Destruction FX | 2 | RBD Simulation

in this video we're going to set up um uh some forces and a rigid body simulation to destroy the house that we've made so far that's fractured and got all those nice constraints in it that we've built previously and we're going to do everything inside sops um if i hit tab and go to rbd you'll see we have a rbd bullet oh let me do that again if we go to rdb you'll see we have an rdb bullet solver let me drop this in so in the last few versions of houdini um they've made accessible a lot of the dops tools inside sops things like vellum rigid bodies pyro and the advantage of that is we can do very quick setups in sops you'll notice we've set everything up in stops or prepared all the geometry you can do that anyway with all those nodes it's really handy because it sets up a lot of stuff automatically for you rather than doing it manually but you can either feed them into one of these um dop solvers or into a proper dopp network if you're doing a proper dopp network the advantage of that is you can do much more complicated simulations and have different things interact properly with each other things like smoke and cloth etc whereas if you use these sort of solver versions um they're limited so i can only really do rigid bodies here i can't get sort of bidirectional behavior between this and pyro for example for that you need a proper sim but for simple stuff you can do it up here now the exercise of this series really is to try and do as much as i can in sops so i'm going to jump through a few hoops to get this to look like the actual pyro is blowing up the house but the the wonderful thing is i'm going to do it entirely in sops without having to go inside dops at all in fact if i go inside dops and i try and make some nodes you'll see i don't have any nodes available to me because i'm i've haven't got the um effects license which is fine but you'll see i'll still be able to do pretty much um what i'd be able to do in dobs anyway a bit later on in this series we'll actually look at what you can do when you go inside dops and how you can take this a bit further but um i wouldn't set this up this way if i was um going inside dops but i'll show you what i mean when we come to that because there's a few caveats things we have to jump through so the first thing we want to do is just wire in these outputs to the inputs and we'll turn this on and our solver will start working with our bricks here now we're not going to see anything if we hit play because um everything's all glued together so in fact let me just delete the glue constraint let me plug in that one so you'll notice there's no constraints there now and um what i want to do actually is come all the way up here to the rbd configure and let's turn off the sleeping because they're sleeping um they won't move until forces actually hit them so let's turn off sleeping so they're live and we've turned off the glue so in the rbd configure if you remember go to those tabs and turn off the sleeping in all of them and then just break the glue connection the constraint connection here to the bullet solver and then when we press play what we should see is everything start to collapse under gravity because the the solver is doing its thing you know they've bubbled up just what we need from dops to hear into sops and you'll notice actually if you select this node the rbd bullet solver there's loads of settings that they've given you so you can control your simulation now the first thing we notice actually is look they're all falling through the floor the reason our bricks aren't falling if you remember is we made some of these passive so everything else is kind of resting on those but you'll see our doors falling through there is no ground plane there so we've got a couple of options the first option is we can either go to ground here on the rbd bullet solver node there is a tab for ground so that's in the solver tab and then we can click on the ground tab and we can add a preset ground you can even plug in a height field if you wanted you can just map it there or just a ground and this is just a an infinite flat plane or if you wanted to plug in your own geometry you could just for example make a grid and just plug that into this fourth input the collision geometry let me turn off ground plane and look you'll see if i hit my frame there's my grid as a blue collider if i just make that bigger we'll see we can scale that up and we could use that to collide with instead in fact the visualizer slows it down a little so i'm going to click on the rigidbody solver node here click on the visualize tab and we can turn off show collisions so we're just we're not displaying that but now if i press play um it's going to collide with that ground plane and um you'll see they don't fall through the ground anymore so hopefully the bits will just there we go they're seeing them start to collapse but they're not falling through the ground and there's no glue holding them together that's all good so um what i want to do now is uh create a force to explode this with so we've got our bases of our sim we've prepared everything we can see if we press play and we've removed all the constraints everything's collapsing and breaking up as we want you see sort of the nice glass shapes and the wood shapes and all the bits that we defined a lot earlier so um let's create a force of which we can blow this up with so a traditional way really is to start with a sphere and just sort of make a noisy sphere and use that let's template um this constraint node so we're not contemplating the sim and we use this as the basis of our velocity vector so we want a load of radiating vectors shooting out and we want to control those so this is the way i like to do it or one of the ways when we come to use this for pyro we'll actually change this for one of the new houdini 18 tools but i'll show you that near the time but for now i'm just going to create a quick proxy one with the sphere so this is one way to do it so we have a sphere here let me turn on the uh smooth wire shaded and that's a primitive so let's turn this to a polygon maybe increase the frequency quite a bit and i only want half this