File size: 10,972 Bytes
b797337 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 | /** @import { StructTypeNode } from 'three/webgpu' */
/** @import { BVHComputeData } from '../BVHComputeData.js' */
import { Vector4 } from 'three';
import { BYTES_PER_NODE, UINT32_PER_NODE, IS_LEAFNODE_FLAG } from '../../core/Constants.js';
import { IS_LEAF, LEFT_NODE, RIGHT_NODE } from '../../core/utils/nodeBufferUtils.js';
// scratch
const _def = /* @__PURE__ */ new Vector4();
const _vec = /* @__PURE__ */ new Vector4();
// resolve an indirect buffer into a flat triangle index array
function dereferenceIndex( indexAttr, indirectBuffer ) {
const indexArray = indexAttr ? indexAttr.array : null;
const result = new Uint32Array( indirectBuffer.length * 3 );
for ( let i = 0, l = indirectBuffer.length; i < l; i ++ ) {
const i3 = 3 * i;
const v3 = 3 * indirectBuffer[ i ];
for ( let c = 0; c < 3; c ++ ) {
result[ i3 + c ] = indexArray ? indexArray[ v3 + c ] : v3 + c;
}
}
return result;
}
/**
* Copies the packed nodes of the TLAS into the shared node buffer, encoding each leaf as a TLAS leaf
* (`0xFF00` tag) from its `primitiveInfo` entry.
*
* @private
* @param {Object} bvh
* @param {Array|null} primitiveInfo - Per-primitive `{ transformSlot, nodeOffset }` used to encode TLAS
* leaves. Pass null to write only the node bounds and leave the existing node data in place, as when
* refreshing a refit tree whose topology is unchanged.
* @param {number} nodeWriteOffset
* @param {ArrayBuffer} target
*/
export function appendBVHData( bvh, primitiveInfo, nodeWriteOffset, target ) {
const targetU32 = new Uint32Array( target );
const targetF32 = new Float32Array( target );
bvh._roots.forEach( root => {
const rootBuffer16 = new Uint16Array( root );
const rootBuffer32 = new Uint32Array( root );
for ( let i = 0, l = root.byteLength / BYTES_PER_NODE; i < l; i ++ ) {
const r32 = i * UINT32_PER_NODE;
const r16 = r32 * 2;
const n32 = nodeWriteOffset * UINT32_PER_NODE;
// write bounds
const view = new Float32Array( root, i * BYTES_PER_NODE, 6 );
if ( i === 0 ) {
// if we're copying the root then check for cases where there are no primitives and therefore
// be a bounds of [ Infinity, - Infinity ]. Convert this to [ 1, - 1 ] for reliable GPU behavior.
for ( let i = 0; i < 3; i ++ ) {
const vMin = view[ i + 0 ];
const vMax = view[ i + 3 ];
if ( vMin > vMax ) {
targetF32[ n32 + i + 0 ] = 1;
targetF32[ n32 + i + 3 ] = - 1;
} else {
targetF32[ n32 + i + 0 ] = vMin;
targetF32[ n32 + i + 3 ] = vMax;
}
}
} else {
targetF32.set( view, n32 );
}
// a refit only moves bounds, so the node data written on the first pass remains valid
if ( primitiveInfo === null ) {
nodeWriteOffset ++;
continue;
}
const isLeaf = IS_LEAF( r16, rootBuffer16 );
if ( isLeaf ) {
// TLAS leaf - stores the placement / transform slot (low 24 bits, tagged with
// 0xFF in the top byte) and the cluster subtree's absolute node offset, which the
// GPU enters directly as the BLAS entry node.
const offset = rootBuffer32[ r32 + 6 ];
const count = rootBuffer16[ r16 + 14 ];
// an empty bvh produces a single primitiveless leaf with no primitiveInfo entry; its
// degenerate bounds keep the GPU from traversing into it, so write an empty placeholder.
const { transformSlot, nodeOffset } = count === 0 ? { transformSlot: 0, nodeOffset: 0 } : primitiveInfo[ offset ];
if ( transformSlot > 0x00ffffff ) {
throw new Error( `packBVHBufferUtils: transform slot ${ transformSlot } exceeds the 24-bit TLAS leaf limit.` );
}
targetU32[ n32 + 6 ] = nodeOffset;
targetU32[ n32 + 7 ] = 0xFF000000 | ( transformSlot & 0x00ffffff );
} else {
targetU32[ n32 + 6 ] = rootBuffer32[ r32 + 6 ];
targetU32[ n32 + 7 ] = rootBuffer32[ r32 + 7 ];
}
nodeWriteOffset ++;
}
} );
}
/**
* Counts the nodes in the contiguous (depth-first) subtree rooted at "nodeIndex". A subtree's node
* count is `rightOffset + subtreeSize(rightChild)`, unwinding down the right spine.
