Hi Harald and everyone :grinteeth:

This question is a doozy - maybe it's easier than it seems, or maybe it's not possible at all. I'm trying to achieve the Depth of Field post processing effect that is used in Hollow Knight (where foreground and background gets blurred). I would like for my artist to be able to move sprites/spine animations on the Z-axis for this effect when setting up scenes.

Quick note on Hollow Knight - I've been doing as much googling/research as I can to figure out how they did their Depth of Field effect, and some people were saying that they may have just baked the blur into their graphics. But this doesn't seem to be the case, because there is a hack/mod for Hollow Knight that disables the DoF effect, which essentially renders the background as crisp and not blurred.

I'm testing things out with URP (normal URP pipeline, not the 2D Renderer), using the Spine/Sprite/Unlit shader with a perspective camera. I've looked at these two posts and believe I understand most of everything that is being discussed:
Sprite shader depth write
Post Processing with URP not working with Spine Assets

The first thing I'd like to figure out is if it's even theoretically possible for this to work in the configuration I need. My game is overhead view (https://perennialordergame.com/), and I haven't seen any other "2D" overhead view games with this sort of effect. Would I still be able to keep (or replace with an equivalent/custom setup) my sprite/spine rendering order - I use the Transparency Sort Mode along the Y axis. One thing that I read in a couple places is that the Transparent render queue "doesn't work" with DoF. Does that mean it is not possible at all, or that you'd have to have a special configuration to get it to work? I noticed that when I enable "Write to Depth" on the material using Spine/Sprite/Unlit, that it switches from Transparent render queue to AlphaTest. I looked up AlphaTest and it appears to be "geometry" based (aka can't customize its rendering order?).

Side note - for what it's worth, having this DoF feature would be somewhat of a game changer for our design process. Having the ability to have animated spine graphics blurred in the foreground/background would be amazing, so if getting this to work means using a specific configuration of render pipeline and any other custom stuff, I would be all for giving it a try, even if it means a lot of extra work. Thanks anyone for any help!! 🙂

Doing some more googling and found this - may or may not be related. I'm not quite at the 'testing' stage yet - still gathering info and trying to make sure I understand what is going on. I've worked solely in 2D, so this is sort of a combination of some of the stuff that usually happens in 3D (writing to depth) but combining it with 2D workflow. I feel like I understand the theory, but not the implementation yet if that makes sense :lol:

http://wiki.unity3d.com/index.php/AlphaVertexLitZ?_ga=2.240169729.303854272.1573781327-1576606752.1529746758