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Just Grass (Day)

A simple building map with realism, features, and neutrality in mind.

I knew of no flat grass sandbox map that had the features, quality, and addon support that I wanted, so I made it myself.
This map is pretty simple: nothing but grass and a blue sky, with all sides nearly reaching the Hammer grid limit. You have tons of horizontal space, and more than plenty of vertical space. It supports CSM and has actual good quality cubemaps.

This map aims to have realistic lighting, feature support, and high resolution cubemaps while also serving as a better template for save making compared to gm_flatgrass. Ambient lighting is based on the color of the sky, like in real life. RTT shadows are neutral gray for the best looking CSM blobby shadows. Lighting without CSM is also directly downwards for a neutral look. The sun's position is also nearly physically accurate, thanks to a solar calculator that I used.

Play with r_radiosity 4 for best results, since 3 works poorly on this map and is usually less accurate anyway.
I would also recommend spawning a prop at spawn, so you know how far away you are.
If you want snow, try this addon for now. Cubemaps obviously won't have snow in them, like in GTA Online. Disable bloom to not get flashbanged.

File name: gm_justgrass

• Grass
  
• Open source! See "How to get the VMF" below.
  
• 3D skybox
  
• HDR and LDR
  
• 512x512 cubemaps for both HDR and LDR with no mipmap limit, built with 8x SGSSAA
  
• Navmesh that includes skybox areas and is optimized
  
• Basic AI nodes for ground NPCs only
  
• Full CSM and StormFox support (won't report 100% compatibility, but logic_relay isn't needed for this map)
  
• Accurately sized and placed sun based on a given location and time (11:00 AM in the Atlantic Ocean)
  
• HD compressed map icon (JPEG with a PNG file extension)
  
• Realistic and directly downward lighting (ambient lighting is also based on sky color; the angle changes to the sun's upon enabling CSM; this is intended)
  
• Realistic, customizable sky
  
• Lightmaps have decent detail for dynamic lights without having terrible rendering performance (though they still break down at small sizes like 16)
  
• Hopefully good and variated wind
  
• RTT shadows have a high casting distance and are a neutral color for CSM blobby shadows (RGB 128, 128, 128)
  
• Custom tonemapping (min exposure 0.7, max 4, bloom scale 0.2)
  
• A sun that matches the light_environment color, and doesn't get a big glow when you look at it
  
• No sky seams at the end of the map where the 3D skybox starts
  
• Fog blending! Fog color changes dynamically to better match the sky. Doesn't adapt to other skies.
  
• The ground properly aligns with Minecraft SWEP blocks (but not the SProps or hunter grids).

• Grass retextures and modified skies don't show on cubemaps (cause they're baked). You can extract the addon and place the bsp in your maps folder, set your resolution to 3840x2160, and build cubemaps with your texture/sky modifications present.
  
• Due to the ground being so close to the map limits, props with origin points way outside their collisions will get deleted from Garry's Mod's crazy physics detection if they go too close to the ground. An example of a prop that gets removed is "models/props_combine/combine_bridge_b.mdl". Risky workaround: sv_crazyphysics_remove 0;sv_crazyphysics_defuse 0.
  
• Sun lighting color slightly changes upon enabling CSM.
  
• Skybox ground doesn't align perfectly with the playable area ground (seemingly unfixable).
  
• CSM shadows disappear when going too high up (don't know how to fix).

Things that will be coming in the next map version:

• Nothing here...

Planned:

• Nothing here...

Things that might happen:

• Night, dawn, morning, overcast, and snow versions (as separate releases).
  
• Infmap version? If I can find out how to make an infinite map, I might attempt to do this.
  
• Lighting colors calculated from sun pitch (might not happen).
  
• Change the time to true noon.

Extract gm_justgrass.vmf.vmt located in materials/mapsrc from the addon and remove the vmt extension, so it becomes a vmf file (gm_justgrass.vmf).