Unreal 5.3 - The Jump Flood Algorithm (or how to make wide outlines!)

In this video I cover the basics of the Jump Flood Algorithm (JFA), and how to make the effect in Unreal Engine. This version uses a single Render Target, unlike other similar tutorials.
Ben Golus' Post on the subject: / the-quest-for-very-wid...
Shadertoy version: www.shadertoy.com/view/4syGWK

[@zsenkrad]

here is the code : float bestDistance = 99999; float2 bestUV = float2(-1,-1); for(int y = -1; y= 0)&&(dist < bestDistance)){ bestDistance = dist; bestUV = tempVaule; } } } return float4(bestUV,0,0);

[@EnriqueVenturaGames]

Ty for posting it! :)

[@gursimranvirdi9097]

for ue5.3.1 can anyone post that part 1 custom code

[@butjok]

I am glad KZbin recommended this channel. Thank you!

[@fuzzyhenry2048]

I did some JFA ping-pong implementation before watching your video and you taught me a lot of pro tips besides the JFA. Thank you.

[@alxleiva]

Hola caballero, your channel is a gold mine! I recently discovered it and I've been binge watching every single video of yours.

[@EnriqueVenturaGames]

Muchas gracias! Thank you for the nice comment! :)

[@0xSirius]

Great tutorial, cant wait to see how you will implement it on the post process material

[@omidmiresmaeili]

Great tutorial. Just wondering if there is a c++ interface for drawing material to render targets to avoid blueprints (for its performance costs)

[@EnriqueVenturaGames]

Thank you! All these functions are available in the UKismetRenderingLibrary: api.unrealengine.com/INT/API/Runtime/Engine/Kismet/UKismetRenderingLibrary/index.html

[@kiyan.videos]

Hey! I loved your Spider-Verse tutorials, and I wonder if you ever plan on making a sort of choppy animation style tutorial. By choppy, I mean how in Spider-Verse, the animations have a lag effect.

[@EnriqueVenturaGames]

Thanks for the comment and the suggestion! I'll look into it and add it to the list of ideas for videos!

[@Oleg.Haritonchik]

Hello, I was inspired by your old demos of JFA post-prosess effects and somehow managed to implement it myself a while ago. It produced quiet nice results beyond outlines, but with very poor performance. Outlines lag on screen when character or object moves too fast. I discovered that performance is heavily dependent on RT size. I used 2 RT and ping-pong method and it gave me tops ~30 FPS with 1024x1024, and ~20 FPS with 2048x2048. I struggled several days to improve performance, tried to use only RG channels, use separate axis of JFA steps iteration and node-based implementation instead of HLSL in materials with no significant success. So I gave up on JFA until your last video. Your trick of using begin/end draw canvas instead of ping-pong saved me significant FPS, yet I'm still at ~48 FPS with 1024x1024, and ~32 FPS with 2048x2048. Can you cover performance topics in your upcoming video? And many thanks for sharing cools stuff.

[@EnriqueVenturaGames]

Maybe not the next one, but I added to the list of ideas for future videos, thanks for the suggestion! :) And yeah, the effect's performance depends a lot on the size of the texture. If you need to use this effect in runtime a lot, I would recommend looking into doing it on a lower resolution, and then upscaling and/or antialiasing the result.

[@Oleg.Haritonchik]

Well I know the exact problem of my method: I use 1 RT to capture scene, Final Color (RGB) as capture source and apply masking post-process (custom stencil) for scene capture component, the result is ~ 25/40 dive in FPS depending on size of RT. My goal was to write only custom depth in R channel and use it to initialize as a mask. Using only 1 channel in first RT greatly reduces the load, the JFA logic itself (only RG) eats ~5-10 FPS max. Unfortunately standard unreal node doesn't have custom depth as capture source and I'm not proficient in c++ to extract it from G-buffer. Maybe if you come up with some solution, please share it on your channel.@@EnriqueVenturaGames

[@Labo3D]

Random question, what's a hypotethical pratical application of this?

[@EnriqueVenturaGames]

I mention it at the beginning of the video: distance fields, wide outlines, voronoi diagrams, shadows... there are quite a few uses for this technique, and it is much more efficient and cheap than other methods

[@adamcboyd]

Any chance you're interested in helping tighten up a developed game that is about to go into playtest after three years of silent development? Would love to see if you can help us optimize it in any way. Its a VR game in Unreal 5.3 and we are doing realistic graphics as opposed to all the cartoony games out there.

[@EnriqueVenturaGames]

Sorry but I'm already a full-time game dev, would love to have the time for that, sounds like an interesting project! Good luck though, and feel free to drop a comment with a link to your game! :)

[@adamcboyd]

@@EnriqueVenturaGames did it eat my reply with the link?

[@EnriqueVenturaGames]

@@adamcboyd Weird, I don't even see it on the "pending review" comment list, maybe it is an automated YT thing

[@adamcboyd]

@@EnriqueVenturaGames I know this is a couple days late but we're you able to see our old GDC trailer?

[@EnriqueVenturaGames]

@@adamcboyd couldn't find it, youtube ate the link; what is the project name, so I can search it?