Introduction to HDA (Houdini Digital Asset) in Unreal Engine UE4 & Houdini for Beginners
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- Опубліковано 21 сер 2024
- HDA is an incredibly powerful tool. It will bring all of Houdini's power into another compatible 3D software, like Unreal Engine. This way you can utilize Houdini's attributes to setup materials and functionality in Unreal Engine.
In this tutorial, I demonstrate the very basics of HDA (Houdini Digital Asset), showing you how to create HDA to how you can utilize the HDA in UE4.
#houdini
#sidefx
#unrealengine
I forgot to explain why I deleted the "uv" & "shop_materialpath" attributes. I will explain that in the next video.
as I know you
your tutorials are so distinguished through internet
Really big thanks for you Mrs.
Thanks so much for the lovely comment!
Thanks. Can't wait to see the vertex animation tutorial in HDA for Unreal
Yes and there has been some new updates from Houdini for UE plugins! I can't wait until I get to this tutorial!
thank you so much for showing how to do the collisions, believe it or not,
this is the only video i found explaining it !!
Thanks for watching! I didn't know I was the only that touched on this topic. I've been trying to find time to make another video on defining custom collision geometry for UE hda.
@@bubblepins can you show how to use the materials on HDAs, from shop_materialpath, i'm trying to figure it out, but i can't understand peoples explanations,
i have some gltf models, with textures, i synced houdini with unreal, i applied what you showed in the video, i made the collisions, but i dunno how to export the textures. if you could help me, add me on discord IdirFETT#6735
I'm starting to learn about HDAs into UE4, thank you very much !
Awesome!
This is an excellent overview. thanks!
This was very useful. Thank you so much!
Thanks for the wonderful comment!
This helped thanks
Thanks for watching! I'm happy it helped!
your voice is so gorgeous
Thanks for the generous comment!
@@bubblepins You are doing great, I think you can be a bit more confident. I hear a bit uncertainty in your presentation.
@@ChaojianZhang Yeah sometimes. Thanks!
insane, lovely sounds
simp
Thanks Bubble Pins for the tutorial! I've been trying to replicate what you did with the collision, but as soon as I put anything in a group called collision_geo everything becomes invisible even the things that are not in that group. The solution I found to this problem is to make a subnet and put two geo inside it one for the model and the other for the collision and make the subnet an HDA. You later added (rendered_collision_geo) on top of (collision_geo) so you ended up with 2 collision geometries on top of each other. There are other ways to assign materials to specific objects in an HDA. Again thanks for the video, this took me a little while to figure out and your video was helpful :)
Thanks for watching! If you add a "collision_geo" group without "rendered_collision_geo" it will make it invisible. Only "rendered_collision_geo" will make it visible, it defines what will be rendered in UE.
I think if you don't have any groups, like zero groups, it will assume everything is "rendered_collision_geo", but as soon as you add "collision_geo", you need to define "rendered_collision_geo". I hope this helps! But I'm glad you still found a solution.
@@bubblepins I tried adding the other parts to a rendered_collsion_geo and everything was still invisible.
This is what one of the sidefx devs were saying:
If you're using complex collisions (collision_geo) then the collision mesh uses a separate mesh for the collisions, and can't be contained in the "main" static mesh.
Honestly I'm surprised how made it work, maybe it's because you selected the faces by hand or you have another version or something.
@@nodesofnature603 I didn't know that. I guess maybe because like you said, I selected through the 3D viewport. Sorry for misunderstand your last reply. My groups are primitive groups, not sure if that helps. This type of collision needs to be UseComplexAsSimple if you want to use simple collisions, I think you need to use the groups, collision_geo_simple and rendered_collision_geo_simple. I'll make my Houdini file available for download. But now that you mention it, I remember using HDA for UE4 a year ago (could be a longer than that) and it didn't work when I put it on the main, it did force me to put it onto a subnetwork. I wonder if it is a version thing. I'll try reinstalling a different Houdini version and see if I can reproduce this. Thanks for letting me know!
@@bubblepins When I use simple collision all my collision boxes merge into one big box which I don't want. Please you don't trouble yourself with this, unless you're doing it for your own curiosity.
@@nodesofnature603 Partly is for curiosity.
cool channel keep it up
Thanks!
Thank you!
