Just as a side-note - We will be implementing glTF interactivity in the near future. Part of it is already in core, we are missing a few nodes and the actual extension to process the node graph.
It look like we’ll be working on Behavior Graphs for Hubs, and we’d like to harmonize with other work.
Are you implementing any nodes that aren’t in the spec? And do you have automated tests for graph validity?
Yep, I am working on that this and next week. I have a local branch on my babylon fork with some changes, spec updates and new nodes. I will submit a PR to track this branch by the end of the week.
And sorry, forgot to answer your second question - we have unit tests that are already integrated, and that will be expended over time. I am working on test JSONs, but I do hope that they will eventually officially come from Khronos. This is the current test data (partly modified data from this PR - Initial work merge by mattmacf98 · Pull Request #1 · KhronosGroup/glTF-InteractivityGraph-AuthoringTool (github.com)) Babylon.js/packages/dev/loaders/test/unit/Interactivity/testData.ts at master · BabylonJS/Babylon.js (github.com) Note that these are not updated to the latest specs, so use them with caution.
Hey, is there an ETA when the interactivity implementation in Babylon will be updated to the latest spec proposal?
Here’s some issues we found while testing:
- lifecycle/onStart should be event/onStart
- lifecycle/onTick should be event/onTick
- event/onSelect is missing (used in most test files)
- KHR_node_selectability is missing (event/onSelect is strictly speaking a part of that)
Thanks!
The latest specs are not the latest specs. They are a 4 months old draft. Being a part of the discussions regarding the specs I can say that changes are coming to this document as well.
I have the current specs implemented on a local branch - GitHub - RaananW/Babylon.js at gltfInteractivity
I am currently working on writing further tests, but I will not submit a PR until the proposal will be updated and I will update the specs, otherwise we will have a cat-and-mouse situation of us chasing changes again.
Regarding event/onSelect - it is not part of the current spec as well. This is a part of a different extension that will also be implemented as part of interactivity.
Thanks! Not sure if you’re aware, but I’m part of those discussions as well, thus me asking here 
It’s great that you mentioned your branch – is there a way to e.g. load the Sandbox from that branch? That might already be good enough for testing, as we’re starting implementation into UnityGLTF.
As mentioned, yes, event/onSelect is part of KHR_node_selectability. Are you planning to add that on your branch? Most useful/non-trivial test cases use event/onSelect to have something interactive, so being able to try that out would be appreciated.
Sorry! I didn’t recognize the username
Yes, selectability is already part of the branch. And now, this branch cannot be tested on the sandbox, but I can open a PR that will update the branch’s snapshot (which will allow that). Would actually be great if you could test it with me.
If you could open a draft PR and that produces a new sandbox link that would be cool! We’ve started actively working on this so lots of testing is happening.
Currently we’re alternating between the implementation in Babylon Sandbox and the separate Babylon KHR_interactivity implementation in GitHub - KhronosGroup/glTF-InteractivityGraph-AuthoringTool: A React based DCC for viewing and authoring KHR_interactivity models for testing.
Once this build is done - [DRAFT] glTF interactivity and flow graph update (For snapshot) by RaananW · Pull Request #15810 · BabylonJS/Babylon.js · GitHub the current version will be available to be tested on the sandbox. Could you share (ever privately) the test files you are using?
Just want to be sure that you know this is all WIP, so expect a few kinks and issues as I am actively testing it as well. I will keep the draft PR open to make sure the snapshots are updated. The latest block I added yesterday (for easing in interpolation) caused a few issues with the build, but it was resolved now.
Awesome, thank you! I’ll update here if we run into issues and/or what we find during testing.
Do you have any node implemented (like “ADBE/output_console_node”) that can be used to just log data to the console for testing?
yes, there is a “babylon/log” which takes a message. all test scenarios are using it
Hey, just wanted to say - github issue was updated (and will continue being updated.
I think I will keep the PR open so everyone can test whatever they want. Snapshots’ cache is not being purged constantly, so you might need a hard refresh to make sure you get the latest, if you want to test it.
Thank you!
Is there some kind of logging flag (a query parameter or so?) to have the execution model log some debugging steps?
(The “Logging Engine” of the Graph Authoring Tool does that, and it’s quite useful to not having to slap console nodes on everything when just trying to understand what’s happening when.)
Nope, not yet implemented. It’s on my list of future tasks, but there are a few things I want to do before that.
My idea was to make the graph (and context) “verbose” using a flag, so it outputs what it currently does (which I assume is similar to the logging engine). Not sure yet how this will be implemented though.
Hey @RaananW, I posted two failing files here ([DRAFT] glTF interactivity and flow graph update (For snapshot) by RaananW · Pull Request #15810 · BabylonJS/Babylon.js · GitHub) because I’m not yet allowed to upload attachments in the forum here.
Wrong colors?.. Probably parsing the color3 class incorrectly. I’ll check that, thanks for reporting.