Bloom / Glare effect problem with mask

[L_ARSENAL]

Hello

I'm looking to get the Bloom/Glare effect on a specific material.
To do this i use the Material ID and the Material ID mask for the Bloom and Glare effect.

I have some issues for finding the good number for the mask of the material ID...
All my material have black material ID except the one i want to get the mask.


I looked on the internet to find some help but i only find results for 3Dmax... not good for Rhino...
Sometimes i manage to have the good result but i have to try many Material ID numbers on the Lens Effect panel, which is not the good way...
Does anyone knows how to make this work ?

Thanks for helping me
3HUIT