I'd love to see a follow up to this going into detail about setting up parameters on HDAs that can be changed in UE4. I've been trying it this evening but find that none of the parameters I'm setting up come through into unreal. Not sure if they're things that aren't supported or I'm just doing it wrong!
yeah it's a bit tricky to set up, some parameters are supported, but some aren't. I was going to do another UE4 / Houdini tutorial, I've just been learning a bit more of the UE4 software. Hopefully I can do something soon.
In the mean time this documentation page may help you:
www.sidefx.com/docs/unreal/_attributes.html
@@bubblepins Yeah, I'm going to have another go tomorrow and see how it goes - cheers for the link. I been using UE4 a long time but Houdini only recently, so I'm looking for decent tutorials on that front. Either way, this channel is a really good resource - whatever you make is always appreciated. Keep up the great work!
@@eggZ663 I have been looking into starting a live stream Q&A for a future patreon campaign, as a way to create more casual tutorials faster, because the youtube videos take a long time to produce. Stay tuned for that if you're interested.
@@bubblepins I feel that would be a really good way of learning. A lot of the time you are looking for one small bit of info and you never know if it's going to be covered in a long format video tutorial :)
Is it possible to use Houdini geometry from outside the HDA, like from an object merge?
In other words, it would be as if you made that same HDA with Flippy and the 2 cylinders, EXCEPT they were not inside the HDA subnet.
I believe that you're trying to export just mesh geometry from houdini into ue. If I'm understanding this correctly, you can drop down a fbx rop node to export the geometry from houdini. Then just click and drag the fbx files into the content browser of ue
I hope that helps!
Yeah in essence, I am making a slightly better import process.
But since it involves many fractured pieces that may change in number, it helps to have a way to do it procedurally. Chaos fracturing ended up not having enough control.@@bubblepins
@@QuiteDan If you export the RBD pieces as packed primitives and overwrite the path in the FBX ROP node to match the RBD config path, you can just drop the RBD simulation into UE and it'll be a animation sequence. It's actually an animated rig underneath. I think in Houdini 19.5 they made an improvement that all RBD simulations before you unpack it, like coming straight out of the RBD solver, is an animated rig. You can actually modify it using MotionClips too, because of that.
Oh yes, I just discovered that today in fact!
I think I have a workflow down now. The plan actually was to sim inside UE, so only a good way to transfer fractured static meshes was needed@@bubblepins
@@QuiteDan The discovery sometimes feels like finding a hidden gem doesn't it? I was very excited when this feature came out!
Thanks a lot !
when i import it only shows houdini logo in ue4 : no parameters or any other 3d objects ( only houdini logo shoes)
This video is a bit old, there's a new plugin for Houdini to UE4, it's called Houdini Live Link. But you still should be able to see something load other than the logo. Can you double check if you enabled the Houdini plugin in UE4? Houdini Engine now comes with UE by default.
I did a more recent live stream on the live link tool:
ua-cam.com/video/05lCOcrNikU/v-deo.html
See if that would help you!
how to install houdini engine for unreal ? ( other than reinstalling it)
Up until Houdini 18, there's no way! lol at least that I know of. You literally have to reinstall the entire Houdini to get to that menu to prompt you to install UE4 plugin. I know, it's tedious... I had to do it a few times myself just because I selected the wrong version. Maybe that will change soon, because Epic Games is know an investor in SideFX so they are partners!
Hope that helps!
HOUDINI 18.508 SUPPRTS UNREAL 4.24 BUT FOR 4.26 YOU HAVE TO INSTALL LATEST HOUDINI DAILY BUILD NOT PRODUCTION BUILD
My mesh is not showing in unreal. It only shows as the houdini logo. :(
Is there a node that's cooking in the subnetworks? like hf erosion or a sop solver? Try putting a file cache node at the last node before the OUT null node.
I have the same problem. I'm wondering if it's because we are running on a Houdini Apprentice License and not the indie commercial license. ?
@@miximum1 I haven't tried this particular feature with Houdini Apprentice, but I don't think it works. There are a lot of export/import limitations with Apprentice. Here's a forum post I found googling, I hope it helps.
www.sidefx.com/forum/topic/62241/?page=1#post-276869
Do you know something about HoudiniNiagara plugin? Because im having some problems
I followed the video, everything looks fine in the viewport, but I could not save the level where it says Graph is linked to a private object in an external package. Does any of you guys have this issue before?
