Question Object revealed by light

Hello,
I want to have an object revealed by a spotlight like here :

or here :

But these shader are not compatible with HDRP.
how can I adapt them ?
Thanks a lot !

 

I have found a simple solution :
- Create an HDRP Lit Material
- Surface Type > Transparent
- Base Map > your map or your color WITH 0 value for alpha
- Convert the texture with alpha as a greyscale map (with black as transparent)
- Mask Map > put this new texture
- Put Smoothness remapping and AO remapping to the lowest

Create your object
MeshRender>additional Settings >rendering Layer Mask > choose a specific layer

Create the light which reveals your object
Light>General>Light Layer > add the layer of your object

 

can you explain a little more how do it