I have a question. I am thinking about getting Houdini Indie but the only thing stopping me is me being unsure of how and if vfx and animation files can be imported from Houdini into Unreal Engine 5. I can't seem to find an answer anywhere, just how to import static meshes, not vfx and animations. Not planning on making static meshes in Houdini since we use Blender for that, just the vfx portion really, and some animation since Niagara in UE5 has its limitations on what it can do, and in Blender they look unrealistic.

Oh, and also a side question: How would you go about saving these files to put on a website?

Any help would be much appreciated so that I can make a decision if I want to purchase it or not.

Primary question:
Is there any way of setting the usdprimtype to something other than "Points" while still allowing the attributes to import as if it were set to "Points"?

Context:
I'm playing around with editing a SkelAnimation prim from SOPs and I'd like to be able to override the translations, rotations and scales attributes.

I can get the translations attribute to override correctly with the usdprimtype unset or set to "Points", however once I set the usdprimtype to "SkelAnimation" the translations attribute only contains the first element (i.e. it goes from to ).

The alternative is to alter the attributes in python, which I've tested and works fine, however it would be such a convenient workflow to be able to simply tweak your SkelAnimation in a SOP Modify.

I don't exactly know what changed in between but at one point using the rbd to fbx and hooking it to the Null node named Export in the image worked, however after adding the breach frame collision and an assemble node, the node gives me a 30kb file which when I import it to Maya, gives me an empty group called "COPY".

merge node on the right has a warning saying "A mis-match of attributes on the inputs was detected. Some attribute values may not be initialized to expected values, e.g.: fbx_translation, fbx_scale, fbx_rotation, shop_materialpath, currentUVSet, ... "

and the bullet solver says "collision_object - /obj/Door_Sim/rbdbulletsolver1/dopnet/bulletrbdsolver1/bulletrbdsolver: Object contains duplicate values for the 'name' point attribute. "

However, the sim works perfectly fine, and the rbd to fbx node still doesn't work even if I bypass the bullet solver and use the node.

Any input would be much appreciated.

Thank you

Hi.
I have an HDA that is supposed to export stuff on disk using a button with a callback to the pythonmodule.
I need the button so the export is not automatic when instanciating the node, and I need to visually check the result before I decide to export. Much like a ROP node.
Therefore, the exporting part of the graph (a python node) is not connected to the Output and is instead a separate part of the graph that the PythonModule forces to cook like in the screenshot. It works thanks to marking the DIRTY and COOK nodes as editable in the HDA.
Now, this works well and all, and I've been doing that on many HDAs as a means to an end.

But now I have to put these HDAs inside another "Main" HDA that also has an "export" button to trigger multiple smaller exporters, and suddenly nothing works; telling me I have a something like a permission error for modifying nodes that are not editable. But they are. So it looks like this "editable" flag is not recursive or something ? What am I missing ? Do you know other ways ?

Has anyone else encountered this error exporting vertex_animation_textures?


Error
Error rendering child: /out/vertex_animation_textures1/render_position_and_packed_pscale/render_position_and_packed_pscale

I'm trying to export a simple particle sim to Unity.

Thanks

T

Hello.
I have usd files with geoometry and materials already assigned to the geometry. I need to go over primitives and make them into variants. I use For Each, and I got geometry variants, but my material siigment and mateial doesn't saved on geometry. How can I to bring materials back? And also materials need to be stored under new path (assets/conuese/mtl). As I have many files that need to be proceeds this way,it needs to be procedular ( I assume i will use TOP for this)

Hello guys! I'm having a problem, I'm rendering my character using aces (houdini envs, ocio on the color tab all that thing installed), on the mplay the color is ok! but when I save the file is all over the place

I tried the conversion on a cop network, but I can't get the same look as the houdini viewport/mplay


