I have a sea trading game that I'm working on developing. Right now, my world looks like this:

enter image description here

There are 4 different "biomes", with more to be added. Internally, this is a large mesh which has 4 different types of materials added to it, to make it work. Each region has a material associated with it.

The problem that I'm trying to overcome is to make it look less squary, I believe the process is known as bitmasking. The traditional way to do so I believe is to use images to show the boundary between each one, having one for each possible curve. That doesn't work with my current mesh architecture so far as I can tell. What I'm wondering is if there is a way to make the edges of the mesh to be curvy instead of straight lines. I assume it would have to be a shader of some kind, but my mind isn't quite figuring out the specifics of how to make it work. Any tips? Thanks!


2 Answers 2


You could interpolate and make the grid smaller. Basically the idea would be to take those large squares and make them smaller so that the edges are not so obvious.

I posted the algorithm here with an example and some pretty pictures:

Creating colour spectrum by light flux values

Essentially, you would have to take your generated map data array -- and then just stretch it out over a larger map array, making the edges look a lot smoother. This would be an alternative approach to utilizing bitmasking.

Considering you are already converting your map into a mesh, I would assume this wouldn't be much of a performance hit during gameplay, so as long as you pre-calculate it all during the map creation portion.

Edit Alternatively to this -- you could also just sample a larger dataset so that your world is larger to begin with.

  • \$\begingroup\$ That's probably what I'm going to end up doing, although it would have been nice if there was an easier way. Thanks! \$\endgroup\$ Jun 21, 2016 at 13:36

What I ultimately decided to do was to use a single material with all of the texture compiled together, and add a shader. The effect is as follows:

enter image description here

The shader code is below. I added a texture of some pre-generated noise to let it work.

Shader "Custom/Position Blur" {
        _MainTex("Main", 2D) = "white"{}
        _BumpMap("Bumpmap", 2D) = "bump" {}
        _Noise("Position Noise", 2D) = "gray"{}
        _Smoothness("Smoothness", Range(0,1)) = 0.5
        _Metallic("Metallic", Range(0,1)) = 0.5
        _WorldPosOffset("World Offset",Range(1,100)) = 10
        _MovementOffset("Local Offset",Range(1,100)) = 50
        Tags{ "RenderType" = "Opaque" }
        Cull Off
        #include "UnityPBSLighting.cginc"
        #pragma surface surf Standard

        struct Input {
            float2 uv_MainTex;
            float2 uv_BumpMap;
            float3 viewDir;
            float3 worldPos;

        sampler2D _MainTex;
        sampler2D _Noise;
        sampler2D _BumpMap;
        float _Smoothness;
        float _Metallic;
        float _WorldPosOffset;
        float _MovementOffset;

        void surf(Input IN, inout SurfaceOutputStandard o) {
            float2 offset = float2(
                tex2D(_Noise, float2(IN.uv_MainTex.y / _WorldPosOffset, 0)).r-0.5,
                tex2D(_Noise, float2(0, IN.uv_MainTex.x / _WorldPosOffset)).r-0.5
            o.Albedo = tex2D(_MainTex,IN.uv_MainTex+offset/ _MovementOffset);
            o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
            o.Smoothness = _Smoothness;
            o.Metallic = _Metallic;
        Fallback "Diffuse"

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