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Houdini Tutorials
can someone explain to me what all the contexts in houdini mean?, i really like houdini but im stuck on learning these contexts which are crucial to learning houdini.

i looked around and watched some tutorials but i still don't understand it.
old_school
First thing, set your desktop to “Technical”. This gives you the folder view on the left hand side. A Houdini scene is actually composed of network folders and objects inside those networks. You can traverse these folders with the network pane.

Folders are associated with a network type. We have acronyms for the network types and the nodes inside these networks.

Object = Object type nodes in an Object type folder. These Object nodes allow you build transform constraint hierarchies. Geometry type Object nodes contain SOP nodes that construct and modify geometry that inherit any transforms at the object level.

SOPs = Surface OPerators or geometry nodes that are inside an object folder. These are used to construct and modify geometry. Any kind of geometry from polygons to volumes.

DOPs = Dynamic OPerators or simulation/solver nodes that are used to construct simulations. Simulations read in geometry from SOPs and passes this data in to the DOP solvers.

SHOP = SHading Operators are materials that represent a shader to apply to geometry. Some are hard coded with vex and others are folders that you can dive in to and modify the VOPs inside.

VOPs = Vector OPerators inside VOP network nodes are used for everything from building shaders to modifying geometry, volumes, pixels, and more.

VEX = Vector Expression Language. The code language used to write shaders. VOPs are wrappers around VEX code snippets.

CVEX = Context agnostic Vector Expression Language. This has replaced all the VEX specific contexts throughout Houdini. It is a generalized language that uses the same environment and functions anywhere inside Houdini.

COPs = Composite OPerators in composite type folders. Used in image compositing operations.

ROPs = Render OPerators in side ROP Output directories which are used to create render output dependency graphs for automating output of any type of data and for triggering external processes like rendering. Commonly used to generate sequences of geometry, simulation data and trigger Render tasks that generates sequences of images to disk.

CHOPs = CHannel OPerators used to create and modify any type of raw channel data from motion to audio and everything in between. Most users safely ignore the CHOP context, and so can you, for now. Put it on the “get to it later” list when learning Houdini. But definitely keep it on the list.



All these folder types and node types are clearly indicated inside the Tree View you get up by default with the Technical Desktop. I highly recommend anyone new to Houdini to get used to working with the Tree view as you can see everything in the scene without diving in and out all over the place.

What makes these acronyms so important is that you can communicate ideas much quicker without any ambiguity with your fellow Houdini co-workers. This is known as “Houdini Speak”.

We have stripped many acronyms from the docs but the fact that they still exist and get used all the time speaks volumes to their usefulness.

If you ever speak with me, I use acronyms full stop and expect to hear them right back. Just putting that out there.


-jeff
Houdini Tutorials
I appreciate your reply but this seems like something too technical for a non technical dude like me. It's a shame, I actually learned the basics of houdini and now it's all for nothing.
old_school
That's too bad then.

My intention wasn't to scare you off. Just answer your question. It's up to you to filter and pick out the minimal bit you need.

I just exposed to you everything that there is in Houdini because you asked about acronyms btw. To be blunt, most Houdini users know just a fraction of the tools and they do amazing production work. Master just a handful of nodes and techniques and leave the rest alone.

What is it that you are interested in btw?
Houdini Tutorials
jeff
That's too bad then.

My intention wasn't to scare you off. Just answer your question. It's up to you to filter and pick out the minimal bit you need.

I just exposed to you everything that there is in Houdini because you asked about acronyms btw. To be blunt, most Houdini users know just a fraction of the tools and they do amazing production work. Master just a handful of nodes and techniques and leave the rest alone.

What is it that you are interested in btw?

not your fault at all, you did exactly what i asked so thanks, and i really wanted to use houdini as a whole 3d package because after trying Maya and Blender, i really loved Houdini's style in everything it did plus very easy interface and the renders are absolutely amazing and realistic to an insane level.

but i wanted to specialize in its dynamics mostly since that's Houdini's strong point, but whenever i go to a tutorial about most of the things in Houdini, all i hear is

“we're going to using a sop solver” or “pop solver” or “pop node with a sop solver inside it” or something similar to that which totally throws me off because i don't even know what he is talking about.

plus even if i knew what a sop solver was for example, i still would not know how to use it or what other nodes are compatible with it.

