Houdini 18 - Building Destruction - RBD Bullet Solver

howdy guys alright so in this video what I wanted to do was walk through the new RBD stop solvers that are available in Houdini 18 and I wanted to go and set up a whole sim so what we're gonna do is we're gonna build this building we're gonna set up the sim then we're gonna destroy it alright so we're gonna walk through a lot of cool techniques for this stuff so let's get started okay so to get started here what I'm gonna do is go and create some sort of building type of structures so I'm just gonna call this building like so I just create a geometry node and I'm gonna go and drop down a grid here inside of my building note there and I'm gonna set the size to something like let's say 3x3 I'm just gonna make something like a simple tower with many floors on it alright now we're gonna go and really sample this that way I can actually go and grab a bunch of new sections of this and create walls out of it so I'm gonna say that you know every wall maybe is about two meters and let's say we're gonna resample by polygon edge like so awesome and we'll leave it on like that and the next thing I want to do is we're gonna drop down a convert line node go and this will then turn this into a bunch of different individual primitives there alright cool so then I'm gonna do a carp here really quick and I'm gonna do my equal offset trick alright so I'm gonna go and copy the first you paste it into the second you as a relative reference and we're gonna do one minus this way I get an equal offset on both sides of my individual segments there cool so with that let's drop down a new sweep node here alright and we're gonna utilize the ribbon feature for this because I'm basically gonna build the basis for these walls here awesome and then with that let's go and drop down a copy the transform node and let's just move these guys up let's say three well actually let's do two and why and we'll make a bunch of copies for this do something like yeah five copies is fine then let's drop down a skin node and we'll skin that together so we actually have something so we're gonna have to actually utilize the skip every endpoint and just get this guy situated until we are good alright so now we got a bunch of walls let's go and create the individual floors now so what I'm gonna do is branch off over here and we're gonna do a poly extrude alright go I'm gonna hit shift us on the keyboard to get a different wire look and then I'm gonna go and just lift this guy up so this is gonna become my floor all right I'm gonna make sure to output the back because we're gonna fracture this with the material fracture node and so we want solid objects for the most part all right very cool so before I get too far let's make sure that we actually capped these guys as well you can see we have open ends there so let's drop down a poly cap node like so and we'll just cap all those guys off again so we have solid pieces of geometry all right so let's copy this copy and transform node and I'm gonna wire that into this guy right here to create all of my floors alright with that we can now merge these two guys so I'm just gonna hold down alt on the keyboard hover over my output and then just left-click and drag to create a merge node just to see how things are coming a lot all right I might be kind of nice to to also have some horizontal structures on the outside there so let's go and actually let's redo that again so it's marriage this guy again there we go well let's go and copy this guy and let's pull off from the grid again alright and then let's use a sweet note for this awesome and we're going to set this to a surfer shape of a square tube and then I'm just gonna put the columns down like so and then we'll output this guy into that same merge node there awesome let's make it a little bit bigger cool yeah so now we're starting to get a nice little building now we just need some pillars for the outsides there that is looking pretty cool so far so this is a relatively easy as well so we're gonna do is we're gonna need to get this guy because it's where all the points are so I can go and copy a grid to this as well so let's do that we're going to do read and let's make a little bit of space for ourselves over here and I'm gonna drop down and copy two points and we're gonna wire that in for the first input and that for the second input and let's go and set this to 1 and 1/4 the size let's put it also on to the XY plane and put in two and two for the rows and columns and while we're at it let's just hook this guy up because I just want these guys to be square and then I'm gonna make them just a little bit smaller awesome so now all I need to do is just extrude these guys up so let's say Polly extrude and we will extrude it up by 2 and we need our make sure we reverse this guy up here there we go and let's now put the back so we have a closed shape that we can utilize our copy and transform node to make a bunch of copies of those guys and that will basically merge that in there we go we just need to make sure we don't do the last one so let's just do four for this guy awesome so now we got a building that we can destroy cool all right so the process for this is to first just go and set up a material fracture node so an rbv material fracture node we're gonna take our whole building here and just pump that right into that first input and what I'm gonna do is leave it all in the concrete type you can welcome to try out these other ones just keep in mind that the wood material type will take quite a while to process all right so let's take a look at the results here sweet so we got you know nice fractured piece of geometry and we want to go and destroy all this stuff but before we do I want to go and also turn on my chipping here and just walk through some of these particular features of this awesome so basically what it's doing is it's creating these little chip pieces so we can actually increase this to something like point eight and that will add even more chips yeah we can also do the corner depth so if we do something like point one will get bigger chips this is really cool for these types of simulations because it basically are these little chunks that you know start to break away from these large chunks makes it look just more realistic yeah all right so I think I'm gonna go with that okay so the next step to get this rolling and it's a drop down an RB D bullets all very awesome and what we want to do inside of this are B D bullet solver is turn on the ground right off the bat that way we have something to collide with so I'm gonna turn on the ground and we are good to go if I actually hit play right now we will get this guy falling to the ground awesome look at that pretty quick to get a really nice simulation set up but it goes even further and what I'm going to do is show you guys a little bit about the constraints before I close out this particular video all right so let's stop that and let's go and why are in this little pink dot right here that's the constraints that the material fracture node is actually creating for us all right and if we were to actually go down and drop down and