EDIT: I missed one case in the video: when the prerendered bg is in front of the additive particles,
the particles sort in front of the prerend which is incorrect. The fix is very simple: just grab the custom depth emitted by the particles and compare it with the bg depth (this is after you turn on custom depth writing on them) imgur.com/w4AP4tK (Before: imgur.com/a/McY1NO7, After: imgur.com/a/sZP8oeY)
In this part 2 video, I show you how to fix the issues of additive/translucent materials not blending in with the prerendered setup from the previous video.
The technique uses the stencil buffer, opaque objects write a value of 1, while additive particles write a value of 2, values of 1 will use regular opaque blending (using standard scene-depth vs prerend-depth comparison), values of 2 will use additive blend (prerend-color + scene-color), overlapping values (1+2) will still use opaque blending. More on stencil can be found here: medium.com/unreal-engine-material-guides/overlapping-custom-depth-stencils-a084aa763f10 and ua-cam.com/video/PiQ_JLJKi0M/v-deo.html
Particles are from Marcis's Retro Particles: www.unrealengine.com/marketplace/en-US/product/retro-particles-lens-flares?sessionInvalidated=true
Models and background artwork is by @fleshinteractive
BG Music belongs to from Parasite Eve 2.
Timecodes
0:00 - Intro
0:45 - The Issue
1:38 - Disabling Some PS1 Settings
2:00 - Tweaking Material to Use Named Reroutes
4:55 - PreRend Material Refresher
5:40 - What We Need to Do
6:08 - Enabling the Stencil Buffer
8:40 - Using the Stencil Buffer
14:53 - It's getting there
16:16 - Using Stencil Write Mask
18:20 - That's it (It works)
19:11 - Transparency
20:46 - Using Masked instead, faking it
25:00 - Using CheckerPattern instead of DitherTemporalAA