Ps: the second image is compreesed because it is a old render

Hi, how can I make custom emission just for yellow range color? for Arnold Render

pythonでstageコンテキストのmaterial library ノードの中にkarma materialx subnetノードをつくるにはどうしたらいいですか？
createNodeの引数の"node_type_name"にsubnetと入力しても、別のsubnetノードが生成されてしまいます。

sidefxに問い合わせたところ、
Yes it should be possible. The tab tool is defined in $SHS/toolbar/ExtraTools.shelf', which is calling createMaskedMtlXSubnet in voptoolutils.
It's intended to be called from the tab menu or shelf tool, so you may need to copy createMaskedMtlXSubnet() and adapt it to your specific script/needs.
との回答を頂きましたが、houdiniにもpythonにも初心者なため、まだ解決方法わかっていない状況です。
どなたか教えて頂けませんでしょうか？

Is it possible to use functions defined in a .py file loaded into an Extra files section in callbacks(of a button of an hda)? So far I did not manage to understand a proper way how to do it. I tried some dead ends like accessing the file through PythonModule in scripts tab but so far it seems to be a wrong approach.

Another question is regarding the possibility of the "OnCreated.py" script to modify other scripts like "PythonModule.py". I dont think it is possible. From what I understood it doesn't have the capability to modify the Python script associated with the operator type itself. I would like to confirm this thought.

Thanks for answers.

I want to create a Subnetwork which can get data from selected geometry on the Scene View.

Just like the node "Split":
1、Select the geometry on the viewport
2、Press down "TAB" and open the TAB menu
3、Type in "Split", and "Enter".
4、Then,the Split node is created and its parameter Group is the parameter I just selected.

Is there any way to get data from selected geometry on the viewport, and automatically fill in the params?

Hello,
I'm getting a camera mismatch issue inside Houdini. We export USD and alembic cameras from Maya and we are having problems with both cache types. 

When using an alembic camera (alembic archive node), I cant see the Arnold tab that allows tweaking of Arnold parameters, and with USD most of the time aperture value does not match with Maya original camera and we have to modify it by checking the values in Maya.
Are these known issues ? Are there any workarounds.

Appreciate your help.

b

We are in a situation where we have a SOP HDA, say foo.hda, that exists without any versions. However that same foo.hda exists in our HOUDINI_OTLSCAN_PATH in a lower priority path location where it happens to have a foo.hda::2 version which is significantly different from the foo.hda definition in the priority scan path location. As a result whenever we TAB create this SOP HDA in a houdini session using this HOUDIN_OTLSCAN_PATH we get the foo.hda::2 defined in the lower priority location... And if we then switch the asset definition to the foo.hda version it does appear to switch to the priority source location for the .hda file, however it continues to display the parameter interface that was defined in the foo.hda::2 definition which makes things very confusing.

Is there any way to get houdini to correctly resolve to the foo.hda definition (including parameter interface) that is defined in the first folder of the HOUDINI_OTLSCAN_PATH?

pythonでstageコンテキストのmaterial library ノードの中にkarma materialx subnetノードをつくるにはどうしたらいいですか？
createNodeの引数の"node_type_name"にsubnetと入力しても、別のsubnetノードが生成されてしまいます。

sidefxに問い合わせたところ、
Yes it should be possible. The tab tool is defined in $SHS/toolbar/ExtraTools.shelf', which is calling createMaskedMtlXSubnet in voptoolutils.

It's intended to be called from the tab menu or shelf tool, so you may need to copy createMaskedMtlXSubnet() and adapt it to your specific script/needs.
との回答を頂きましたが、houdiniにもpythonにも初心者なため、まだ解決方法わかっていない状況です。
どなたか教えて頂けませんでしょうか？

Hi,
I'm trying to put together a small project with friends, but I hit an issue because we want to use some of the neat features in UE 5.3, but I bought Houdini on Steam and the daily builds on Steam aren't really daily, it only goes up to 19.5.716, but I need 19.5.737 or above to get compatibility with the Houdini Engine for UE 5.3.

It would help a lot if someone could slap one of the more recent daily builds 19.5.737 or above on Houdini Steam?