sphere i don't want any forces radiating under the ground so i'm going to make a clip sop and the clip stop will allow me to clip the geometry based on a plane so based in the y direction here and i can move that up and down the y direction but 0 is essentially the origin and that we've clipped our sphere in half and uh we don't want it nice and smooth and radiating we'll add a bit of noise to that so we'll add a um a mountain sop that'll just deform a lit to form it a little so yeah i kind of like that we've got a bumpy sphere and you'll see it's inside the um house here so it's definitely going to explode quite nicely and then what i want to do is scale this up and down like an explosion so i'll create a transform node to do that and what we'll do is we'll just set the uniform scale to zero and maybe go to frame three let's set a keyframe so let's right click choose keyframe set keyframe so uh and then what we'll do is we'll maybe go to frame five so let me just step forwards for five and then um we'll set this to a one change that to one right click keyframe and then we can choose let's do that again right click keyframe and then commit change there we go so our sphere just suddenly appears push like that so i'm going to create some velocity vectors based on this and that's easily done we can use a trail stop so a trail stop will plot the point positions and calculate v for us if we set this here to compute velocity if we go to wireframe and turn on display velocity here we'll see those vectors it starts off as zero and then when it stops moving they set to zero as well so we've got those kind of rushing through which is quite nice and um we could actually add a bit of noise to that if we wanted let's um see where those vectors are here we go so to add a bit of noise we could add um on top of this a uh point velocity node so not only do we have the velocity based on the the motion um we can also add a bit of noise with this point velocity so you'll see it just keeps the basic value coming through and then we can go to colonoids we can add some colonoids on top of it so you can sort of add a lot of noise and disturbance there if you bring down the pulse it goes a bit quicker and you can change the scale with swell size here so we just add a bit of noise to that now the downside of this if you look when we're at zero we actually have some velocity now and when we've stopped we still have some velocity so if i look at the spreadsheet you'll see v has a value when it's stopped moving that's because of the noise um what we really want to do is animate that noise on and off with the same um of the scaling here so what i'm going to do is where it says uniform scale i'm going to right click and copy parameter and in here on the point velocity in the scale i'm going to right click and paste relative reference so that's going to scale it up and down the noise accordingly and then i can multiply that further if i want so i'll add a lot of noise to that and you'll see um oh that hasn't gone to zero again has it i don't know because we didn't scale it to zero the thing let me just delete that channel instead of copying relative reference this time we can right click and actually paste um channels and expressions what that will do it'll actually copy in our curve look if you click on it now it says bezier so if you hold down shift and let and middle click on the word scale this will bring up the uh animation editor and uh you'll see your keyframes there so to bring up the animation edit editor hold down alt middle click on the word scale and that will bring that up so not only can you cross copy channels across you can copy entire animation curves so what we really want to do is actually um not really see that if we go to frame five where it's one we can go to frame six and then we can set the curl noise to zero and just set another keyframe so basically copied in the animation from the transform but then we added another keyframe at the end let's just set that to zero or you could manually keyframe it whatever you want the important thing is that in our spreadsheet our velocities must be zero on frame six so we still have velocity on frame five but not six that's important to remember excellent so we're managing that so i'm going to create a null and we'll call this forces out there we go so we can read our our velocity or our force out or whatever so how do we apply that to our um simulation if i was doing this properly inside dots then i'd go inside dops and import these points in and manually merge them in but since we can't do that we have to do everything at this level so if we look at the parameter pane here by tapping p for the um rigid body the rbd bullet solver node if you go to the solver tab here and to bullet objects this tab here and see my flashy cursor you'll notice that we've got this thing overwrite attributes so this means any attributes that we've overwritten remember we change the active on our bricks to make some active and some passive so it's going to override them every frame instead of using the ones from the solver here which is pretty cool so what we could do is um bring in our own velocity now where do we how do we do that well first of all we've just got to type v in here because that's the attribute we want to bring in and then what we want to do is transfer the velocity from this this this branch onto our rigid our bullet objects now remember what i said was let me just pop a null in here remember this first output is the geometry that we're actually going to render and if we middle click there's none of the bullet attributes now if we look at the last one this is the bullet objects or the proxy this is what bullets actually going to simulate with if we were to click on there we can see those bullet attributes things like density and bounce so it's this geometry here that's actually it's going to be looking for these attributes remember active it says active so it's on this branch we want to transfer the attributes in so let's do that let's use an attribute transfer so where's my attribute transfer node there it is let's get rid of that null so i can branch this over like this and let's plug in the force