I’ve read planar reflection , screen-space reflection , cubemap reflection . But I wonder what’s the reason we don’t reflect things by setting roughness to 0 ? I did it and found only when camera is lowered down to the surface it reflects environment , but vertical viewing shows surface black , as if fresnel . What type of reflection roughness is using causing this fact ? And can we remove the black mask ?
How do you mean, you’ve read?
The reason we don’t set reflective surfaces to 0 roughness, you mean? Well, from a workflow perspective, we don’t have anything perfectly specular because that’s impossible. Even very shiny shiny things are still a bit diffuse, because there is always imperfections in a surface in a PBR workflow.
If you’re having technical troubles, could you post the photos of your issue?
Hmm I mean there’s three methods to reflect things , but why need us to learn them instead of just setting roughness to 0 ? Though I’m certain I know the answer now .
The trouble I met . Half of the surface reflects nothing
There are more than three ways to generate reflections in unreal engine; to my knowledge there are:
- Cubemaps (including parallax-corrected).
- Screen-space reflection.
- Planar reflection.
- Distance-field specular occlusion (part of DFAO, sort of a reflection).
- Standalone RT reflections.
- Lumen reflections (software or hardware).
- Path-traced lighting (reflections and everything else).
In particular, the last three will solve your problem I believe.
Setting the roughness of what to 0? How does changing the roughness of a material affect the methods that are used to light it?
Do you have much experience in game engines?
Sorry . I mean , I like to make mirror by setting roughtness to 0 , but it was bugged . So I’ve read more about reflection , and found some other methods . I wonder what method '0 roughness mirrors use to reflect things , which caused the bug I’d met .
In real time you can’t have a fully reflective “render” like effect, you could set roughness to 0 and metal to 1 and use a reflection sphere, it’s the best option. Other you should tinker with a camera trick.