[Houdini Tutorial] Melting a Chocolate Bunny

hey guys hope your day is going well today I wanted to show you how to melt an object in Houdini as I'm recording this we're just a couple days away from Easter so I think it'd be fun to melt a chocolate bunny you can melt whatever object you want and I'll show you how to start let's make a new project just called this one chocolate bunny tutorial and let's save it okay now let's go ahead and create our object like I said before I'll be melting a chocolate bunny so let me drop down a geo node here bunny and similar to what we did with the coin imprint from one of my previous tutorials let's drop down and an image of the thing that we'd like to create so I'll drop down a grid make it two by two drop down a UV quick shade get my image on there alright and let's change the perspective view to top I'm just going to drop down a transform node real quick and rotate this alright and now that we have that let's drop down our curve and you have to make sure that your handle is on this guy right here in order to do it now just like the coin the more points that you have the smoother your object will look so just kind of take your time and don't forget to press ENTER let's change the view back to our perspective and here you can select any points just kind of edit them or you'd like make sure everything's good and let's drop down a poly extrude don't forget to output the back and make it as thick as you want your object to be I think I'm going to make an eye on the bunny to give it a just a little more detail so to do that I'm going to drop down a sphere let's make it probably gone mash just like a really fine just so you know you have the blue flag which is the display render flag but you can also do a little template so you can get a nice wireframe of a different note so then you can compare so I'm just going to drop down a template on the sphere and model it to the shape of this eye all right let's see what it looks like with the bunny and I'm going to drop down a merge node and that just combines your two geometries and that way you can see them both together and we have our basic bunny shape with an eye I'm going to transform it so it's standing up and let's change their perspective or front and just make sure that it's right there on the ground okay all right so we have our basic bunny shape but normally chocolate bunnies have rounded edges I'm going to drop down a poly bevel but the poly bevel doesn't really work with the eye so I'm just going to wire it right in here after our poly extrude and let's make this I like it look at this that's the cool thing about Houdini is it's all procedural and you can always go back and change previous steps like I'm just looking at this and I think that I want my bunny to be just a little bit thicker so you can just go back and make it a little bit thicker and then you can go back and move the eye cool I like it so we have our bunny let's drop down a Knoll now we need to turn this object into particles to make it into a liquid so I'm going to go to my shelf tools here and click on melt object and down at the bottom you can see select object melt click your bunny press enter and as you can see it turned my object into a bunch of particles and later these particles are going to be turned into a liquid mesh so if I hit play right now it's just going to fall through because if you remember from last tutorial we're going to need a ground plane now it's just going to sploosh on the floor but that's not really what we want we want it to melt from the top like it's being baked by the Sun so a Houdini created these notes for us when we clicked on the Shelf tool let's go to our Auto dot Network and if you remember from our last tutorial our top network is basically our solver that does all the computing for us it's our simulation so we're going to be introduced to this jumble of mess just press the key L and that'll organize everything for you and a couple of the key points I wanted to show you guys without getting too complicated here right here is our flip object and up here's the particle separation now a basic rule of thumb for particle separation is the lower the number the more particles you're going to have and the better your simulation will look and the longer it will take to simulate and so let me refer to you down here on our timeline right here do you see this blue bar that's what's already been processed that's already the the computer doesn't have to simulate this or anymore because it's already been temporarily saved and if we click on it forward right here it has to get up to that frame the computer has to simulate it so we have to wait so for our coin-flipping we didn't really need to worry about this because it wasn't that complicated of a simulation so it didn't take that long to process it it was pretty much instantaneous but your computer is going to have to calculate all of these particles so it takes a little bit longer eat larger your particle separation the less time it takes for this to cook basically there's a couple of parameters right here I wanted to show you as you notice it just melts right away and to basically solidify these particles we want our temperature to be zero and we also want a really high viscosity to make it really