Is it possible to somehow check fbx exporter code for Houdini? Or it's completely closed?
I've found an issue and can't resolve it (issue itself described here [www.sidefx.com]). So I'm looking for a way to check either `rop_fbxcharacteroutput` or `out/filmboxfbx` nodes source code to figure if it's actually possible to export normals for shape keys by some way or it just wasn't implemented.

Hi there,

I am a new Houdini user trying to build the 'SOP_Star' plugin. I have followed the instructions on this page [www.sidefx.com], but I keep getting this error when I run the 'hcustom' command:

error: unable to open output file 'SOP_Star.o': 'Permission denied'
1 error generated.
ERROR: Got error code 1 running '"`xcrun --find clang++`" -DUT_DSO_TAGINFO='"3262197cbf015d1133ae0c864e3f82e82e42cff5dd02cab036e695595943e49f369c35d2917e287a4358b3b64db97e511ba7b955abc2b60a49163d8f32ae81df1eee45b2ef925884b937981252ab11eebb5cc6dacfa2d924b3f61d585708b816bb1ef6549a22e135cdcfa8bbf35f3d06ce7c1f"' -DVERSION=\"19.5.716\" -DUSE_PYTHON3=1 -D_GNU_SOURCE -DMBSD -DMBSD_COCOA -arch arm64 -DAR .... error continues.

This is my current compile process:

1. Open the Houdini development terminal from the utilities folder.
2. cd into the SOP_Star folder
3. run hcustom SOP_Star.C
I haven't been able to find any tutorials / information on how to do this, specifically with MacOS, so any help would be appreciated! Thank you in advance for your assistance.

Hi there,

I'm currently facing an issue with Houdini plug in for Unity : I'm not able to cook asynchronously my HDA in Unity.

What I understood, by reading doc and check all sources, including wrapper and C code.

- Houdini async cooking must be set up while we're initializing our session thanks to this hapi.initialize [www.sidefx.com].

By default, value is , that means we're using all core but 1.

- Synchronous cooking is just added on "top layer" by polling request cooking status in 'infinite loop' to Houdini engine server until cook is done (successfully or not) and lead to blocking behavior as intended in not async mode.

RequestCook with Async = true just return on update Houdini routine (from AssetUpdater), to let the core do others jobs, and not blocking on update Unity main thread.

- No matter what I do, the call (hAPI cook node doc [www.sidefx.com]) is a blocking call, even with session setup with async.

What I've done :
- Once session created from code (tried both Pipe or Socket) and connected, HDA loaded and input node setup, we're ready to cook. So, I call RequestCook (from HEU_HoudiniAsset.cs class in Unity plug in) with bAsync at true.
Result : Unity freeze until cook is done, and my HARS process in Mac OS X going up to 1536% usage.

Tried to tweak lead to no change. Absolute values, negative (like -4 to use less core, etc...)

My questions :
- Is cooking async have an issue with M1-M2 Mac system?

- Is HQueue required to get Async cooking working?

- Am I misunderstanding something about Unity plug in, and how Async/Sync cooking is implemented?

Thanks for your help!

Hi Everyone
How I can archive my files referenced by the project , and creates the compressed archive file .zip in the directory current working path.
Ex files inside in /geo /tex /render folder + file .hip

Hi, I have a crowd setup and a dopnet contains a crowd solver and bullet solver. I want agent to transform to ragdoll by trigger like a flood collision, and ragdoll agent flow with the wave.
Then I tested to plug pop force/advect nodes in bullet and crowd solvers. There are no error message but simulation seems to ignore those pop nodes.
There are another some Force nodes(green color) available to plug after solvers like a gravityForce node. However, functions are limited.
I even tried to add popSolver and sopSolver to multiSolver, but it did not work as we usually expected.

Question is ;
Do we have substitution of pop advect and pop force(for noise) ? Especially I wonder if I can import SOP level's volume vel field and/or point velocities to apply ragdoll agents, and also can we use mesh objects to limit force area?

Thanks for your assistances!!

PS) I found uniformForce node + noiseField behave like pop force. However, I am still looking for how to use a polygon mesh as force area mask, and how to import SDF/density/vel field to drive ragdolls.