to the attribute transfer i'm going to turn off primitives and i'm just going to tick on velocity so only bringing velocity in and always the condition this distance is way too big so let's bring that down to something like three it's always too big to begin with so whenever anything's within three units of this it's going to pick up that velocity so let's go back to the bullet solver let's go back to frame 1 make sure we have v here so now we've transferred if we middle click we can see we've got v being transferred in and we're going to override it every frame from the one in the simulation instead so if we press play now so remember nothing's glued together so it should just fall apart and when our force kicks in there we go we can see our velocity kicking in and moving everything and then it kind of just hangs there in space the reason it hangs there in space let me just stop that it's quite simple really we're overriding the simulation velocity every frame we're not adding to it we're overriding it so basically when our velocity is here if we look in the spreadsheet becomes zero we're overriding the velocities and the simulation with zero every frame so it's the velocities that move everything so if you're telling it zero it's going to stop moving and freeze like this bit of a problem what we need to do really is tell this either to add the velocity in rather than overriding it which we can't do unless we dive inside dots or we can actually keyframe this on and off so we can have this overriding the attributes until the last time we have some velocity so again if i bring up the spreadsheet and just look at this node if i step forward we'll see that um the last frame we've got velocity is frame five and then frame six this is zero so what i want to do is i want to keyframe this that on frame five it's on and then frame six it's off so at frame six we're not reading in the zeros but we're gonna keep or preserve the velocities from the frame before so let's try and do that i'm going to come down here and set this to manual at the bottom right remember we did that before so from auto update to manual so this is as i move the keyframes it's not going to try and process this node so we'll go to frame 5 and then on the tick here you can right click go to keyframes choose set keyframe and if you go to frame six you can turn it off right click again go keyframes and then uh let's try that again right click keyframes and then commit change so if you go between frames five and six you'll see the tick appear and disappear let's see if that worked i'm gonna set this back to down in the bottom right it's gonna set it back to auto update and then uh let's press play and see uh because we're now overriding with the velocity until the last time the velocity is there and then uh hopefully the zero will kick it kick in after the keyframes bang there we go so it keeps moving and there we go we're not transferring in the zero any point and it's able to keep the velocities from the frame before of the sim and it basically inherits those over and we can see our house now explodes quite happily excellent so that's how you can kind of bring in velocities and control exploding things inside um your rigid bodies easily and we can use this sort of velocity force to drive our pyro later on excellent so we got that working but the problem is this is not glued together so let's pop our glue in and see what problems that causes us so now if we press play um we only have velocity coming in there but our glue our constraints don't know that they need to break so if we just wait for that you'll see we've gone past the ticks and nothing has changed um because we need to add another attribute here so um there's a really nice attribute with the glue if i just step forwards a few frames and we'll just make a null so i can pull off these constraints here so i can see the constraints and if i just look at the spreadsheet to see the attributes on the constraints remember you have to go to the primitive attributes for this we'll see we've got some that we can play with like force and impact and stuff now impact's the interesting one the impact is what drives the bullet here when the impact here is above this threshold then it will break the glue and when it's below it won't break the glue that's kind of a hard built-in feature so we just need to create an attribute to control that breaking of the glue so how can we do that we need to create sort of an impact attribute well we know the kind of velocities or forces we're dealing with here if i just display the velocity vectors in wireframe here we know they're strong when it's moving quick and then they fade off so we could use the velocities here to create an attribute to drive our impacts and that's exactly what i'm going to do i'm going to make a point wrangle here and i'm going to create a new attribute called f at impact because i just want to uh bring this one in to break the um bricks there and we'll say that is equal to now we'll type in a length bracket v at v so this is going to give us the length of the velocity vector in other words the magnitude of it so if i do a right click spreadsheet on this wrangle we can see that the impact is measuring here there the size of the velocity as the velocity gets bigger this impact gets bigger and we can see it's in the region of sort of nine if i just sort the numbers for about 15 seems to be the maximum number there something like 15 is our range and they're quite smaller impacts so let's look at how we can wire that together so we need to tell the simulation about that impact and what i really need to do if you notice the impact on the uh primitives here of the uh constraints remember that's where the impact attribute is on the constraints here so if we look at the spreadsheet remember they're on the primitives there so i can't just attribute transferring because this is not the uh attributes from the uh constraint there so the way we can do this actually is we can select these breaking thresholds in the solver and we can drive it through here let me just display the the geometry again so we can do it through here in this breaking threshold section and at the