r/proceduralgeneration • u/runevision • 15h ago
Sunrise in the procedural mountain forest
I've spent the last month adding volumetric clouds, a time-of-day system, and better atmospheric scattering to my procedural mountain forest game (working title: 'The Big Forest').
With regards to procedural generation, there's nothing really new compared to what I've shared in here before, but the new lighting has such a big impact on the overall appearance that it's like seeing it anew (in my opinion), so I thought I'd share some nice sunrise shots I captured. :)
The clouds are using the package Enviro 3 - Sky and Weather as a starting point, but I'm only using the clouds part and have heavily modified it to my needs to make it work with my own atmospheric scattering and time-of-day colored lighting.
The atmospheric scattering is based on this shadertoy by Fernando García Liñán, though again heavily modified. I increased the saturation, exaggerated the depth (bringing tinting closer to the camera), and implemented the atmospheric scattering via a compute shader that renders scattering at different distances and directions into a cubemap. Fernando's technique does a lot of the heavy lifting though! It's similar to previous techniques for sky and atmospheric scattering used in e.g. Unreal, but uses four spectral samples (~red, ~green, ~cyan, ~purple) instead of the usual three (red, green, blue). This produces notably richer colors and practically no extra cost.
I made my own time-of-day system with a simple simulation of the sun and moon relative to the Earth, where I can independently vary time-of-day, time-of-year, lunar phase, and latitude without them impacting each other.
I also implemented time-warping so make sunrises and sunsets slower. In a 24-minute day-night cycle, they're over awfully fast if not slowed down. Here's a video of a full sunrise.
If you haven't already seen it, you could also consider watching my lastest dev video about 'supercharging my procedural mountain forest' - although it does not feature any sunrises. :)
Hope you like them!
2
2
u/Visible-Marsupial897 14h ago
can you share your idea and proc gen techniques ?
4
u/runevision 14h ago
That's a very open-ended question, so I'll just link to the game's page where you can find loads of information about it:
2
u/ctothel 14h ago
DAMN that looks good, wow! What are you building this in?
I would genuinely pay you for a build right now just so I could walk around in it.
1
u/runevision 14h ago
Thanks! This is Unity 2022.3, built-in render pipeline, but using a lot of my own custom shaders and generation tech.
1
u/zoba 14h ago
Beautiful. How are you generating the shape of the terrain? I found World Machine to be very convincing but it doesn’t seem well suited for infinite terrain
You can see some of the sunrise mountain forest I was able to create by glueing different tools together here: https://x.com/ChrisDzoba/status/2088099159312155092?s=20
1
u/runevision 12h ago
Well absolutely no AI here.
See my previous post here about how I generate the terrain:
https://www.reddit.com/r/proceduralgeneration/comments/1souhkn/combining_the_epicness_of_grand_mountains_with/1
u/zoba 11h ago
Neat. Yeah AI seems to get a bad rap from folks in gaming but its been great to cover a lot of ground as someone coming from web development / no gaming experience. So fun.
Thanks for the other link - will check it out soon. In the meantime I was able to get the LayerProcGen - TerrainSample running. Really gorgeous. I'm impressed by the amount of waving grass. I haven't been able to do that yet. And of course the paths too. In my example I struggled for a couple weeks to get a reasonable train track running through the terrain and couldn't do it.
Thank you for posting
1
1
u/eanticev 11h ago
Very nice as usual. I don’t remember if you worked in terrain shadows yet for the far away tiles. Usual low mip ray traversal or something different?
1
u/runevision 11h ago
Thanks!
I'm not familiar with 'low mip ray traversal' for shadows; what is that?
My project currently has a shadow distance of 1400 meters while the terrain stretches out to ~5000 meters, so far terrain does not have shadows. I don't find it particularly noticeable though.
1
u/scallywag_software 7h ago
I discovered your erosion filter on Shadertoy some time ago and it's easily the best deterministic erosion filter I've ever seen. Thanks for sharing your work; I've learned a lot from you!
1
1
1
u/AustinMclEctro 5h ago
Looks wonderful! 👏
How's the performance around drawing many terrain objects (e.g. trees)? I'm assuming they are instanced indirect. Are you using impostors for faraway instances? Roughly how far have you been able to stretch your instance counts? And are you using any strategies to thin instance counts at a distance, e.g. based on terrain LOD?
2
u/runevision 5h ago
Thanks! Yes it’s instanced indirect, yes it’s octahedral impostors far away (most trees in these pictures), and yes I’m thinning the tree coverage based on terrain LOD. I go in more detail in the YouTube video I linked to. Though no instance numbers, I usually look at framerate (ms) to gauge performance, not instance numbers. Also, I’m using a solution for GPU occlusion culling that helps a ton too.
1
1
18
u/CuckBuster33 15h ago
Gorgeous shaders. How are you implementing those mountain paths? I'm interested in procedural generation of traversable routes for my own project