feat: add NetShader and UnicolorShader with a debug component for visual testing in the world scene

src/shaders/NetShader.ts

@@ -0,0 +1,66 @@
+import { ShaderMaterial, Color, PlaneGeometry, Mesh, Vector2 } from "three";
+
+export const createNetShader = (): ShaderMaterial => {
+  return new ShaderMaterial({
+    uniforms: {
+      uTime: { value: 0 },
+      uGridScale: { value: 15.0 },
+      uPincushionStrength: { value: 0.4 },
+      uBloomIntensity: { value: 0.3 },
+      uGridThickness: { value: 0.02 },
+    },
+    vertexShader: `
+      varying vec2 vUv;
+      
+      void main() {
+        vUv = uv;
+        gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
+      }
+    `,
+    fragmentShader: `
+      uniform float uTime;
+      uniform float uGridScale;
+      uniform float uPincushionStrength;
+      uniform float uBloomIntensity;
+      uniform float uGridThickness;
+      
+      varying vec2 vUv;
+      
+      vec2 applyPincushion(vec2 uv, float strength) {
+        vec2 center = uv - 0.5;
+        float dist = length(center);
+        float distortion = 1.0 + dist * dist * strength;
+        return center * distortion + 0.5;
+      }
+      
+      float grid(vec2 uv, float scale, float thickness) {
+        vec2 gridUV = fract(uv * scale);
+        float lineX = smoothstep(thickness, thickness + 0.01, gridUV.x) 
+                    * smoothstep(1.0 - thickness, 1.0 - thickness - 0.01, gridUV.x);
+        float lineY = smoothstep(thickness, thickness + 0.01, gridUV.y) 
+                    * smoothstep(1.0 - thickness, 1.0 - thickness - 0.01, gridUV.y);
+        return lineX + lineY;
+      }
+      
+      void main() {
+        vec2 uv = applyPincushion(vUv, uPincushionStrength);
+        
+        float gridPattern = grid(uv, uGridScale, uGridThickness);
+        
+        vec3 gridColor = vec3(1.0, 0.4, 0.7);
+        vec3 bgColor = vec3(0.05, 0.02, 0.05);
+        
+        float bloom = gridPattern * uBloomIntensity;
+        vec3 col = mix(bgColor, gridColor + bloom, gridPattern);
+        
+        gl_FragColor = vec4(col, 1.0);
+      }
+    `,
+  });
+};
+
+export const createNetMesh = (): Mesh => {
+  const geometry = new PlaneGeometry(2, 2);
+  const material = createNetShader();
+  return new Mesh(geometry, material);
+};