moment we're breaking all the uh soft and hard constraints we don't have any called that so let's remove that what we do have is constraints here called glue if you look at these uh configures you'll see they're all set to glue and glue that kind of thing so here we're going to affect all those glue constraints let me actually display the constraints with the null again so and we can break them on demand for example look i can break them up a certain frame so let's save frame two so if i go to frame two that'll just break all the constraints with the name of glue there you go on frame 2 they all got removed if i turn that off then they'll stay there so i can put in some controls here and look it says delete constraints it tells you what it's going to do here so if i go to frame two now and frame three they're not being removed um now remember we did call them all glue but we gave them all their own groups as well so in here you can actually specify the group so you can say look just the door glue and then you can make another tab for the other glue on the other things or you could give the glue unique names it's up to you there's many ways to do that so this is affecting all the glue i want to affect everything here i want this to all feel the impact of that explosion so um how can we uh drive that in there well we need to use basically um a bit of a bit of an expression really we need to come here and use this vex expression down here because what i need to do really is read in the impact values from here these impact values and get those to um transfer onto um the actual constraints here so the way i'm going to do that is with an expression called near point so the near point expression allows us to look at a point in this geometry and this geometry is going to be the constraints and then we can say find the nearest point in a neighboring geometry within a certain distance and tell me what the attribute value is on it so it's like an attribute transfer but we're writing it in code and that's what we're going to kind of do here so the near point expression first of all wants a maximum distance parameter so we'll type float max dist and we'll set that to three units like we did with our attribute transfer and then what we've got to do is type the near point expression now the new point expression will return the number of the nearest point to the constraint that we're dealing with and what we want to do is then take that point number and then find use the point expression to find out a value of a particular attribute in this case the impact attribute and then we'll copy that value onto the impact attribute on these constraints and then hopefully if it's big enough the glue will break now you'll notice this tight text here what i can't do is actually type a path to uh a node in my expressions in this particular wrangle you need to follow this look the second input so if i type a one which will be the second input that's actually the packed bullet geometry that would be this first or rather this third i can refer to the data in this third branch and if i do third input which is uh if i write in the code that will be 0 1 2 remember we count from 0. so third input will be 2 as in the index number and that will refer to arbitrary stop geometry anything i plug in and that stop geometry refers to anything you've plugged in down here so i'm going to drag this null down here and now i can refer to this um as input 2 in my coding so whenever i write a 2 i'm referring to this path which will refer to this node and i can read these attributes including impact here which is the one that i want so now that i've put that path in i can write the next bit of the expression so we'll say int for the point number pt so that's our point number and then we'll say near point and then we want to ask it which geometry are we looking for the near point that's in number two here that's that forces out null and then we type in at p so this is the current position of the part of the constraint we're looking at so we're picking a point on the constraint that's the at p and then we're looking for the nearest point on that forces out geometry and then what we want to do is ask it to look only within the max dist that we've just specified as being three units so it's only going to look for points within three units and that's going to return the point number we then want to uh find out with that point number the value of the impact attribute on that point so let's type float impact and uh that's equal to the point expression so again we're going to ask for the input geometry that forces out which is referred to as number two here so we ask it for the attribute we want to read that's also called impact and then we give it the inde uh the point number so we just found out the nearest point that was pt from the expression above and then what we want to do is take that impact and um add it to the actual attribute so the actual attribute is f at impact and then we can say that is a let me type that in correctly imac impact there we go and that is equal to just the variable that we made impact there we go so that should work here we've got um we're defining the distance as being three here we're using the near point expression of input two which is this guy here this null and then we're saying look at your current uh position of the locator and within three units is there a point and if there is store it here and then we're using that point number here in this expression to return this attribute from it which is storing in that variable and then we're just returning that into the actual um attribute on the geometry which the solver will read and if this number's above the breaking threshold then it will delete the glue for us so um let's see if that works now it may not work because if we look in our spreadsheet if you remember on this forces out no no our impact only really gets up to 15. now my glue if i look at my glue we haven't changed any of the glues they're up at 10 000 so i need this number to be above 10 000 or a way to control it and we can do that here in this wrangle so very simply after this length here we can type multiply and then chf and then we'll