Houdini 18 - Python Projects - Creating a Generic Json Exporter

[@raychen4607]

It has been a long time waiting for your update！！

[@Sharksleepy]

Thanks for the perfect turotial !!!

[@Ramt33n]

this is invaluable, a great reference to comeback to! Out of curiosity, why is json is the platform of choice for storing data, and not python itself? Python is not bad as far human readablity goes either! Thanks so much Indie-Pixel!

[@wolfuardianeos1302]

perfect

[@ahahlex]

Niagara sop node can export hjson file (houdini json), easily readable like json file. You can choose your attributes, set your frame range etc...

[@IndiePixel3D]

Yeah you can use that to export to hjson, but if you're building a custom houdini pipeline it's best to roll your own json exporter. Plus using the Niagara node in houdini requires that you install the labs toolkit which creates a dependency that could easily bring your whole pipeline down if the labs nodes arent installed or version mis-matched...that all being said if you are working by yourself then sure you can use the Niagara exporter.

[@ahahlex]

@@IndiePixel3D yeah I totaly agree with you, first I wrote all your code which work perfectly but then I tried to execute this function on each frame... but as I am not very experienced with python I couldn't achieve it (I am sure it simple for you). I tried to use Script sop and execute 'press button' of the hda, with no success... and I remember that it was possible to export particle attributes in hjson using niagara sop, that I finally imported in matlab 👌 I learn a lot about python in houdini with your video, thanks !

[@IndiePixel3D]

@@ahahlex Ah nice! Yeah if you are doing particle stuff that node is definitely made for it. I should show how to export frame data with custom code, but if you got it all working id just stick with the Niagara node for sue. Your comment was great! I just wanted to make sure peeps know that the Labs nodes can cause issues when creating large pipelines for large teams. Ill put an animated json exporter on the list. Thanks Alexander! :-)

[@ahahlex]

@@IndiePixel3D I would be super interested to see a video on how to create a custom json importer because right now I am using CSV format to import data inside houdini which is not super efficient for large amount of data :/

[@IndiePixel3D]

@@ahahlex sure thing, I did one a little bit ago, but it's on my patreon page, I'll have to move it over to youtube.

[@kasali2739]

Thank you for tutorial. how to save frame number with position? want to parse json file later in three.js particle sim

[@Mitroiul]

Hey, great video! However, is there something more I need to do in order to use this HDA inside of Unity? I've got this HDA into Unity and nothing gets exported once I press to export, though the same HDA has no problem working when used from inside of Houdini. I have the same HDA graph, just changed the first nodes into an Object Merge so I can fetch different HDAs and terrains inside Unity and export JSON files for them.

[@michaelreda5884]

Thank you for this video. I usderstand and do this exporter, but I dont's know what I will do with this json data? what is the application?

[@IndiePixel3D]

Well, I use it to take point cloud data over to unreal and unity to place objects and foliage...when I dont want to use the houdini engine. That's one example.:)

[@YoloMonstaaa]

@@IndiePixel3D Thanks

[@milosgalovic5583]

i don't really understand why you made the "user_attrs = {}" variable? you didn't really call it..

[@IndiePixel3D]

I'd have to look at the code again.