thick let's say let's see how 10000 is see how it's just solid but I can still see a couple particles just moving just a little bit let's just add another zero all right that is a solid chocolate bunny another thing I wanted to show you to make your top cooking a little bit quicker is do you see this box around your simulation everything in this box is being processed and we can reduce the size of this box to make our cooking go by a little bit faster so if you click on your flip solver you'll see this box and we can shrink this box so then it's less area that this has to cook so we have our bunny now we wanted to start melting from the top to do that we're going to have to create a heat source the easiest way I found to do it is to drop down a geometry and we will name this heat source and let's drop down a sphere let's make it 50 rows 50 columns and we're going to raise it up above the bunny just right above and let's add a mountain note and what the mountain note does is just creates a bunch of noise and you can mess with the parameters here just makes it really bumpy so then as its passing through the bunny it doesn't seem like just a smooth ball is going through it make sure that it's completely over the bunny let's drop down a transform and make it just a little bit bigger okay that looks good to me now I'm going to keyframe the y-axis at frame 1 alt left click and about halfway through our simulation we'll do it one twenty oh hey this is another good lesson so do you see when I clicked on one twenty it's just going to start cooking for all that time if I don't want to wait for that because I don't need to see my simulation right now you can hit escape cancel out of that and do you see this brain right here if you click on that so there's this disable sign that will means that it won't simulate that means I don't want you to cook anything but then our bunny disappears so let's just click on this display flag of our bunny right now go through here and at one twenty I want my sphere my heat source to paths pass through almost all the way and I'll left-click so now my heat source is going to slowly move down the bunny let's click on our brain let's save because it's always a good practice to save now let's turn this into a heat source so I'm going to go up here and my viscous fluids click on the heat with an object and it's going to say what object you want to heat with so I'm going to select this press Enter what fluid do you want to heat and I'm going to click on my bunny press Enter so we it turned into this cloud looking object and it added a node to our top network called heating volume and the one thing that you kind of want to pay attention here is the output range basically the higher this output range is the faster it's going to melt your liquid and I did this once before and one seems to make it look like melted chocolate if you want it to be really water like I would raise this up more but one seems to work for melting chocolate so let's just sit through this and let it cook and see what it looks like okay we're all done and there's a couple things I wanted to point out as you see our particles right now are black and as our heat source passes through it to represent the temperature it turns it from red to yellow to white and white means that the temperature is really hot and that makes our particles start to melt and I like the way that's looking but if you want to change a couple things I would go to this flip solver and let's increase the substeps what sub steps are is you have your frames and the simulation does a process each frame but your sub steps are processes in between each frame to make it look smoother so from frame 1 to frame 2 instead of 1 process it does it at 1.5 and then 2 and it just makes your simulation look smoother but the better you want your simulation to look the longer it's going to take to cook if you want it to be thicker you could consider increasing the viscosity and the density like I mentioned before if you want the heating source to really melt your particles and turn them water like you could increase the output range so since I'm pretty happy with how this looks I'm going to decrease my particle separation now something like 0.8 but you can do it lower do you see how there's a lot more particles in this now so I think we have our simulation how we like it let's go up one level and turn off our ground plane and we can turn off our heat source it's still going to be there we just won't see it and we don't want to see it now let's go to this geometry right here called Bunny fluid and there's a lot to unpack here but basically what this does is turns your particles into a particle fluid surface like a mesh so it looks more like liquid instead of just a bunch of particles moving down one thing to touch on here is do you remember how we talked about cooking your simulation and waiting for this time line to go and it takes forever especially when your particle separation is low and you have all these extra sub steps if you know that it's what you want then you can cache it so it saves that simulation forever so it will just always play you don't have to read change it obviously if you do want to change something afterwards you're going to need to cache it again but what I would do