call this impact scale so we have a scalar there you'll notice it's gone to zero because we've got to click on this magic button here and then we can type a one in and we'll get back our 15 if we do 10 we'll get our 143. and i'm gonna do it by a hundred now so we've got our fourteen hundred and eighty and if i do it by a thousand we've got fourteen thousand which is above our ten thousand that we need so hopefully that's enough of a force to um break our glue so let's uh preview our rigid body solver now and uh we're bringing enough of this impact so hopefully that will feed through and actually break the glue and then the other velocities will kick in so we're doing it in this way because we need to transfer these attributes onto the constraints there and look there you go look it broke the glue or break some of the glue because remember not all the forces were up that high some weren't but we've got an interesting break up now where the glue is actually fractured based on our impact and then um if you look the rest of the building is exploding outwards so that's kind of good we can kind of scale this down a little what i'd like to do really is work in the realms of a hundreds uh mind you it depends on the forces you want to hit yeah we'll keep it in the realms of um the ten thousands here so i'm going to leave that at 10 000 knowing that um what's our peak again let me just turn this null on let's do a spreadsheet look in the uh point attributes there so yeah our peak was upper um sort of 15 15 000. that kind of thing so we're peaking at fifteen thousand and the lowest is uh seven thousand which is not breaking anything so we're going between sort of seven and fifteen thousand so uh my let's try uh some of this out so i want my glass to easily break so uh we want this sort of less than 7000 really let's put um 5000 in uh we'll keep the glass to the frames quite high um also the frames to the walls uh will make that also quite low so the frames will pop out so that's below the the lowest force that'll always break so on the all door constraint this is holding the whole door together again we'll break um we'll make that lower than a thousand though than the 5000 so that'll easily break but the wood grain here will make really high so the wood will never splinter will just will come apart in separate bits and we'll just take a zero off the door so it'll come off the hinges very easily now the bricks here we've got 15 000 isn't it let's put 11 000 so some will break and some won't now our roof tiles this will be interesting um let's do all the uh this is all the roof constrained to all the roof so again we'll make that low and then like i said on the actual fractures here let's maybe make that 13 so not all of it breaks apart and we'll just drop the where it's constrained to the roof a bit lower so it'll easily come off so the roof ridge tiles here and the uh the actual concrete tiles themselves i've made that quite high so hopefully they won't break and stay in a single tiles whereas where all the tiles are glued together i've made that quite weak so the roof should come apart and here i've made quite weak so the roof should come off the bricks easily i've made the bricks quite between our threshold so some will break and some won't and i messed around with the doors just to recap so i've made the overall door constraint quite weak but the individual splinter is very strong so hopefully we'll see it break into planks rather than splintering we made the glass very uh weak let's actually take off another zero but we kept the uh in the frames quite strong so hopefully shards will stay there and then we made the uh some of the frames will come off the bricks quite easily so we've varied quite a lot as we go down around the thresholds that we know that our impacts are running through so let's just press play and see the result of that tweaking so hopefully as we go through we should see some interesting things so that there we go if i just stop it for a minute we'll see what we wanted hopefully so that we'll see that the glass just gets pulverized and shattered very easily we'll see the um the door falls apart into its planks but the individual planks don't shatter very well you can see the frame got shattered around that and yeah look the frames came out some frames came out from the windows quite easily and the bricks didn't break apart very easily because they were at the top end of the threshold and if we look at the roof again like i said the roof overall structure broke up the individual tiles didn't so if i want the tiles now and the bricks to break up more that's very simple i can now go to my bricks and just bring down this threshold so i know if it's about 7000 pretty much it's all going to break and the same with these uh roof tiles so this one was all the roof tiles again so let's put this maybe at 800 so some will break and some won't again um and actually let's uh go to the door and uh let's let those splinter this time so if i just take the uh the wood cut grain here again we know it's between seven thousand so maybe we'll make seven five eight thousand so maybe some won't break and some will break so again by setting it up like this you can see how very easy it is for me to change the glue properties and get quite a different look and control sort of how each material should break so if i do that again we'll see now that the windows are still shattering but look the door now not only does it come apart in planks but now it's started to splinter as well which looks really nice look we're getting a nice sort of splintering in between the planks and we'll see the roof now even though we've got the individual tiles a lot more of those tiles are being broken which is really nice we get this sort of nice and you'll see all the bricks totally have been pulverized into their clusters maybe i'll just increase the bricks a bit more maybe 8 500 or something like that now there's another thing we can do actually on the bullet solver sometimes these pieces go a bit wild so we can actually go to um where is it on the solver node on forces we can actually add some drag and some drag spin this basically just adds some air resistance