I need to render the scene in the background look like a pecil drawn sketch, foreground objects needs look realistic. Is there any Material Node reference shaders or Addons to achieve this style?
Nothing about an AI generated reference is going to be consistent, realistic, or replicable. If you can share a reference of a real human drawing with a physical or digital pencil, I can help you replicate that look
I think they’re using a lot of 2D billboarded assets to further the illusion that it’s sketched, specifically the foliage.
Overall, that and the outlining are doing most of the heavy lifting to produce that effect. The rest is very simplified texturing. Fields of blotched colors that give the impression of a surface, but no more.
In several painting appls there are different filters aiming for some painterly, pencil- or handdrawn look. They all started years before AI. So if do not use this “for every frame” but instead on the used texture images itself… or back them and then use the filters then this might be a start.