I wouldn't mind at all learning every bit of this stuff, it's just i try too and i still don't understand it at all what the tutor is talking about, is there a source where it explains these functions in plain old english? or in simpler terms? i even tried a sample of the “magic of houdini” book and let me just say, information overload.

is houdini's procedural system similar to unreal engines node based blueprint system?
old_school
I am only familiar with blueprint at a basic level but the two are quite similar in that they use nodes to construct procedural set-ups.

Houdini differs in it's breadth of features and in it's deep geometry modification toolkit including multiple primitive types and volumes.


As for learning simulations in Houdini, depending on what you want to do, most straight forward simulations should be just that. Not having to involve SOP solvers or other advanced simulation techniques. Most simulations should have set-ups from the shelf and you just tweak the set-ups in place.

If you have specific questions about simulations, fire away on new threads and we'll try to help out and simplify approaches for everyone to learn from.


-jeff
goldfarb
the introductory tutorials here on the site, in addition to the documentation should get you past these initial difficulties
if you find something specific that confuses you then post it as a question here.
Houdini Tutorials
jeff
I am only familiar with blueprint at a basic level but the two are quite similar in that they use nodes to construct procedural set-ups.

Houdini differs in it's breadth of features and in it's deep geometry modification toolkit including multiple primitive types and volumes.


As for learning simulations in Houdini, depending on what you want to do, most straight forward simulations should be just that. Not having to involve SOP solvers or other advanced simulation techniques. Most simulations should have set-ups from the shelf and you just tweak the set-ups in place.

If you have specific questions about simulations, fire away on new threads and we'll try to help out and simplify approaches for everyone to learn from.


-jeff

was just asking because i can see myself being able to learn the unreal blueprint system with minimal problems even though i'm not a coder at all and i know i can learn it because i have been using the unreal engine for about 2 months now and i like houdini even more because it also has the procedural workflow which is great when mastered, i guess i should give this more time for it to sink in which i will do because i really really love houdini already and its only been a week haha

well thanks again for your help, it is much appreciated and if i got any questions ill make sure to come here
Maxime Bruneau-lavoie
Hey there! I'm new to houdini as well, and it's true that it all gets very confusing at first but you have to give yourself some time. Houdini is notoriously hard to wrap your head around.

My best suggestion is that you should take notes. For example you should write down the definition for VOP, SOP, DOP, etc. What “$” variables are, etc. All of that is helping me a lot. You should also check out this guy for tutorials:

https://vimeo.com/rohandalvi/videos [vimeo.com]

Hope this helps.
sundevildave
Jeff. I too am at the bottom of the learning curve but am extrememly motivated.

Would you say that “object” type nodes are foundation of the tree?

“These Object nodes allow you build transform constraint hierarchies.”

Did you mean build, transform, and constrain hierarchies? Or just what you said.

Thanks,
Dave
ragupasta
Just to add this here as well guys. Houdini comes with a very robust help system. Drop down a node in the scene that you don't understand and hit the “?” in the top right corner of the parameters pane. This will bring up the online documentation. Now the beauty of this is, after reading the information, right at the bottom there is usually scene files embedded there which will auto-load into Houdini with a simple click, and the scene files are dotted with lots of information of exactly what the node(s) are doing at one particular time. So you can read and interactively run an animation that may be in the file and what it is doing and when.

A very strong way of learning and couple that with the beginner tutorials here and the transition from beginner to intermediate will happen faster than you think.
Ros
jeff
First thing, set your desktop to “Technical”. This gives you the folder view on the left hand side. A Houdini scene is actually composed of network folders and objects inside those networks. You can traverse these folders with the network pane.

Folders are associated with a network type. We have acronyms for the network types and the nodes inside these networks.

