# Relationship validation **URL:** \ **Category:** USD\ **Created:** [February 5, 2024, 9:50pm UTC](https://forum.aousd.org/t/relationship-validation/1209 "2024-02-05T21:50:45Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![dhruvgovil](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/dhruvgovil/32/3_2.png) [@dhruvgovil](https://forum.aousd.org/u/dhruvgovil)\ **Post date:** [February 5, 2024, 9:50pm UTC](https://forum.aousd.org/t/relationship-validation/1209/1 "2024-02-05T21:50:45Z")
Is there any form of validation for relationship attributes? And on that same note, even if USD itself doesn’t validate, is there a way to express the restrictions? II think the answer is no to both, but I just wanted to check in case I missed something. The kinds of restrictions I was thinking of are: 1. Type validation e.g I material binding should only point to Material prims etc… 2. Cycle checking to prevent cyclical relationships It would also be good to know what we do when a cycle is encountered. Is that purely up to the consuming app/render delegate? ---
**Author:** ![BigRoyNL](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/bigroynl/32/413_2.png) [@BigRoyNL](https://forum.aousd.org/u/BigRoyNL)\ **Post date:** [February 5, 2024, 10:38pm UTC](https://forum.aousd.org/t/relationship-validation/1209/2 "2024-02-05T22:38:59Z")
> [@dhruvgovil](#): > > Type validation e.g I material binding should only point to Material prims etc… Don’t have a clear answer, but… Isn’t it technically possible in USD to set up a binding to a material path that doesn’t actually exist? If so, at what level would you expect this type checking to occur? On the stage composing? I had seen e.g. Render Settings with Render Product relationships being able to map a relationship target even to a Render Product does not exist anymore. Also, I haven’t seen any typing around any `UsdRelationship` myself so I’m not sure if there’s even a registry that says they can only bind to material prims. (Aside of that, couldn’t they also bind to Collections?) ---
**Author:** ![dhruvgovil](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/dhruvgovil/32/3_2.png) [@dhruvgovil](https://forum.aousd.org/u/dhruvgovil)\ **Post date:** [February 5, 2024, 10:53pm UTC](https://forum.aousd.org/t/relationship-validation/1209/3 "2024-02-05T22:53:50Z")
Yeah I was thinking it wouldn’t necessarily be at author/write time but could be some kind of utility function or option on an attribute writer. So you could still author dangling ones, but check resolution at different times ---
**Author:** ![spiff](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/spiff/32/22_2.png) [@spiff](https://forum.aousd.org/u/spiff)\ **Post date:** [February 6, 2024, 12:44am UTC](https://forum.aousd.org/t/relationship-validation/1209/4 "2024-02-06T00:44:21Z")
Keep an eye out for our proposal on a general validation framework. We don’t want to generally do alot of validation within the core authoring code… and cycles aren’t _always_ a proscribed thing 🙂 though that one might make sense as a “general warning”… ---
**Author:** ![dhruvgovil](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/dhruvgovil/32/3_2.png) [@dhruvgovil](https://forum.aousd.org/u/dhruvgovil)\ **Post date:** [February 6, 2024, 2:12am UTC](https://forum.aousd.org/t/relationship-validation/1209/5 "2024-02-06T02:12:42Z")
Oh nice. Something to look forward to ---
**Author:** ![syoyo](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@syoyo](https://forum.aousd.org/u/syoyo)\ **Post date:** [February 6, 2024, 1:40pm UTC](https://forum.aousd.org/t/relationship-validation/1209/6 "2024-02-06T13:40:25Z")
For cyclic checking of attribute connection, TinyUSDZ Tydra records visited property paths to detect it: > Same can be applied to Relationship resolution. As @spiff pointed out, validation should be done in surrounding framework, not in core part.