Houdini Engine for Unreal | Instancing & Variation

hello in this video i want to show you about instancing in unreal with your dining engine in houdini java i already got a small setup so here i have a grid with also some scattering points and then i will copy a model on it so in this case the rubber toy so in the copy to point is something special and this is the first way of how i show instancing here so in there we're going to enable the setting back an instance so this is a method on how we can instance instead of making new unique geometry so next step is making a tool from this so i'm going to select everything you see here and i'm going to go to assets new digital asset and i'm now going to quickly make a tool from this then we bring this into unreal so we can import our tool here and now we can drag this into our scene so after a moment when it is done calculating we will see our model with also that material here and in real so the exact same result is here seen in unreal so here on the side we can see that we have outputs and then we have instances so we have our mesh ancestor and we also here have the geometry from that instant itself so now we can also like play around with that so in this case we have that rubber toy but sometimes you want something that's something in the project for example here a tree so i can grab the tree and drop it in that slot so now i have instanced that tree so we control the placement of the tree by the houdini tool so i can also add variation by clicking on the plus icon and i can for example now grab the other three the green one and now we have different trees on in the scene here so we have a few ways here to add some variation automatically so these are now a nice set of trees but i also want to show you another way of instancing so here we took the rubber toy and instant that on certain positions but i also want to directly access the trees so here i have these two trees i directly want to use them in my system so back in houdini what i'm going to do is i'm going to go to my tool that i made here and i'm only going to copy paste the parts with the grid and the scattering points so i'm going to copy paste that outside of the tool and i'm going to make like a new tool with attribute instancing so here we have our scattering points and on these points i want to add information on what model they should be instancing so i'm going to create an attribute and in that attribute i'm going to store that value so first of all we need to give the attribute the proper naming so the houdini engine will recognize it so we're going to use unreal instance and then here we need to fill in a pad so we need to change the type to a string so we can fill in a pad to the to the model to instance for the pad itself we're going to go to unreal right click and say copy reference so with that reference or path we can paste it into on into our attributes and with that setup we can now go to our geometry spreadsheet and you can see that each point has the information about which model it should be c which should use as instance so now let's test this out so we only have a few points here and now let's decide by making a new tool so a new tool instance attributes and we're going to import that into unreal here as well so now the same process we're going to drag the asset in our scene we have then our trees automatically assigned on the points that we had in houdini so here we can see that we also have an output instance so we have also that output there what is interesting to notice here is that with our copy to points method we had also that geometry also being generated because we used the geometry from houdini so here i'm going to quickly refer to settings so here we have the unique geometry generated as well where in my other tool we only have the instance because we don't need new geometry here we can also take blueprints or other unreal assets to instance so it's not limited to models we can also do for example like blueprints or particles as long as we can get a path to that to that asset so again here you could also press the plus icon and that variation but i want to show you another way of adding variation with attributes and in houdini we can actually control variation way better so here i'm going to take my other three the green tree and i'm going to grab the reference here and we're going to jump here into houdini and in here instead of using that at create attribute i actually want to create a random attribute so i want to randomly select the red red orange tree and the green tree so in that attribute randomizer we of course need to give it a name unreal instance and in there we want to make sure we are setting different string or path so we're going to go to custom discrete and under custom discrete we can change the type to a string value so now we have the option to then fill in the paths we had so here we can make as much models as we want to in this case i only have two so i'm gonna fill in two models here so we can fill in two pads i'm gonna copy paste them here so i will copy them and we're also gonna copy the previous one here and copy paste that in here as well so now these two are ready to go so i can bring in an output just to make sure that this is my output and not the other one so let's save that let's jump into unreal rebuild our asset and now we should see different trees or a variation in our trees so we have that orange and the green ones now with that setup i want to actually make a more custom menu to easily access these instances so i'm going to go to assets and edit a property of my asset so in here i'm going to go to parameters and we're going to create custom parameters or sliders that we could use inside of unreal so here i can for example grab for example the seat value of this randomness so every time i change that value we will have like randomly placement of the tree so if i go to options grab the seat value this will now be accessed in real so once i hit apply it's like fully linked to the tool so now also here we can grab for example the pad so the location and we can also grab the weight so the weight is interesting so if i increase the weight the model will be appearing more if i lower the weight it will be appearing less so now we can just grab for example the pads give it also a proper naming like model number one and we'll also grab the other one model number two and we can also grab here the weight value so we can change how much this model is appearing in my system so pressing apply and then they are linked together so now in unreal we're gonna hit rebuild again and now if everything goes right we will see we will see here our menu with our parameters so we can play around with for example the seed so we should see variations now when i change the seeds the trees are now on different positions every time i play around with that and we also then i hear our other parameters like the pad and also the weight so the weight if i increase the weight we will see more of this tree so the green one is now appearing more than the other one and then if i increase if i lower this or put this to zero we barely will see that reappearing so we can control a bit with some sliders where or how much they should be appearing now also we have this pad but we can also drag and drop actually our asset to that pad so if i just hold my mouse and drag an asset there i can automatically assign that there so here these are now the same colors so but you can just drag their assets in there so if you share the tool with your teammates or team members they can just drag in their custom assets and have them placed automatically by houdini so of course you can still use like the instance outputs but you can build a custom interface for that as well so of course you can now start expanding this menu so we can go back in our houdini setup for example i can expose the scale of my scatterer so we can go back in in real and now i have a scaling value and i can scale my trees up bigger or i can for example make them smaller and here is also then sort of like a small forest scene that you can quickly create by just scattering around trees and that was it for this video so i showed you two ways of interesting with the copy 2 points this is mainly useful when you want to bring a model from houdini inside of unreal so it will import that as well an instance for you but most of the time if you already have models blueprints things set up in unreal we want to use attribute instancing so we can directly say what models should be assigned to which position so artists don't have to figure it out they will automatically be set up for them so that's sort of like a bit of the difference between those two so most often attribute interesting is quite popular overall so that was it for this video i hope you learned something and thank you for watching

Channel: Houdini

Views: 17,865

Keywords:

Id: rPSzvHBl1zE

Length: 9min 54sec (594 seconds)

Published: Tue May 04 2021