stylized-scene/src/scene/grass.tsx at main · hmmhmmhm/stylized-scene

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

import { useEffect, useMemo, useRef } from "react";

import { useGLTF } from "@react-three/drei";

import {

InstancedBufferAttribute,

Object3D,

RepeatWrapping,

type InstancedMesh,

type Texture,

} from "three";

import { GRASS, SCENE, TEXTURE_PATHS } from "../config/scene-config";

import { buildGrassMaterial } from "../materials/grass-material";

import { useUniform, useUniformColor } from "../utils/use-uniform";

import { useTextureImageData, sampleImageData } from "../utils/image-data";

import { extractFirstMeshGeometry } from "../utils/mesh-geometry";

import { generateInstanceSeeds } from "../utils/instance-seeds";

import type { DebugMode } from "../types";

type Props = {

density: number;

scale: number;

heightVariation: number;

heightNoiseScale: number;

rootColor: string;

tipColor: string;

rootColorB: string;

tipColorB: string;

colorVariation: number;

colorPatchScale: number;

macroVariation: number;

macroScale: number;

windStrength: number;

windSpeed: number;

windAngle: number;

gustScale: number;

turbulence: number;

flutter: number;

projection: number;

debugMode: DebugMode;

translucency: boolean;

fresnel: boolean;

groundColorMap: Texture;

noiseMap: Texture;

pathMask: Texture;

};

export function Grass({

density,

scale,

heightVariation,

heightNoiseScale,

rootColor,

tipColor,

rootColorB,

tipColorB,

colorVariation,

colorPatchScale,

macroVariation,

macroScale,

windStrength,

windSpeed,

windAngle,

gustScale,

turbulence,

flutter,

projection,

debugMode,

translucency,

fresnel,

groundColorMap,

noiseMap,

pathMask,

}: Props) {

const { scene } = useGLTF(TEXTURE_PATHS.grassBlades);

const { geometry, height: bladeHeight } = useMemo(

() => extractFirstMeshGeometry(scene),

[scene]

);

const pathMaskData = useTextureImageData(pathMask);

const heightVariationU = useUniform(heightVariation);

const heightNoiseScaleU = useUniform(heightNoiseScale);

const rootU = useUniformColor(rootColor);

const tipU = useUniformColor(tipColor);

const rootBU = useUniformColor(rootColorB);

const tipBU = useUniformColor(tipColorB);

const colorVariationU = useUniform(colorVariation);

const colorPatchScaleU = useUniform(colorPatchScale);

const macroVariationU = useUniform(macroVariation);

const macroScaleU = useUniform(macroScale);

const windStrengthU = useUniform(windStrength);

const windSpeedU = useUniform(windSpeed);

const windAngleU = useUniform(windAngle);

const gustScaleU = useUniform(gustScale);

const turbulenceU = useUniform(turbulence);

const flutterU = useUniform(flutter);

const projectionU = useUniform(projection);

const translucencyU = useUniform(translucency ? 1 : 0);

const fresnelU = useUniform(fresnel ? 1 : 0);

useEffect(() => {

noiseMap.wrapS = noiseMap.wrapT = RepeatWrapping;

noiseMap.needsUpdate = true;

}, [noiseMap]);

const material = useMemo(

() =>

buildGrassMaterial({

bladeHeight,

debugMode,

textures: { groundColorMap, noiseMap, pathMask },

uniforms: {

heightVariation: heightVariationU,

heightNoiseScale: heightNoiseScaleU,

rootColor: rootU,

tipColor: tipU,

rootColorB: rootBU,

tipColorB: tipBU,

colorVariation: colorVariationU,

colorPatchScale: colorPatchScaleU,

macroVariation: macroVariationU,

macroScale: macroScaleU,

windStrength: windStrengthU,

windSpeed: windSpeedU,

windAngle: windAngleU,

gustScale: gustScaleU,

turbulence: turbulenceU,

flutter: flutterU,

projection: projectionU,

translucencyEnabled: translucencyU,

fresnelEnabled: fresnelU,

}),

[

bladeHeight,

debugMode,

groundColorMap,

noiseMap,

pathMask,

heightVariationU,

heightNoiseScaleU,

rootU,

tipU,

rootBU,

tipBU,

colorVariationU,

colorPatchScaleU,

macroVariationU,

macroScaleU,

windStrengthU,

windSpeedU,

windAngleU,

gustScaleU,

turbulenceU,

flutterU,

projectionU,

translucencyU,

fresnelU,

]

);

const seeds = useMemo(

() => generateInstanceSeeds(GRASS.MAX_INSTANCES, SCENE.GROUND_SIZE),

[]

);

// Per-instance attributes the wind shader needs, set on the shared geometry

// once so they exist when the material's `attribute(...)` nodes compile:

// - aOrigin: the blade's world XZ. The travelling gust wave is sampled here,

// so each blade reads the wind at its own location (sampling positionWorld

// in the vertex stage collapsed to the same value for every instance, which

// is why the whole field moved in lockstep).

// - aFacing: cos/sin of the blade's yaw, used to counter-rotate the world-space

// bend into the blade's local frame so every blade bends the same world way.

useMemo(() => {

if (!geometry) return;

const origin = new Float32Array(GRASS.MAX_INSTANCES * 2);

const facing = new Float32Array(GRASS.MAX_INSTANCES * 2);

for (let i = 0; i < GRASS.MAX_INSTANCES; i++) {

origin[i * 2 + 0] = seeds[i * 3 + 0];

origin[i * 2 + 1] = seeds[i * 3 + 1];

const yaw = seeds[i * 3 + 2];

facing[i * 2 + 0] = Math.cos(yaw);

facing[i * 2 + 1] = Math.sin(yaw);

}

geometry.setAttribute("aOrigin", new InstancedBufferAttribute(origin, 2));

geometry.setAttribute("aFacing", new InstancedBufferAttribute(facing, 2));

}, [geometry, seeds]);

const ref = useRef<InstancedMesh>(null!);

useEffect(() => {

const mesh = ref.current;

if (!mesh) return;

const dummy = new Object3D();

for (let i = 0; i < density; i++) {

const x = seeds[i * 3 + 0];

const z = seeds[i * 3 + 1];

// The path mask is drawn on the ground via GPU texture sampling, where

// texture.flipY (default true) means uv.v reads source-image row (1 - v).

// getImageData here is top-origin and ignores flipY, so we must sample the

// same source row the GPU lands on: z/size + 0.5 (no V inversion).

const maskValue = pathMaskData

? sampleImageData(

pathMaskData,

x / SCENE.GROUND_SIZE + 0.5,

z / SCENE.GROUND_SIZE + 0.5

)

: 0;

const edgeJitter = (Math.sin(i * 12.9898) * 43758.5453) % 1;

const + (edgeJitter - 0.5) * 0.3 > 0.5;

dummy.position.set(x, 0, z);

dummy.rotation.set(0, seeds[i * 3 + 2], 0);

dummy.scale.setScalar(onPath ? 0 : scale);

dummy.updateMatrix();

mesh.setMatrixAt(i, dummy.matrix);

}

mesh.count = density;

mesh.instanceMatrix.needsUpdate = true;

}, [density, scale, seeds, pathMaskData]);

if (!geometry) return null;

return (

<instancedMesh

ref={ref}

args={[geometry, material, GRASS.MAX_INSTANCES]}

receiveShadow

frustumCulled={false}

);

}

useGLTF.preload(TEXTURE_PATHS.grassBlades);

FilesExpand file tree

grass.tsx

Latest commit

History

grass.tsx

File metadata and controls