What is this visual artefact?

[Cyan]

A guy I know asked about these pics he took and I didn't know what to respond. Does anyone know what is technical name of this effect that shows in the shadowed part of the cone? It seems to be in some games these days -the brilliant dots- but I am not sure what it is.

 

[jlippo]

Byproduct of Interleaved sample patterns.

In this case it looks like screen space reflections and ray directions are in 4x4 pixel pattern.
If there is bright object in one of those directions, it will be bright pixel.

This is used quite commonly on ssao as well.

 

[Cyan]

Byproduct of Interleaved sample patterns.

In this case it looks like screen space reflections and ray directions are in 4x4 pixel pattern.
If there is bright object in one of those directions, it will be bright pixel.

This is used quite commonly on ssao as well.

Thanks jlippo for your superb reply. Excellent. When I read it my mouth dropped open. Like....so...was it that? Very interesting. I passed your reply to him. Why is it so common these days? Low settings?

 

[jlippo]

Without dithering patterns you would get banding and it usually looks worse.
Of course as usual if you can sample something few hundred times artefacts will disappear. (And FPS becomes SPF.. )

Guerillas cloud system did similar trick to get decent speed.
http://www.guerrilla-games.com/publications.html