you know because it's displaying this Collision and stuff so just go to the visualization and just turn off the show Collision okay again that won't make everything too fast so what I like to do is you know I just add a merge note and I'm just going to look at the output of the flip particles from the flip solver and I'm just going to look at the Collision from the main node and now if you see you know this is going to be like much smooth and you know I think we can start with our first simulation okay so before starting with the first elimation I'll just change a few things I'll go to the flip Collide for the velocity scale I'll increase it to the three okay and uh I think I'll just go to the flip solver and for the particle separation I'll change it to like 01 okay and I'll just change the color over here to make it like you know kind of more dark that way you know like we can see what's happening and you know like uh I just copy this color code paste the same over here and just try to make it more white and I'll just decrease the max speed so this way you know all the particles which are going to move faster they will you know uh have a more white color which will be like you know um like we'll be easily able to understand how the water is moving and the behavior of water all right so let's just look at this let's wait for the Sim to happen and let's see what we get okay so we can see that is what we have got and I think the simulation is looking good and the best part is you know we don't even have to set up the volume Limits The Boundary layer the water line nothing and you can see like the new boundary layer and the water line features are like so improved all the water it goes to the it gets absorbed there's like literally no uh reflection of the Waves there's like no you know like uh problems in the boundary and and you know like I think that just looks great because uh we don't have to spend any time on that and you know like that was a part of a technical issue you know which we used to face which has nothing to do with the with our artistic skills and that is what I'm trying to say you know like the world is moving more towards the artistic side and the technical problem they are being getting solved by the you know like all these things if you see our animation is like kind of same throughout uh the frames you know like from here till here okay so but if you go into the if you look at the last part where he flips his hammer and you know BS it on the floor that is where the animation is changing and I really want to see this part how this part is going to look okay so for that what I'm going to do I'll just take this box and I'll just change the position of this box to like you know so it goes over here and now I can like only focus on this part without worrying about what's happening previously because I've already fixed that out I think that is where I just want to look you know how the simulation is going to kind of look and like whenever I'm doing any kind of simulation uh be it pyro be it Flip or any simulation I will always try to have as small uh simulation box as possible I just want to see the main effect the main area where the action is happening and once I'm done with that area once uh that area is looking good I can just you know increase the uh container size and this is something which I tell every want to like do because uh you know it makes your simulation faster and you know like you have more iterations in less amount of time also in new flip solver we have options to like increase the resolution of a particular area which we are going to see in upcoming tutorials all right so I think that is what we have got and if we click on this flip container go to the flip Collide everything is working out the only problem is if I click on this button it's going to start to simulate everything from the first time and I don't want I don't really want that what I want to do is you know I just want to see like this part uh first like you know from 228 to like 240 uh in this part let's see uh so I think we can simulate from frame 242 okay so just go to your flip solver and change the start frame to like 242 and you don't really need to care about all the previous frames okay so one more very important thing you know like when we are doing this kind of simulation is you need to see at what frame the hammer is hitting and like you know let me show you what I mean so if I just go to the uh kind of left view so if you see we have like three four frames for the animation of the hammer so it starts from here it goes here this is the movement when it hits the water and at this moment it just stops so we have to make sure okay so I'll just change the start frame to 244 as of now and we just have to make sure that the hammer is hitting the water so make sure your water level is you know like big enough to compensate with the area where the water like where the hammer is going to collide so if our water line was set to something like you know maybe like 3 it won't work you know because there's no collision with the hammer and the water and literally in the next frame the hammer there won't be any velocity with the hammer so just make sure you have the right value over here okay or at the same time you can also you know like uh just change the position of your crack you can make it you know go a little a little bit lower but I think that is fine and now it will be able to make the splash but as I said if you put the value to something like 0.3 or something there's no Collision here and in the next frame the hammer is just going to work still so just make sure of this thing I've been through this thing a lot and the reason actually the reason why I know all these things is because I've done these simulations like kind of million times maybe less so yeah all right so I think uh that is it let's make a review all right so if we look at the same that is what we have got and you know like we have got some blasting particles and obviously that is like way too much so what we can do is you know we can just use a pop speed limit to control these shooting particles okay all right so what I'm going to do I'm just going to go dive inside the flip solver over here you don't need to like you know um like click on this allow Ting of contents and all just go inside here and we have this Force option just use a pop speed limit and maybe I'll just set it to like maybe five five or so and let's make a preview again and you know that is uh how important it is to like make a small box because if I try to make a preview of the whole thing it will just take another 1 hour and you know uh like that will be like very long so let's just make this preview and see what we are getting and we will just continue from there on okay so if you look at this that is what we have got and what I feel is like you know maybe the splash area could be little bit uh smaller all right so let's do that once again uh so what I'm going to do you know I'm just decrease the pop speed limit to a smaller value to like I'll change it to four and let's just have a preview again and let's see what do we get now okay so by the looks of it I think we have got what we were looking for and I mean the splash is not uncontrolled and you know it's good enough the size is not too big not too small that's what she said all right so yeah I think that is good enough and let's just look for the middle part okay let's just look at the simulation of this area where the CAG is like you know uh making his you know like Hammer standup all right so what I'll do I'll just change the Box position to fit this area now so it starts from here and I think you know we can just keep it somewhere over here uh yeah all right so let's start it from I think frame 180 so let's change it to 180 and you know like that is how we get any kind of simulation like in a much quicker way by just simulating small Snippets of it and then you know combining everything together all right so let's just make a preview and let's see what we get all right so I think that looks fine and now we can just you know simulate the whole box without worrying about you know like if something goes wrong in middle or something all right so let's just click on the main geometry and let's look at the container and I'll be making a pretty huge container so that it can have you know all the proper motion of the water so let's just move this container here and this is the start point this is the end point and I also increase the size from the sides as well something like this okay so for the final resolution I'm going to like go for somewhere like maybe 07 not 07 sorry 07 and the start frame can be the frame one okay and now after this we just need to have a flute compress node as well well again in order to like compress the size of the cache and you don't like you know like don't really need to connect everything I mean the first one is fine but you can just do it doesn't really matter okay so in the fluid compress I don't think you need to change anything because by default you know like it will just take the original data from here and I mean don't really need to do anything at all all right so let's just save it out so I'll just add a file cach and not defile node sorry defile gache and I'm kind of old school so I'm just going to stick to the explicit version click on this go to the desktop and I'll just make a new folder and I call it crack Sim go inside this make a new folder let's call it particles and let's just write anything I won't write anything I'll just say dollar if. BG eo. so it's just going to save everything in the format of bj. and I think yeah I'll just save everything to the disk next part we'll be looking at uh meshing the simulation so we'll see how to match the simulation in the most efficient way and we'll also set up the shaders and the renders and everything in the Kaa we'll also use kerma xpu and the karmma CPU all together and then we are going to use the whitew solver on the soop level and you know we just Stander out the white water as well all right so just take through the videos and you might have all the knowled which is required for the latest Hy tools which came out in 20 version okay see you in the next tutorial bye-bye

Channel: INDIAN VFX SCHOOL

Views: 14,079

Keywords: HOUDINI20, FLIP, WHITEWATER, VFX, FX

Id: ZsPBU8KKqTY

Length: 19min 36sec (1176 seconds)

Published: Thu Nov 09 2023