Glass Geometry & RBD Connected Face Node with RBD Tools in Houdini

so let's start with the Chi on the Sri note I'm gonna drop down a cube I'm gonna move the cube higher so it's on the plane so now it's singing right on the plane ground plane and another transformation node this one is going to squeeze it on the x-axis so it's super thin even more Center okay so I have a panel other transformation ode this one's just gonna make it bigger so I'm gonna make it like five times this back and this needs to be a lot thinner or maybe two sir okay that's good so the basic shape of my glass a glass panel next we're gonna use an RBT material fracture so if you come here tab just type RBD it will list all the RBD tools now this the set of tools is quite new in Houdini I think it was first introduced in Houdini 17 or 17.5 I'm not too sure which one I started using it in 17.5 but as of Houdini 18 side effects added a lot of new features to the RVD tools so we're gonna check out some of the RBD tools in general and not just the new features in Houdini 18 now the first one we're going to go over is the RBD material fracture okay hook this up material fracture has foreign inputs geometry constraint geometry proxy geometry and warned or points so the fourth fourth one you should be familiar with it's like the war nor in the war nor fracture oops for or no fracture not you would input your geometry here so I was just like oh my god and then you're you would scatter a bunch of points and this would be where you plug in your points so I could put in or I saw offset so this might look a lot familiar scatter node so now I have a bunch of points scattered within the volume of my geometry and these points could would go into the second input of the vorn or fracture these are the worn or cell points so these points are very similar to this fourth input there's a lot more to this material fracture and we look in here they're in the primary fracture tab there's one and two there's it two fractures are happening and I'm gonna I'm going to take out the second one I'm sorry I'm just gonna focus on one fracture one level of fracturing it already has a scatter from volume so this is doing it automatically within the RBD material fracture it's already doing it automatically it has the isolate it's doing the I saw so scatter sort of thing within the note it's all built in you can easily change the scatter points to let's say a thousand so we'll have this now the reason why it looks different from the foreigner fracture is because there's a material type fracture so right now it's fracturing it treating the fracture as if it was a concrete concrete floor or something we're gonna be using glass a little later I'm just gonna stick with the concrete for now if I sure I'm gonna go with zero so I don't want to use the scatter points for the RBD fracture I want to use my own points so let's add a point I'm just going to use one point let's move this up okay now I'm just gonna hook this here to the fourth input of the orbiting material fracture now nothing's happening and it's not fracturing that's because we have two primary fracture cell points we there's a input point now we have to check this in order to enable it now still nothing's happening that's because concrete requires a few more inputs in order to have some anything interesting to happen but I'm gonna use glass now this is much more interesting oh let's try let me try and template it this way I'm gonna make the background darker make the point size nine so it's not exactly right there so after you switch it over the RBD material let me turn this off our visit material I switched it over from concrete and I heard when I was concrete I already had this chucked but once you switch it over to glass it's the UI changes and the input points are disabled so I have to check it again okay now it's using it now I do not want to use scattered points so this is additional built in scattered points on the RBD material I only want to use my input points so I want to uncheck this one there you go so this is a bit better template like okay there so now we can see our point is affecting the way how our glass is fractured so we know we have something interactive I'm gonna say I want to somewhere in the middle yeah right here let's make it let's make it in the corner so now we can take a closer look at this we can tweet this further you can see that it has this these circle fracturing like a spiderweb we can actually control us some of the features of that come over to cracks no radial crack number no this is how many cracks you want but I want to control the spacing between these circles now that's in concentric crack minimum width now I'm going to increase this to now before I increase this I need more circles first so increasing making this bigger will only will only make the width larger within this region because the noise that defines the concentric cracks is set to this fixed size already defined us this much so by making this if I increase this this will just make it less less circles because it's limiting how much the width between this larger circle and the smaller sir however it's not making more radial cracks it's not increasing the radial crack area that makes sense like I want more cracks sort of like that's where this discontinuity size comes in because what I'm trying to say I'm gonna make this 5 so now I have I've expanded my concentric crack is what I'm trying to achieve however there's too many lines here there's too many the circles are way too close so that's where the minimum that comes in this I'm going to put in point 5 so this is a lot better this is nice less 2.5 okay okay this is