Hi everyone,

I am a lighting artist who has some Houdini experience in the lighting area. My career is split into two, where I work at large studios as a lighter and I also work on my own as a generalist. As a lighter I am fairly advanced level. As a generalist I consider myself weak in context of my lighting experience. I lately decided to learn Houdini “more”. By more I mean really dive deep into it. I also would like to buy a licence for myself and move my personal work completely on Houdini pipeline. But before I do this transition, I decided to ease in slowly and learn from its community. I am already on the tutorials. I realize that I already mastered the basic stuff but sometimes I still get stuck even in basics. I need your advices especially in terms of workflow. For example, I normally do my modeling either in Blender or Maya. I can not really answer this question on top of my head; Shoud I move my modeling workflow to Houdini too? I am not very confident about modeling in Houdini so I first need to find an answer to this question. In the meantime I would like to find an appropriate way to import my existing models from other packages. I see that there are a couple of ways like importing as an alembic cache, importing an fbx or importing as obj files. All these options confuse me a little bit in terms of the way I am used to work with. For example when I import obj files, the file node keeps the geometry inside houdini even if I delete the external file which I like. But the caveat is that I don't get the separate object pieces but instead I get single merged one. If I import as alembic cache, I have access to all separate pieces but then the file is external and I could not find a way to keep them embedded in Houdini without having a connection to the external alembic cache. This starting point is important for me so I need your advices in terms of establishing a good workflow to work with other modeling packages. I also would like to find out more about modeling in Houdini. I can see the strength of the procedural approach but I also find it very cluttery to have millions of nodes in a simple character model.
Any and every advice of yours will be very much appreciated. Thank you.

You can always lock a node if you don't want external dependencies, or, export and re-import it as a .bgeo

Personally I wouldn't bother starting your model in Houdini especially if you are already comfortable modeling in another software. Much of the benefit you get from procedural modeling is still available whether you started that model in Houdini or not. Having an external app to use alongside Houdini for modeling is *very* useful.

Unless you begin your model in Houdini, model geometry is usually external by default. This goes for obj, Alembic, and Houdini's own bgeo format. Your file sop references the model outside of your hip file. However, any of those files can be made to be “internal” to your scene by clicking the “lock” flag on your file sop (or any node downstream from it). This causes the node to hold all data instead of getting it from the preceding node (or disk), effectively making the data “internal” to that node, and your scene. However most Houdini users do not work like this in general and only do that if desired for a specific reason. This is more flexible than having the model exist only in the scene the way, say, Maya does. Operating on data, caching out the results as a bgeo seq and filing them back in, even multiple times along your network, is a standard Houdini workflow and is great for removing the overhead of a procedural network.

FBX files are external as well, but they have their lock flags on by default. I believe it's possible to have them maintain their reference to the external file.

Fantastic. Thank you very much for your replies.

You should get used to having external references. It's one of the reasons Houdini can be so fast. Instead of having a single 1gig+ file storing all of your geometry, you spread that out across multiple files and only load what you need. Your hip file will be extremely small that way.

Side note here: One side effect of locking nodes I've found is that in the unlikely case your Houdini session crashes, I've had the locked geometry gone from the file, and had to recook those nodes. If you delete the original file, but have your Houdini node locked, you could potentially lose work (you'll have to rely on backing up your scene more).

I agree with what others said. I would use Houdini for the other work, or for procedural models. Model in whatever app you feel most comfortable in, and export it to Alembic for use in Houdini.

There is also a menu item called “Render > Preflight scene” - this will allow you to review all of your file references before rendering and make sure your project file can be moved. This means making sure your references either use $HIP where your scene file is the center of attention or $JOB which sets a project directory the center of attention.

This feature was designed to support rendering to the Amazon cloud but can be helpful for local projects as well.

Fantastic, thank you very much. By the way, I would like to ask which forum topic would be most appropriate to ask these kinds of questions ? I wouldn't want to be frowned upon especially in such an elite community

I'm Maya user too ,
in my opinion , Houdini is a great and best software in VFX and Procedural modeling , But I believe Modeling a character or car or any static object (not procedural) in the other 3D packages is so simpler than Houdini (Of course you can modeling any things in the Houdini too).

Also scene layout/management and rendering in the Maya is so simpler , So I usually use Maya for non procedural modeling and environment rendering and I use Houdini for Effects and procedural modeling.
for example working with Arnold in Maya is simpler than Arnold in Houdini.
About rendering Volumetrics such as Smoke , Dust , Fire and Explosion , Mantra is really faster and better than Arnold , V-Ray and Mental Ray in Maya.

About your question for Referencing external files , when I jumped from Maya to the Houdini it was strenge for me too .
But after working with Houdini , I knew this is a great and perfect feature.
You can load your project very fast , because huge models doesn't save in the hip file.
Also you can edit or replace any model on the Old referenced model very easily even without any need to open Houdini.
you can share one model to different hip files too.

as Solitude and others said , you can lock your File SOP node for writing it's data inside of the hip file.
unfortunately this method can use only for static objects (not animated or sequenced objects like Alembic).




But don't worry , Because Houdini is great and really powerfull , you can do and build any things in the Houdini.
you can create a HDA for reading and locking each frame of the Alembic or sequenced obj files for saving them inside of the hip file.

:idea:

there is , I made a simple HDA for you , you can save any sequenced obj files (Alembic or *.bgeo or …) in your current hip file :wink:

Houdini is pretty like to programming languages , you can add and develop any additional nodes and tools that you need with minimum programming .

In the Maya you should usually use MEL and Python for making new tools , But you can create too many useful tools just with Houdini standard nodes and VEX :idea: