I have a shader which basically just uses perlin noise to layer several textures on top of eachother.
The texture is pixel art and i want it to be pixel perfect.
![alt text][1]
[1]: https://cdn.discordapp.com/attachments/404681432238391307/792626704068640788/xq2fb87g4m761.png
On the left is a screencap taken from the editor view while the scene is paused. You can see that the texture is exactly pixel perfect.
On the right is a screencap taken from a render target which the game camera renders to.
You can see that the pixel perfectness is gone, in several places the grass is 2px thick.
Every other sprite the camera renders to the render target doesn't have this problem. It's just this shader that has issues. My assumption is that the pixel art texture isn't aligned to the "grid" that everything else is on, so when the camera tries to render what it sees, there are pixels of grass that overlap more than 1 pixel technically. And since it uses point filtering, it renders 2 pixels of grass.
I think this issue needs to be solved at the shader level and the UV it uses needs to be worldspace or something but i dunno how i can rewrite it to work properly.
Here's the current shader:
Shader "Custom/TexBlend3"
{
Properties
{
_GridSize ("GridSize", float) = 1.0
_X ("Seed X", float) = 1.0
_Y ("Seed Y", float) = 1.0
_ScaleX ("Scale X", float) = 1.0
_ScaleY ("Scale Y", float) = 1.0
_Threshold1 ("Tex 1-2 Threshold", float) = 0.3
_Threshold2 ("Tex 2-3 Threshold", float) = 0.6
_Tex1 ("Tex1", 2D) = "white" {}
_Tex2 ("Tex2", 2D) = "white" {}
_Tex3 ("Tex3", 2D) = "white" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
Pass
{
CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
#include "UnityCG.cginc"
float4 permute(float4 x)
{
return fmod(34.0 * pow(x, 2) + x, 289.0);
}
float2 fade(float2 t) {
return 6.0 * pow(t, 5.0) - 15.0 * pow(t, 4.0) + 10.0 * pow(t, 3.0);
}
float4 taylorInvSqrt(float4 r) {
return 1.79284291400159 - 0.85373472095314 * r;
}
#define DIV_289 0.00346020761245674740484429065744f
float mod289(float x)
{
return x - floor(x * DIV_289) * 289.0;
}
float PerlinNoise2D(float2 P)
{
float4 Pi = floor(P.xyxy) + float4(0.0, 0.0, 1.0, 1.0);
float4 Pf = frac (P.xyxy) - float4(0.0, 0.0, 1.0, 1.0);
float4 ix = Pi.xzxz;
float4 iy = Pi.yyww;
float4 fx = Pf.xzxz;
float4 fy = Pf.yyww;
float4 i = permute(permute(ix) + iy);
float4 gx = frac(i / 41.0) * 2.0 - 1.0 ;
float4 gy = abs(gx) - 0.5 ;
float4 tx = floor(gx + 0.5);
gx = gx - tx;
float2 g00 = float2(gx.x,gy.x);
float2 g10 = float2(gx.y,gy.y);
float2 g01 = float2(gx.z,gy.z);
float2 g11 = float2(gx.w,gy.w);
float4 norm = taylorInvSqrt(float4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11)));
g00 *= norm.x;
g01 *= norm.y;
g10 *= norm.z;
g11 *= norm.w;
float n00 = dot(g00, float2(fx.x, fy.x));
float n10 = dot(g10, float2(fx.y, fy.y));
float n01 = dot(g01, float2(fx.z, fy.z));
float n11 = dot(g11, float2(fx.w, fy.w));
float2 fade_xy = fade(Pf.xy);
float2 n_x = lerp(float2(n00, n01), float2(n10, n11), fade_xy.x);
float n_xy = lerp(n_x.x, n_x.y, fade_xy.y);
return 2.3 * n_xy;
}
float _GridSize;
float _X;
float _Y;
float _ScaleX;
float _ScaleY;
float _Threshold1;
float _Threshold2;
sampler2D _Tex1;
sampler2D _Tex2;
sampler2D _Tex3;
fixed4 frag(v2f_img i): SV_Target
{
float2 uv = i.uv;
uv *= _GridSize;
uv += float2(_X, _Y);
uv /= float2(_ScaleX, _ScaleY);
float ns = PerlinNoise2D(uv) / 2 + 0.5f;
if (ns < _Threshold1)
{
return tex2D(_Tex1, i.uv);
}
if (ns < _Threshold2)
{
return tex2D(_Tex2, i.uv);
}
return tex2D(_Tex3, i.uv);
}
ENDCG
}
}
}
If anyone can point out how i could render the texture using a worldspace UV i'd appreciate it.
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