Object = Object type nodes in an Object type folder. These Object nodes allow you build transform constraint hierarchies. Geometry type Object nodes contain SOP nodes that construct and modify geometry that inherit any transforms at the object level.

SOPs = Surface OPerators or geometry nodes that are inside an object folder. These are used to construct and modify geometry. Any kind of geometry from polygons to volumes.

DOPs = Dynamic OPerators or simulation/solver nodes that are used to construct simulations. Simulations read in geometry from SOPs and passes this data in to the DOP solvers.

SHOP = SHading Operators are materials that represent a shader to apply to geometry. Some are hard coded with vex and others are folders that you can dive in to and modify the VOPs inside.

VOPs = Vector OPerators inside VOP network nodes are used for everything from building shaders to modifying geometry, volumes, pixels, and more.

VEX = Vector Expression Language. The code language used to write shaders. VOPs are wrappers around VEX code snippets.

CVEX = Context agnostic Vector Expression Language. This has replaced all the VEX specific contexts throughout Houdini. It is a generalized language that uses the same environment and functions anywhere inside Houdini.

COPs = Composite OPerators in composite type folders. Used in image compositing operations.

ROPs = Render OPerators in side ROP Output directories which are used to create render output dependency graphs for automating output of any type of data and for triggering external processes like rendering. Commonly used to generate sequences of geometry, simulation data and trigger Render tasks that generates sequences of images to disk.

CHOPs = CHannel OPerators used to create and modify any type of raw channel data from motion to audio and everything in between. Most users safely ignore the CHOP context, and so can you, for now. Put it on the “get to it later” list when learning Houdini. But definitely keep it on the list.



All these folder types and node types are clearly indicated inside the Tree View you get up by default with the Technical Desktop. I highly recommend anyone new to Houdini to get used to working with the Tree view as you can see everything in the scene without diving in and out all over the place.

What makes these acronyms so important is that you can communicate ideas much quicker without any ambiguity with your fellow Houdini co-workers. This is known as “Houdini Speak”.

We have stripped many acronyms from the docs but the fact that they still exist and get used all the time speaks volumes to their usefulness.

If you ever speak with me, I use acronyms full stop and expect to hear them right back. Just putting that out there.


-jeff


Beautiful, POPs?
goldfarb
RosatoRosario
Beautiful, POPs?

Particle Operators…but they live in DOPs now.
envato.herbreathing
Ooooh! I started learning Houdini 2 days ago and also couldn't understand the meaning of -OP and I was very angry because there is no info about -OP letters in the docmentation. Now I am happy) Thank you for the answer. Jeff, your reply is good))
tamte
jeff
CVEX = Context agnostic Vector Expression Language. This has replaced all the VEX specific contexts throughout Houdini. It is a generalized language that uses the same environment and functions anywhere inside Houdini.
this would be great, however even if we don't count specific shading contexts (surface/displace/fog/light/shadow), it seems that even in H16, Vop Chop (therefore even the “new” Channel VOP/Wrangle and Transform Wrangle) and Vop Cop2 Filter/Generator have still not been replaced with CVEX
I'd definitely think that H16 was a great candidate for replacing old VOP Chop with CVEX version especially with the big plans of using it for constraints
simonschreibt
I'm always a little bit confused when the shortcuts (sop, vop, cop, …) are combined to for example “VOP Chop”. Is this because the Channels are basically filled with Vector data and that's why you call these networks “vector operators (for) channel operators”?
simonschreibt
This was just handed to me and I guess it might be useful for others as well:

http://mikelyndon.online/2017/02/07/learning-houdini-like-a-language/
mrmowgli
Ok, so I am trying to figure out what a TOP or a TOP Network is, it's not in the on online help from Houdini. Any ideas?
vusta
Task ?
tamte
mrmowgli
Ok, so I am trying to figure out what a TOP or a TOP Network is, it's not in the on online help from Houdini. Any ideas?
or is it?

https://www.sidefx.com/docs/houdini/ [www.sidefx.com]
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