# Automatic Poly Mtl ID for Face ID in Multisub and UVWRandomizer **URL:** \ **Category:** Requests\ **Tags:** materials, maps\ **Created:** [August 19, 2025, 10:28pm UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705 "2025-08-19T22:28:53Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ChuckRT](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/chuckrt/32/48805_2.png) [@ChuckRT](https://forums.chaos.com/u/ChuckRT)\ **Post date:** [August 19, 2025, 10:28pm UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/1 "2025-08-19T22:28:53Z")
In order to use FaceID and Face MtlID in Multisub and UVWRandomizer maps we need to assign polys Mtl Id manually, right now the only way is to use Scripts, Could we have an automatic MtlID assign for poly, similar to Coronas behaivior? * * * _Submitted on AHA Ideas (VRAYMAX-I-145)._ ---
**Author:** ![dimitar\_panayotov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/dimitar_panayotov/32/36356_2.png) [@dimitar\_panayotov](https://forums.chaos.com/u/dimitar_panayotov)\ **Post date:** [October 31, 2025, 12:00am UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/2 "2025-10-31T00:00:00Z")
HI Carlos, can you show the Corona behavior and exactly what you would like to see? * * * _Submitted on AHA Ideas._ ---
**Author:** ![ChuckRT](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/chuckrt/32/48805_2.png) [@ChuckRT](https://forums.chaos.com/u/ChuckRT)\ **Post date:** [October 31, 2025, 12:00am UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/3 "2025-10-31T00:00:00Z")
Hi Dimitar Im sharing Coronas behaivior when using their MapRandomizer and Multisubtex in Polygon mode, as you will see, theres no need to asign material ids to polys in order to have randomization. Meanwhile in Vray you need to asign materialids to polys in order to have randomization, I can use scripts to do that for me, but if you can autoasing them like Corona it will be very practical. Hope the videos make sense. * * * _Submitted on AHA Ideas._ ---
**Author:** ![ChuckRT](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/chuckrt/32/48805_2.png) [@ChuckRT](https://forums.chaos.com/u/ChuckRT)\ **Post date:** [October 31, 2025, 12:00am UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/4 "2025-10-31T00:00:00Z")
I have to mention that Corona also auto assigns object Id and material id for masking. In V-Ray we need to assign them manually too, I dont care too much for that because of Cryptomatte 😀but maibe some people will be interested in those masks * * * _Submitted on AHA Ideas._ ---
**Author:** ![dimitar\_panayotov](https://dub1.discourse-cdn.com/chaosprd/user_avatar/forums.chaos.com/dimitar_panayotov/32/36356_2.png) [@dimitar\_panayotov](https://forums.chaos.com/u/dimitar_panayotov)\ **Post date:** [November 1, 2025, 12:00am UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/5 "2025-11-01T00:00:00Z")
Ok, I will check further on Monday. Thank you for sharing the examples * * * _Submitted on AHA Ideas._ ---
**Author:** ![AHA\_Migration](https://avatars.discourse-cdn.com/v4/letter/a/dfb087/32.png) [@AHA\_Migration](https://forums.chaos.com/u/AHA_Migration)\ **Post date:** [November 1, 2025, 12:00am UTC](https://forums.chaos.com/t/automatic-poly-mtl-id-for-face-id-in-multisub-and-uvwrandomizer/188705/6 "2025-11-01T00:00:01Z")
_AHA Ideas status: New._ _Set during AHA Ideas to Discourse migration._