pretty good now let's come over here the chipping I'm not going to be using chipping for the scene so details let me disable this noise edge noise and you'll see who now you know what it is once you disable it it's just without the noise edge noise it's just straight line this edge noise makes it way more interesting like more it gives it a more organic feel constraints this applies the glue but I don't want to apply it here so I'm going to disable that for now now I'm gonna throw on a glass material first I'm gonna call this glass I'm gonna start by coming over here I'm just going to throw in a very quick material set up a camera I give it a simple dome light gonna turn off the IPR simply because I just want it to render all at once when I turn off the employ change the camera resolution to 640 to 640 okay so we have nothing I did not attach the material okay I'm going to turn off the background for the lights okay let's go back to the class material make sure the refraction the weight has a value of one so this is how it looks rendered up when rendering the orbiting material fracture with a very simple class material now the class material is completely transparent so we are relying on this dome light to power to light up the scene the glass material since it's transparent it doesn't really there is no color so it highly belies on light in order to render it out now I've increased the intensity of the light I lowered then times daylight to 0.3 and exposure 2.2 there's no HDR map it's just a plain simple don't light let's go back in here what I wanted to show you is that rendering this glass material like like as is is not helping because well as you can see our our class hasn't fractured yet we haven't even destroyed it yet so we shouldn't really see these these cracks in the render it should look like a whole like like a whole glass material that is perfect but when we render this it's already rendering with all the lines in the middle now in our BD there's something called come over here our beanie there's something called our BD face connected faces so let's put this down now what this does this creates a bunch of attributes in the primitives this is the data that tells it what records all the data of all the faces all the primitives and gives it an ID and then it records the distance between the current face and all in nearby face all that Jason faces and of course the distance of it it doesn't this does not affect the geometry in any way other than adding more attributes to it it doesn't change the geometry or anything what we need to do is add another RBD node called already disconnected faces so we need it use okay let's drop this down first sorry we need to connect the geometry output to the RBD disconnected faces now what this node does it uses all the attributes that were created by the RBD connected faces it uses all these attributes and it will decide what to do with it should we create the attribute but that's not what I really want I want it to disappear I want this to help me remove these lines all my ones that is a whole because art hourglass is a whole right now and all the pieces near by each other are right beside each other so the distance is very minimal it's wrestling it's the distance it's wrestling if it is wrestling just pleat it so delete the connected faces and what this will do then get rid of all those line this node here RBD connected faces notice doors the distance between the primitives of each piece and neighboring pieces of rounded so we get all that prim distance data and recorded only attributes this node will use it to decide whether to render it or not and what is actually happening behind the scenes let's throw down an exploded view the internal side inside faces are being deleted that's what this note does now this is handy for rendering simulation now we haven't cracked we haven't destroyed this glass so it's not apparent why this is handy how how do we'll use this so let's move this aside let's just put put them in black because this was just to show you what it does let's go back here I'm gonna add the bullet solver now I want to mention that the art bt tools now allows us to add the RBD bullet solver on to the salt level and we no longer need to drop down a thought nut set up the RBD simulation inside the dominant and drop down a top import know to extract all the data back up into the salt level this new feature of the RBD tools has a way more convenient workflow and saves a lot of set-up time for someone new to uni this will be way more intuitive than trying to understand the dotnet and dot import notes in a bone solver has a lot of them puts the first one is the geometry so we know what this is that that's this one actually I should show you in the RBD material fracture so the output is geometry and strain and proxy geometry now let's put can put a render flag here this is just the john tree this is this John tree now let's hook this up to the constraint this gives us a visual representation of the constraints which are just primitives very much like the velum workflow this is the constraint are primitive their edges their actual geometry representing the constraints now if we put this to the proxy Jean tree it will be this is a low poly version of the high quality John as you can see the difference between let me turn on the points if the point saw is a little lower so you can see I hope you can see these points are jaggedy they have a London noise they have a lot of detail on them the low quality one there's a lot less points now why would we need a lower quality version of this because plugging using the low quality low poly version the proxy geometry for