our BB explode node where are you let me actually type there it is exploded view all right so if we're to actually pump the geometry and the constraints into this exploded view and turn that on and then check on show constraints you can see these are all the constraints so they're little wires think of them is like glue that's holding all these pieces together and they all have different you know strengths so if I were to actually go and turn on the constraint strength you can see that we have these values from blue to red and the differences in their strength and their bond to one another all right so with that let's take a look at our simulation now okay and I don't need that guy own anymore cool so now I've got the constraints all hooked up let's hit play and you can see the building is not doing anything well why is that well currently if we go back to our material fracture node and we go into the constraints tab our primary strength currently is set to 10,000 and that's really strong so let's set this is something like 1,000 let's see what happens let's go back to the beginning of the timeline hit play now we're still getting pretty strong values all right so let's go and put this down in something like 400 all right and we're still sticking and that is because we are utilizing currently the chipping features and the chipping glue strength is pretty high right now too so let's set that one down to like a hundred and that'll just make it so the chips will fall out first all right so let's hit play and we're still not getting anything in this because we need to go and turn on this fracture per piece so I'm going to set my timeline back to 1 and turn on fracture per piece all right so with that all set up let's hit play after it's finished calculating here which you know the more you let u fracture the longer it's gonna take for these simulations to get done but that's what I'm keeping it relatively simple alright so there we go we're rolling so you notice now that the chips are gonna fall out first so if we were to zoom in here a little bit so the little chips are falling out of the building first and once it starts to lose more of its structural integrity because we have the primary strength set to 400 the rest of the building will salt start to fall as well so what this role here for a second longer see if we can't get the building to fall looks like it's starting to buckle a little bit over here and there we go so finally enough chips fell out of the building and now the whole thing is just coming down very cool all right so hopefully that clears things up with the constraints and just how to start to work with them and start to adjust it for the look that you're going for for the building the last thing I want to show is how you can add a custom force to this so like what let's say I want to you know have an explosion at the bottom of building down here so let's just say maybe right over here what I need to do is I need to come over here and I'm going to drop down a group node and I'm going to take in the proxy geometry that's coming out of the material fracture so that's that third output right there and I'm going to call this the blast points like so all right and I'm going to set the group type to points very cool and we're gonna go and we are gonna turn off our base group and go to keep it within bounding regions and I'm going to set it to a bounding sphere now you can use a box as well I just really want to simulate more of like a you know an explosion blast so let's move this guy over here because I want all these points to be affected by the initial blast all right so we're gonna determine an area on our building where the blasts will be affected the most basically you just want to blow away this whole bottom half and just have the ball tip building just fall down all right so on those points what I'm gonna do is I'm gonna drop down a point velocity node like so very cool and we are gonna go get this name here for the group put that in the group here because this is looking for a point group all right and in this case I want to use the conical noise all right to simulate something like an actual explosion awesome so I'm gonna actually drop my direction in Y down to 0.5 and make this in 1 in the Z direction all right so just reference your little gizmo down here and then let's set the scale to something like 30 and then what we're gonna do is we are going to then pass the output of this into the proxy geometry for our RVD bullet solver node all right so let's take a look at that now so let's go back to the first frame in timeline hit play and we should see a big blast down the bottom building right there like it just got exploded awesome and so I'm gonna let this run just a little bit longer so we can see the full effects very cool and that is how easy it is to set up so the last thing I want to show when this is all done running through here I might speed up the video just a little bit I just get through the sim as I want to show you guys how to cache all this stuff out so you don't have to actually resubmit every single time you want to take a look at it especially when you want to go to render this out all right so I'm gonna clamp it out there at 160 frames go back one more frame alright so let's just put in hundred and sixty-four here ya and take a look at that one more time because it's cool alright so the next thing that we want to do is we want to drop down a file cache node let's do that alright so let's go and take the output of our bullet solver and put it into the input of this file cache and what I want to do is I'm going to hold down ctrl + shift on the keyboard cuz I want to set my own custom frame range here we're gonna say 1 - 160 and I'm gonna go and pick a folder location so I have a project currently and I'm gonna select the cache folder that I have in there and I'm gonna call this let's actually just use this name over here quacks you'll call this BLD go1 and then we need that BG OSC and then I'll just put a dot dollar F for the frame number and with that all we need to do is go and hit save to disk and what it'll do is we'll write out the whole simulation to these bgo files alright that way we can then once it's done it goes pretty quick we can just sit hit this little check box to load it from disk and we can come down here to this little button it's a little brain I don't you turn off all simulations but you can see now we still have our building destruction running really fast there we go and you can see that dynamic simulation is disabled alright so that's how you build a building really quick it's not a fancy building but it gets the job done and how we set up a really quick destruction simulation using the new RBD bullet solver node and this material fracture node and how to actually add our own forces and then finally how to cash it out to files all right hopefully that helps thanks so much

Channel: Indie-Pixel

Views: 59,228

Rating: 4.9747543 out of 5

Keywords: Houdini 18, Houdini, Houdini RBD, Houdini Destruction, Houdini Procedural Modeling, Procedural Modeling

Id: V1K_XjMvgag

Length: 15min 12sec (912 seconds)

Published: Sun Feb 09 2020