Well, I clicked bake and replace all Houdini assets in File Manuel to solved the problem. Not sure if that's the correct way to do it though
@@soliptionpictures7740 I'm not sure about the baking part, but If you Rebuild Asset it should work. But I dug up this in the documents:
"All Houdini assets present in the level can be replaced automatically by their baked counterpart by using the Bake And Replace All Houdini Assets entry in the file menu. This process cannot be reverted and should only be used with final content."
www.sidefx.com/docs/unreal/_assets.html#AssetsDetailsBake
See if that helps!
@@bubblepins Hi there. After several days I found it is the version of the Houdini engine that supports 4.26 that needs to be v2 instead of v1. So v1 will show the assets but nothing more. v2 has everything I need.
@@soliptionpictures7740 I'm glad you found the solution! Thanks for telling us so the next person will know!
i have one question when you use collision geo we cant see it but the shadows are there why so? is there any way to fix
I think the light maps in UE aren't updated, it sounds like something is using the out dated cache. Try rebaking the lightmap in UE.
Hello Buble pins , thanks for your video it's a very helpfull for understand how HDA work. BuT I have a big problem ... I don't know why but I cannot have the Houdini Engine plugging for Unreal . It's not activate even if I download the good files . Do you have any idea that can help me ? I'm on Houdini indie 18.0.499 and my version of unreal is 4;25.1 normally it should work
but not :/
I checked SideFX's repo logs and it says the latest Houdini version that has UE plugin support is:
Houdini 18.0.459 Added the Unreal 4.25 plugin. Wed. May 6, 2020
So I believe build 499 won't work with UE plugin.
In the video at 4:23, I show how you can check the logs on Houdini's website to see what's the latest feature implementation.
@@bubblepins ok i see. And how can you download a lower version of houdini because on their download page I don't find this version www.sidefx.com/download/daily-builds ? It the same case for the 18.0.316 :/
@@nicolasmotais1337 You can try version 18.0.459 it says "Added the Unreal 4.25 plugin." on the the comment.
www.sidefx.com/changelog/?journal=&categories=52&body=&version=&build_0=&build_1=&show_versions=on&show_compatibility=on&items_per_page=
When you install Houdini, the wizard installation you need to check the UE4 plugin option, this can only be activated on the installation step of Houdini, which is very inconvenient. Because if you miss this, you need to uninstall Houdini and reinstall it just to get the plugin.
Hope that helps!
Could you tell us what the point in Houdini is?
These are things that would be easier to do just by straight impoting and duplicating.
I used a very simple exercise in this video to demonstrate how to use the Houdini plugin for UE. One of Houdini's strengths is in its non-destructive proceduralism. I think this is something Houdini excels in. If you want to compare UE vs Houdini in an apples to apples level, I guess you could get similar results in UE with some clever blueprint coding, but it all depends on what you prefer for your workflow. For Houdini, its non-destructive workflow allows you to change an object at any point and in any form, just like github repositories, you can pull, modify, publish any project at any commit stage. Houdini can procedurally generate/modify any object you want at any step along the development stage, without even losing your original geometry shape. And Houdini's simulations are very powerful as well, that's something that UE is just starting to dip into with its relatively new Niagara particle system. But Houdini has had a particle system, pyro system, flip fluid, rbd, soft body, muscle, clothing, ... (& much more) .. systems dating back many years ago. Each system has evolved so much over the years and matured to a very reliable and usable system.
how to import particle simulation or pyro, flip, etc in unreal Engine?
thanks your video
I know you can convert a Houdini sim into a sprite animation that can play inside UE4, but then you don't have the collisions. I don't think you can use the UE4 plugin to do animation, it seems like its only for static meshes, but I could be wrong. I know there's a way to convert the flip fluid animated mesh to UE4 using vertex animation, but I'm still playing around with that. I did it in Blender to UE4 for some Blend Shape when I did character sculpting.
Let me play around with the Houdini to UE4 workflow a bit more and I'll do another video. I'm hoping to figure out the vertex animation part, then you can use the Houdini sim and still have collisions in UE4.
Please tell me I am wrong, you have a plugin for Houdini inside Unreal, to import static objects ? if that is the case then it is totally meaningless.
Houdini is very famous for their procedural workflows. You can create a lot of different models very easily using procedural modeling. If you wanted to model a whole bedroom, you can make the arrangement, alignment, size, position, and so on everything procedural and even use a wedge or python node to create hundreds of different bedrooms that will generate automatically. Handy for city building. This is something UE doesn't have, but Epic Games is getting very close to be honest. UE has this instance node in blueprints, but they are very far from what Houdini can still do.