the RBG simulation it will be more cost efficient to the simulation plucking this high quality gentleman tree into the simulation does not benefit us and in fact it makes the simulation a lot slower because there's more points to process the lower quality version is very close representation of the high quality one without the cost long cooking times this is a performance saving technique that the RBD tools use within its workflow however this isn't new in dudeney proxy geometry has always been used in simulations in a previous video of mine where I demonstrate how to set up flip simulations and how to deal with complex collisions I use a proxy geometry to help improve the accuracy of the simulation now the RBD bullets all there is the geometry the constraint geometry proxy geometry collision geometry if so if you have an animation which we're going to add a really simple animation that will knock part of this this solver to effect to destroy maybe a ball hitting at this wall this is where you would put it plug it in here v plug would be the guide simulation which will be discussed in a different video because that's a little bit more complex it's basically external forces that will influence the simulation and how it break now let's plug in what we know let's play in the geometry the constraints proxy geometry now if we just run it as is it just falls down because there's nothing to collide with let's add a ground so in the RBD bullets our solver bullet object collisions ground so this is where we put the ground put the ground plane it's right there now enforces it already comes with gravity so that's very handy we can just play it right now don't let's take a look at this error that we're getting I do not have constraints I did not define constraints because in the RBD metier fracture constraints I turned this off so I wanted to define it a little later the problem is this RBD bullets are when you come to solver constraints Bree King thresholds it's trying to find something to break it's trying to find a constraint break and it's trying to find these constraints which it I have not so it's not working properly now let's define some constraints or BD constraints there's a few ways you can define it this is the most simplest way it's actually this exact same way as the RBT material fracture set off the UI is almost identical there's you can convert curves so you can manually put down curves to drive the RBT constraints you can put lines you can have rules but I'm going to use a simple version of the RBD constraint properties I'm gonna throw this down well this here so this are really concerned now this UI will look very similar to what we had here to this part of the UI it's almost identical so I'm gonna put it here you can you can define it here you can just click check this and just define it here if you wish I just want to show you a different way of doing it our BD constraint properties here glue now this is ten thousand this way too much I'm just gonna lower this a thousand now I want to see my concerns we can actually color I'm going to give it come over here press W to go into wireframe own and you'll see your constraints because it's inside the geometry now lets me try the RBD solver let's replay it take a look what the render looks like let's pick a different frame now if you look carefully this part is not shattered this part we can see that it's shattered so we can see that this part which is this part is not it is is shattered no this middle part is intact the spiderweb the origin of the spiderweb is intact but we're still rendering the crack that's not very useful because it looks like it's already cracked before it's even collided with anything before it's even broken so the idea is to use this RVD connected faces and RBD disconnected face it to delete the connected ones to delete the geometry these lines the interior lines so they don't render but we want to render them when they are actually broken like for these pieces over here we want this to stay now that's how we're gonna use this RBD connected faces in rbg disconnected now what the RBD connected faces thus this only creates these attributes it doesn't change the geometry now we want to create the attributes Oh actually sir I shouldn't keep this here I should create a copy of this because I'm going to release this file up so I want you to have this for reference so I want you to have this side for reference I'm just gonna stick it here this doesn't have to be black anymore so this let's give it all right this is our BD connector faces only creates these primitive attributes what it does tell us is how close they are this is sort of like the rest length how close they're supposed to be and when we put this down so after this the solver the RVD bullet solver does not change these primitives so the RBD bolts on let's go to the primitives prim test this list should not change let's check out okay face ID to three to five it's point zero three two four six eight three let's go to a different frame face ID two three to five prim dust 0.03 two four six eight three face the ideas so it hasn't changed throughout the whole timeline this prim distance is not changing it's real like the rustling what is the original resting position so we know what's the distance between each piece before the glass is broken when it's a perfect glass now we can throw on the RBD disconnected faces so this is what we need here and we're gonna connect this to the geometry change the color to red by using it this here we're gonna delete the connected pieces so we're gonna delete these lines these lines are gonna go away in the render view if they are not broken so the