to those pieces and stops them going too crazy or wild so um i'm quite happy with the way this is going what i will do is let me just uh plug this last null in and then let's turn on the smooth wire shaded and uh what i want to do now is just um let's just save it is to flip book this up so we can see how the simulation is going to look so to flip book i'm going to right click on the flip book icon here and bring up my new settings and i'm just going to turn the resolution off here so it'll do the size of the window and i'm just going to hit start and let that run through so i'll pause the video while that cache is up so now the flipbook's complete if we press play we can see that it explodes quite nicely and it goes out quite a way if i just zoom out a bit more actually um we can see that it blasts out all those pieces for quite a distance maybe i'll just run that book up once last time now we're a bit further away and so we can see that we can control the velocity in uh we can control the impact and uh we can control some of the fracture shapes we get and also the strength of the constraints um really does make a big deal if we just go back here again we can see the door breaking up the way that we wanted by managing the constraints there and again you see quite a nice explosion um that suggests that house is blowing up and we'll use this as the basis for our pyro sim i won't actually use this we'll set it up slightly differently but we'll check that it works with this but um i'm quite pleased with that one last thing if i did want to scale the velocity if we look here on our point wrangle you can see we made the impact and we've got a control to scale the impact here what i'm actually going to do is create another one so maybe i can tone down that velocity or scale it up at this point so if i thought it was too strong i could tone it down or vice versa so that's easy we can say v at v equals v at v and then times and then we can again just type chf call this velocity scale don't forget your semicolon and when you click your magic button here you'll get your scale there so if we put it to one it'll be what we just saw which i quite like maybe i'll just bring that down a bit maybe point nine so um interestingly what we should really do is do this after after this guy here so these are truly independent otherwise when i scale the velocity i'm going to be scaling the impact to whereas if here i'm reading the impact first and then i'm going to scale up the velocity afterwards so it's better to do it that way that way these two are totally independent of each other so uh just a quick sanity check if i press play now i should have a very very similar explosion just without those bricks flying quite as far we might not notice 10 percent less velocity when it explodes um but there we go it's exploding happily now i haven't sort of affected the impact scale which is uh really kind of cool so again actually that's going to affect all my nice glue but we're going to come back and tweak all this when we create a slightly different force in there so say you're happy with all of this where do you go next well the last logical thing really is to bake this or cache it to disk because once i cached it to disk i can then use it as a collider for my pyro sim so even though the pyro sim will inflate with the same kind of explosion but i wanted to collide with these bricks um to suggest that it was uh actually causing that explosion to begin with so i want to cache this up so again we use our rbd io so that's very good at caching all these things up and again we can if we want to cache up all the geometry we can plug it all the way in like this which i'm going to do and then let's color this one blue as well and this one will write out the entire simulation so in this case i do want to do the frame range in fact i don't want all 240 frames i'm going to select the frame number here at the end and let's do 75 i'll only worry about the initial bang so there we go and you'll see here we're only going to write out 75 frames of cash so i'm just going to change the name here i am going to leave this dollar f because that'll be the frame number so then we'll get one frame for each sorry one cache file for each frame which is the best way to go and we'll call this house explode we'll version it version one there we go so all that's left to do now is save the scene and hit save to disk and uh what that'll do is that'll process that it goes quickly because i've still got some cache and then it will write out all those 75 frames to disk and obviously if you change anything you're gonna have to re-cache it all again but i was quite happy with what we saw and i think that's good to move to the next stage which would be to um actually really rebuild this in pyro and get the pyro sim to um work with this before we then try and render everything so it looks like our house is exploding so there we go it's written out all our 75 frames that was a fairly quick um and then once this is done here the last thing i'd want to do is click on load from disk over here to load back in that geometry and then we can just check it by flip booking it if we want to and like we saw in the other rbd i o nodes you can choose up here what data you can get it to write to disk for you so i'll just pause the video while that catches up with us so that's finally caught up with us if we turn on load from disk it will now read in that geometry so if i just pop in a little null here and look at the actual geometry that we want to render we should be able to drag through backwards and forwards and we'll see it's reading that explosion back from disk for us that's excellent that's exactly where we want to be so let's just turn that on i'm going to save this scene and what we'll do in the next video is we'll set up our pyro with a similar force and then we'll probably recast this out and we'll look at how we can add pyro to the equation and make it look like our explosion has destroyed our building

Channel: Houdini

Views: 6,318

Rating: 4.9578948 out of 5

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Id: i3qQvQwJYbE

Length: 38min 36sec (2316 seconds)

Published: Mon Nov 23 2020