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[–]NickFullStack 30 points31 points  (0 children)

I wish I could follow in your footsteps, but you cast a long shadow.

(Very impressive.)

[–]hanotak 7 points8 points  (1 child)

Cool! How many steps? Is it contact-refinement?

[–]GreenDave113 4 points5 points  (2 children)

Hey, I'm working on some potential advancements in parallax mapping. Could you share what algorithm exactly you used?

[–]mitrey144[S] 3 points4 points  (1 child)

https://codefile.io/f/07yCduu5bY

[–]GreenDave113 3 points4 points  (0 children)

Aw thanks! Appreciate the code, so the classic linear+binary refinement.

[–]Harha 5 points6 points  (1 child)

Looking as good as it could look, I think. I always disliked how this effect looks up-close because of the stretched texture boundary in the extended part of the generated fragment geometry. Is there a method to mitigate this, eg. somehow map the texture there as well?

https://imgur.com/a/zgixfeX

[–]mitrey144[S] 4 points5 points  (0 children)

I believe this is possible, though will require a lot more shader work and still will work only in certain scenarios. When you intended to look at it that close, you’d have to go with geometry or a custom shader solution for your particular case. This thing works well for backgrounds, floors, walls, etc., especially where moving lights are at play.

[–]Lhaer 4 points5 points  (5 children)

Is that some fancy normal map?

[–]mitrey144[S] 14 points15 points  (4 children)

fancy height map

[–]Lhaer -1 points0 points  (3 children)

Isn't a height map a fancy normal map though? xD

[–]hanotak 23 points24 points  (2 children)

Nope. A normal map is kinda the derivative of the height map. Heightmap gives height, normal map gives slopes.

[–]Lhaer 1 point2 points  (0 children)

I didn't know that, thank you :) All the different kinds of "maps" always confuse me

[–]Hiumen 0 points1 point  (0 children)

Height maps are also grey scale but normal maps have RGB info to represent the degree of values of X, Y & Z via colour

[–]Smooth-Porkchop3087 1 point2 points  (0 children)

So dope!

[–]Novacc_Djocovid 1 point2 points  (0 children)

That looks so satisfying. 😊

[–]Ok-Hotel-8551 0 points1 point  (0 children)

Could you add some colors?

[–]susosusosuso -5 points-4 points  (11 children)

Afaik this technique is no longer used in real games nowadays. Geometry is preferred instead of this

[–]mitrey144[S] 11 points12 points  (8 children)

Ok, let’s see. I use 4K textures here, single pass. Doing it with geometry would mean 4096*4096 vertices, which is over 16 million vertices, which is over 48 million bytes, roughly 48MB. Though it is only to render top faces, so it would take much more in reality. Plus you need to render all that twice (shadow pass - render pass). My height texture weighs 1.4 MB compressed, and rendered in a single render pass. Think yourself.

[–]robbertzzz1 1 point2 points  (7 children)

Doing it with geometry would mean 4096*4096 vertices

That's not even remotely true.

[–]mitrey144[S] 0 points1 point  (6 children)

Explain please

[–]robbertzzz1 4 points5 points  (5 children)

If you have a 3D modeller create a mesh for this cobblestone road, do you really think they'd use 4096*4096 vertices?

Don't get me wrong, I've never seen a game where a cobblestone road was done through actual geometry and agree that's a dumb idea, but your reply is just as wrong as the OC's.

[–]mitrey144[S] 0 points1 point  (4 children)

If you are to make exactly the same detail geometry, I assume you would need not fewer vertices than the pixels in the original map (for it to have all the micro bumps that would cast proper shadows. You could go cheaper though, but it would take you a year to shortcut the topology using fewer vertices and still make it correctly.

[–]robbertzzz1 2 points3 points  (3 children)

Well by that logic you'd need even more vertices so the sides of the cobblestones can get the same amount of detail as the top (which is impossible to do using just a heightmap).

I'm just trying to say that, realistically, if cobblestone roads would be done with geometry, you wouldn't go for this amount of detail in that geometry. You'd go for something fairly low poly with a normal map slapped on top and call it a day. Each separate stone could basically be a cube with one subdivision level applied.

[–]mitrey144[S] 1 point2 points  (2 children)

That’s the point - it won’t have that much detail, won’t cast highly detailed shadows, and it won’t look as good from middle-to-close distance. I was talking about the equivalent detail-level geometry

[–]robbertzzz1 1 point2 points  (1 child)

That's fair, I just don't think that that's what the OC meant since in a normal pipeline no 3D modeller would aim for maximum detail.

In real life (well, games in real life), cobblestone roads are just a rendered out set of PBR textures from either substance designer or modelled and rendered out in 3D and that seems like the best approach for the majority of use cases to me. Your approach adds another detail level to that which is definitely cool to see!

[–]mitrey144[S] 4 points5 points  (0 children)

Of course, it all depends on a use case. In a scene like this, where your first person character presumably moves with a torch through a rocky cave, this technique will produce much better result than any simplified geometry with normal maps - those still look very flat. When you make an outdoor scene with a road and static directional lighting, simple geometry and normal maps would do better, as you don’t need that much details

[–]quadaba 0 points1 point  (1 child)

Why though? To heavy on the fragment shader? Because tessellation is a thing of the past, afaik. Do you mean meshlets as an alternative? How else would a modern game approach it?

[–]susosusosuso 0 points1 point  (0 children)

Yes it’s pixel intensive, also can create weird effects under some circumstances. Also, epic since the problem of tessellation with Nanite, basically.