ones like these ones this one here let's take a better frame okay these ones here they're actually broken they're disconnected so then we want to keep those faces so let's put the render flag here now let's go to the render view hit this this is disappeared now you you still see it in 3d viewport because this is the outside view now let me you don't see it in the render view so this is a 3d viewpoint we're both it's both the same frames frame 75 now these pieces here the key is these pieces these fractured pieces they still have the face they still have their face here go back here go here and I'm going to show you something and I'm gonna show you that it's actually disconnected there's actually its lead at the interior pieces then tear your primitives are deleted do is I don't exploded yeah yeah this is probably easier I'm gonna explode it very little go so this is non exploded so everything is intact so this part is rendering not this part I want to show you that these parts that this this larger piece that's intact does not have interior sots I'm going to slowly increase this okay so we can already see this so this is separate separated islands there is no in interior sites to this which allows the rendering to look to give it this solid piece look because there's nothing in the middle that's refracting the light that is how you use our BD connected faces so this is only for debug purposes now I'm gonna add an RB t io so our BD tools comes with its own file capture this is identical to the file caching that we normally see like this this is identical to that except because our BD tools has multiple inputs and multiple outputs this RBD IO is very handy because all you have to do is hook these up these up in the correct order geometry constraints proxy geometry and simulation points so this it goes in the same order as this one hook this up and this UI should look very familiar to you except for this is the only difference between the file cache the normal regular file cache and the RBI oh this will store everything packed geometry constraints proxy everything this will only store the junction but maybe you want to save yourself a few megabytes so you just want to store this you only want to file cache the high quality geometry then you can select this this will record the juncture and the simulation point I would prefer if you're gonna file cache it because the constraints in the proxy it's not as big it's not as that big I mean it's rather than re cooking everything re cooking the whole simulation so I would always use the middle one check the load from disk I usually take out the hip name only because I have multiple hip files so this makes it easier for me to swap hip files now be aware that this RBD i/o is very similar so I'm gonna connect this to the RBG disconnect to face it first so after you save it so you want to save all the simulation data here and then attach the RPG disconnected faces here because removing faces like all this is doing is delete connect it this is just leading stuff the leading stuff is very quick to do if you put the RB di all after the RB g disconnected faces here now this you lose a lot of data you lose all the constraints you lose the simulation points and our proxy geometry so you lose a lot of data you're gonna if you have anything else you want to might think of something you want to change the simulation on like add an attribute wrangle after to this then you'll have to recoup it because you don't have the constraint information so modifying anything else would make it a little more difficult so that's why the advantage of putting this node let's just connect this this note up here no I'm just going to delete this RB d hovering the mouse over here to get it all connected and you connect this if you want connect this over here and again I like to delete this check this and you can hit the save to disk button now this RBG i/o is is like having four file caches but it's just hooked up to the geometry constraint proxy and simulation points so this one our VDI own note is like equivalent to having four file caches the functionality is very similar the art BD connected faces and our be disconnected faces nodes are extremely handy for rendering transparent materials but I also think this would be handy for 3d printing 3d printers use applications like slicers to digitally slice the model into hundreds of horizontal layers that the 3d printer will then print each layer one at a time if we use both our BD face nodes to delete the interior faces it will create a more smoother model ready to be 3d printed as a and as a bonus the slicer would be able to parse the file more quickly as well because there are less polygons you could always use a boolean node instead to weld all the pieces together but sometimes if you have a lot of fractured pieces the boolean node could take a while using both our BD face nodes you can quickly and easily remove the interior primitives and save it as a STL file that's ready to be 3d printed thank you for watching and sticking to the end

Channel: bubble pins

Views: 9,585

Rating: 4.9663863 out of 5

Keywords: houdini, sidefx, destruction, rigid body dynamic, glass geometry, interior faces, 3d printing, rendering glass, redshift render, primdist, glass reflections, glass refractions, refraction, proxy geometry, cracks, glass cracks, cracking glass, houdini glass, houdini redshift, houdini transparent material, houdini interior detail, houdini rbd connected faces, houdini render, houdini glass shatter, houdini glass material, houdini tutorial, houdini beginner, houdini rbd

Id: oG8bSl83GAs

Length: 28min 40sec (1720 seconds)

Published: Mon Jan 20 2020