now is let's go to this compressed cache right here and I'm just going to name this compressed and it's basically at first its going to cash a compressed version of our simulation and then we'll go to the next step after we cash this compressed version of our simulation okay so now that we cashed the compressed version of our simulation we can kind of see what it looks like if we hit the display flag right here and do you see how it's all blocky right now if you click on the load from disk it's just going to pull the saved simulation so you don't have to re-cook it every time now let's check out the particle fluid surface so if you hit the display fluid surface you'll see that it's made this fluid mesh out of our chocolate bunny and it's looking pretty good one thing that I would recommend checking out is clicking on this node and going to the filtering tab and here you can change a couple things like making it smoother adding a final smooth you can change any sort of parameters right here like median value Gaussian mean value I'm just going to check all these and it's looking like a pretty good chocolate bunny to me so let's save this now if we click on the display flag here and I'll just call this like surface and this is going to take a little while as well okay now that we've cashed our simulation completely click this load from disk and click on real-time and we can just watch our fluid hopefully melt like a real chocolate bunny love it now all we have to do is make our simulation look pretty so let's drop down a floor I'm going to use a circle you can use a grid or whatever you'd like get our floor now let's drop down that background and I'll make this into a grid and we can make a camera so now let's make a camera if you hold the ctrl and left click on your camera it's just going to make a camera pointing exactly where your view board camera is facing right now so you'll see that we have these transform handles here and it dropped down to camera note for us let's go through our simulation and see kind of what it is a nice angle here we have our background we have our table and I'm actually going to animate the camera just a little bit here just I want it to slowly pan away from the bunny because an animated camera is always more interesting than a stationary one so I'm going to all-n left click on the translate and the rotate on frame 1 and then let's go do frame 240 and just pan out just a little bit alt click left click alt left click so we have our camera set up let's add a light I'm going to use an environment light I have a nice outdoorsy HDRI that I'm going to use and let's make it a little bit brighter too so now let's apply our shaders it just so happens that Houdini already has a milk chocolate just click and drag that tor Bunny let's make a shader for our table make a shader for our background and I'd like to do some nice springy colors maybe a green let's see what that looks like well no I don't like let's do it like a blue and we'll make the background the green okay let's see what this looks like in our render view all right and if you want it to just render a section hold the shift key left click and drag the box on what you do want to render and it'll be a little quicker because there's not really any point of rendering this background the green is looking a bit neon to me it's not really reading spring so I'm going to change that maybe a little darker but I am liking the look of that a lot cool I think we're ready to render this bad boy so let's go to our out and our mantra node rendering I'm just going to do a nine by nine change this to physically based rendering you can change any of these that you want maybe a good idea would to be your subsurface scattering to increase that because of the milk chocolate has a little bit of subsurface scattering on it the default shader does anyways maybe you might want to increase your reflection on the ground but other than that I think we're ready to render this so we can just go to render to disk and I think that should be all for me today guys thanks for watching and please let me know if you have any suggestions or if you are an expert in Houdini if you have any better ways of doing this I'm always open to learn more that's the main reason why I'm doing these tutorials is to learn more myself and the best way for me to learn is through teaching so if you have any suggestions please let me know and if you are a beginner let me know your thoughts as well is there anything that I wasn't clear on that you'd want to learn more about or that I do a good enough job explaining on how I went about creating this simulation just any feedback is appreciated and I hope you all have a hippity-hoppity easter bayi [Music]

Channel: Missing My Niche

Views: 1,416

Keywords: erikmineer, sidefx, fx, houdini, sidefxhoudini, vfx, sim, simulation, cgi, cg, video, videoeffects, effects, animation, animator, graphic, graphics, 3d, 3dart, 3darts, computersim, computersimulation, art, render, dailyrender, film, simulated, houdinitutorial, houdinibeginner, beginner, houdinilesson, tutorial, beginnertutorial, mmn, missingmyniche, easter, easter2020, chocolate, chocolatebunny, bunny, candy, eastercandy, howto

Id: 1rbWdWRIQ9o

Length: 25min 47sec (1547 seconds)

Published: Tue Apr 07 2020