feat/fix: misc shader changes (fix normals, lighting, uv)

src/app/niko/scene-components/grass.tsx

@@ -7,24 +7,24 @@ import grassVert from './shaders/grass.vert';
 import grassFrag from './shaders/grass.frag';
 
 interface GrassProps {
-    x: number;
-    y: number;
-    size: number;
-    count: number;
-    grassSize: number;
-    scale: number;
-    hillScale: number;
-    hillHeight: number;
-    detailScale: number;
-    detailHeight: number;
-    noise2D: (x: number, y: number) => number;
-    grassLOD: number;
-    dryColor: string;
-    lushColor: string;
-    grassBlades?: number;
-    grassSegments?: number;
-    grassLODStart?: number;
-    grassLODExponent?: number;
+	x: number;
+	y: number;
+	size: number;
+	count: number;
+	grassSize: number;
+	scale: number;
+	hillScale: number;
+	hillHeight: number;
+	detailScale: number;
+	detailHeight: number;
+	noise2D: (x: number, y: number) => number;
+	grassLOD: number;
+	dryColor: string;
+	lushColor: string;
+	grassBlades?: number;
+	grassSegments?: number;
+	grassLODStart?: number;
+	grassLODExponent?: number;
 }
 
 export default function Grass({
@@ -222,62 +222,61 @@ export default function Grass({
 			shader.uniforms.uTime = { value: 0 };
 
 			shader.vertexShader = `
-			uniform float uTime;
-			varying vec2 vGrassUv;
-			
-			float hash(vec2 p) {
-				return fract(sin(dot(p, vec2(127.1, 311.7))) * 43758.5453);
-			}
-			
-			float noise(vec2 p) {
-				vec2 i = floor(p);
-				vec2 f = fract(p);
-				f = f * f * (3.0 - 2.0 * f);
-				
-				float a = hash(i);
-				float b = hash(i + vec2(1.0, 0.0));
-				float c = hash(i + vec2(0.0, 1.0));
-				float d = hash(i + vec2(1.0, 1.0));
-				
-				return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
-			}
-			
-			float fbm(vec2 p) {
-				float value = 0.0;
-				float amplitude = 0.5;
-				float frequency = 1.0;
-				
-				for(int i = 0; i < 4; i++) {
-					value += amplitude * noise(p * frequency);
-					frequency *= 2.0;
-					amplitude *= 0.5;
-				}
-				
-				return value;
-			}
-			
-			${shader.vertexShader}
-		`;
+            uniform float uTime;
+            varying vec2 vGrassUv;
+            varying vec3 vWorldPos;
+            
+            float hash(vec2 p) {
+                return fract(sin(dot(p, vec2(127.1, 311.7))) * 43758.5453);
+            }
+            
+            float noise(vec2 p) {
+                vec2 i = floor(p);
+                vec2 f = fract(p);
+                f = f * f * (3.0 - 2.0 * f);
+                float a = hash(i);
+                float b = hash(i + vec2(1.0, 0.0));
+                float c = hash(i + vec2(0.0, 1.0));
+                float d = hash(i + vec2(1.0, 1.0));
+                return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
+            }
+            
+            float fbm(vec2 p) {
+                float value = 0.0;
+                float amplitude = 0.5;
+                float frequency = 1.0;
+                for(int i = 0; i < 4; i++) {
+                    value += amplitude * noise(p * frequency);
+                    frequency *= 2.0;
+                    amplitude *= 0.5;
+                }
+                return value;
+            }
+            
+            ${shader.vertexShader}
+        `;
+
 			shader.vertexShader = shader.vertexShader.replace(
 				'#include <begin_vertex>',
 				`
-			#include <begin_vertex>
-			vGrassUv = uv;
-			${grassVert}
-			`
+            #include <begin_vertex>
+            ${grassVert}
+            `
 			);
 
 			shader.fragmentShader = `
-			uniform float uTime;
-			varying vec2 vGrassUv;
-			${shader.fragmentShader}
-		`;
+            uniform float uTime;
+            varying vec2 vGrassUv;
+            varying vec3 vWorldPos;
+            ${shader.fragmentShader}
+        `;
+
 			shader.fragmentShader = shader.fragmentShader.replace(
 				'#include <color_fragment>',
 				`
-			#include <color_fragment>
-			${grassFrag}
-			`
+            #include <color_fragment>
+            ${grassFrag}
+            `
 			);
 
 			if (materialRef.current) {

src/app/niko/scene-components/shaders/grass.frag

@@ -1,13 +1,17 @@
-float ao = smoothstep(0.0, 0.7, vGrassUv.y);
-ao = mix(0.05, 1.0, ao);
-
-vec3 rootColor = diffuseColor.rgb * 0.4;
-vec3 tipColor = diffuseColor.rgb * 1.5;
+float ao = smoothstep(0.0, 0.8, vGrassUv.y);
+ao = mix(0.15, 1.0, ao);
 
+vec3 rootColor = diffuseColor.rgb * 0.35;
+vec3 tipColor = diffuseColor.rgb * 1.3;
 vec3 grassColor = mix(rootColor, tipColor, vGrassUv.y);
-grassColor *= ao;
 
-float translucency = pow(vGrassUv.y, 2.0) * 0.5;
-grassColor += diffuseColor.rgb * translucency;
+vec3 viewDir = normalize(cameraPosition - vWorldPos);
+vec3 lightDir = normalize(vec3(15.0, 25.0, 15.0)); 
 
-diffuseColor.rgb = grassColor;
+float backLighting = max(0.0, dot(viewDir, -lightDir));
+backLighting = pow(backLighting, 3.0) * smoothstep(0.2, 1.0, vGrassUv.y);
+
+vec3 sssColor = vec3(0.4, 0.8, 0.3) * diffuseColor.rgb; 
+grassColor += sssColor * backLighting * 1.5;
+
+diffuseColor.rgb = grassColor * ao;

src/app/niko/scene-components/shaders/grass.vert

@@ -1,3 +1,5 @@
+vGrassUv = uv;
+
 vec4 worldPos = modelMatrix * instanceMatrix * vec4(0.0, 0.0, 0.0, 1.0);
 float gx = worldPos.x;
 float gz = worldPos.z;
@@ -8,7 +10,6 @@ float windSpeed = 1.5;
 float windTime = uTime * windSpeed;
 vec2 windSamplePos = (worldPos.xz * 0.05) - (mainWindDir * windTime * 0.2);
 
-
 float windBase = fbm(windSamplePos * 0.8) * 0.4 + 0.2;
 float gustNoise = fbm(windSamplePos * 0.4);
 float gust = pow(gustNoise, 3.0) * 1.8;
@@ -35,4 +36,7 @@ transformed.z += curveAmount * curveDir.y * 0.5;
 float swayAmount = (totalWind + spring) * uv.y * uv.y;
 transformed.x += swayAmount * windDir.x;
 transformed.z += swayAmount * windDir.y;
-transformed.y -= abs(swayAmount) * 0.2;
+transformed.y -= abs(swayAmount) * 0.2;
+
+objectNormal = vec3(0.0, 1.0, 0.0); 
+vWorldPos = (modelMatrix * instanceMatrix * vec4(transformed, 1.0)).xyz;