Settings for void/hole in Painter?

guitarguy00

Hey guys, I'm trying to fake a void/hole in my personal project. I have a negative height value, full roughness value and pure black. However I am confused about whether to give it a 0 or 1 for the metallic value. My intuition is to naturally give it a non-metallic value as there is nothing metallic about it, however to me it seems to look more convincing when it is metallic??

This is with a metallic value of zero(Non-Metallic):

This is with a metallic value of 1(Metallic):


I have a very low-value blur on it also. What do you guys reckon? How do I get the most convincing void? Anything else I can do to make it more convincing? Thanks in advance.

Kanni3d

I'd go with the first option, because it's seemingly more safer and "accurate", and gives a similar result. Obviously the better option would to have added a bit of geometry for a physical indent to get some natural AO and such. Using a blur is a good call for the soft height and soft "ao" look.

Even though both versions of this detail is "pbr incorrect" and being forcibly "faked", I feel like a non metallic surface (paint) receiving this small detail of metallic with pure black is much worse out of PBR range than the first option of pure black non-metallic. What you're essentially doing is just trying to add in a very strong AO into your albedo.

Check how it looks in your renderers (both dots at next to eachother)

guitarguy00

Kanni3d said:

I'd go with the first option, because it's seemingly more safer and "accurate", and gives a similar result. Obviously the better option would to have added a bit of geometry for a physical indent to get some natural AO and such. Using a blur is a good call for the soft height and soft "ao" look.

Even though both versions of this detail is "pbr incorrect" and being forcibly "faked", I feel like a non metallic surface (paint) receiving this small detail of metallic with pure black is much worse out of PBR range than the first option of pure black non-metallic. What you're essentially doing is just trying to add in a very strong AO into your albedo.

Check how it looks in your renderers (both dots at next to eachother)

Thank you so much. I think you are right also. I think because the "metallic" option gives a darker black, the illusion looks more convincing but it definitely isn't accurate. I'll try the two different dots next to eachother and go from there but I can definitely live with the non-metallic version.

poopipe

making it metallic is risky - not all shaders support occlusion of specular highlights on metals so you could end up with a  shiny hole. 

your best bet is to make it pbr compliant black (i.e dark grey ) and then ensure that it's fully occluded in your AO and specular occlusion/cavity/whatever maps

guitarguy00

poopipe said:

making it metallic is risky - not all shaders support occlusion of specular highlights on metals so you could end up with a  shiny hole. 

your best bet is to make it pbr compliant black (i.e dark grey ) and then ensure that it's fully occluded in your AO and specular occlusion/cavity/whatever maps

Good observation, did not think of that at all. Thank you.