*
* @private
* @param {ArrayBuffer} root - A single BVH root's packed node buffer.
* @param {number} nodeIndex - Node index (in node units) of the subtree root.
* @returns {number}
*/
export function getSubtreeNodeCount( root, nodeIndex ) {
return spanOf( new Uint16Array( root ), new Uint32Array( root ), nodeIndex );
}
// exact contiguous span ( node count ) of the subtree rooted at "nodeIndex"
function spanOf( rootBuffer16, rootBuffer32, nodeIndex ) {
const isLeaf = IS_LEAF( nodeIndex * UINT32_PER_NODE * 2, rootBuffer16 );
if ( isLeaf ) {
return 1;
}
const rightOffset = rootBuffer32[ nodeIndex * UINT32_PER_NODE + 6 ];
return rightOffset + spanOf( rootBuffer16, rootBuffer32, nodeIndex + rightOffset );
}
/**
* Returns the number of nodes along the deepest root-to-leaf path of the subtree rooted at
* node index "start". A lone leaf has a depth of 1.
*
* @private
* @param {ArrayBuffer} root - A single BVH root's packed node buffer.
* @param {number} start - Node index of the subtree root.
* @returns {number}
*/
export function getMaxNodeDepth( root, start = 0 ) {
const rootBuffer16 = new Uint16Array( root );
const rootBuffer32 = new Uint32Array( root );
let maxDepth = 0;
traverse( start * UINT32_PER_NODE, 1 );
return maxDepth;
function traverse( node, depth ) {
const n32 = node;
const n16 = node * 2;
const isLeaf = IS_LEAF( n16, rootBuffer16 );
if ( isLeaf ) {
maxDepth = Math.max( depth, maxDepth );
} else {
const right = RIGHT_NODE( n32, rootBuffer32 );
const left = LEFT_NODE( n32 );
traverse( left, depth + 1 );
traverse( right, depth + 1 );
}
}
}
/**
* Copies a single contiguous subtree (`[ subtreeStart, subtreeStart + subtreeSize )`) of a BVH root
* into the shared node buffer, rebasing leaf triangle offsets by "geometryOffset". Internal nodes'
* child offsets are relative and so remain valid on the contiguous copy.
*
* @private
* @param {ArrayBuffer} root - The BVH root's packed node buffer.
* @param {number} subtreeStart - Node index of the subtree root.
* @param {number} subtreeSize - Number of nodes in the subtree.
* @param {number} geometryOffset - Triangle base added to leaf offsets.
* @param {number} nodeWriteOffset - Node index in "target" to write the subtree root to.
* @param {ArrayBuffer} target
*/
export function appendBVHSubtree( root, subtreeStart, subtreeSize, geometryOffset, nodeWriteOffset, target ) {
const targetU16 = new Uint16Array( target );
const targetU32 = new Uint32Array( target );
const targetF32 = new Float32Array( target );
const rootBuffer16 = new Uint16Array( root );
const rootBuffer32 = new Uint32Array( root );
for ( let k = 0; k < subtreeSize; k ++ ) {
const src = subtreeStart + k;
const r32 = src * UINT32_PER_NODE;
const r16 = r32 * 2;
const n32 = nodeWriteOffset * UINT32_PER_NODE;
const n16 = n32 * 2;
// write bounds - fix up an empty subtree root's [ Infinity, -Infinity ] to [ 1, -1 ]
const view = new Float32Array( root, src * BYTES_PER_NODE, 6 );
if ( k === 0 ) {
for ( let c = 0; c < 3; c ++ ) {
const vMin = view[ c + 0 ];
const vMax = view[ c + 3 ];
if ( vMin > vMax ) {
targetF32[ n32 + c + 0 ] = 1;
targetF32[ n32 + c + 3 ] = - 1;
} else {
targetF32[ n32 + c + 0 ] = vMin;
targetF32[ n32 + c + 3 ] = vMax;
}
}
} else {
targetF32.set( view, n32 );
}
const isLeaf = IS_LEAF( r16, rootBuffer16 );
if ( isLeaf ) {
// mesh leaf ( 0xFFFF ) - rebase the triangle offset into the packed index buffer
targetU32[ n32 + 6 ] = rootBuffer32[ r32 + 6 ] + geometryOffset;
targetU16[ n16 + 14 ] = rootBuffer16[ r16 + 14 ];
targetU16[ n16 + 15 ] = IS_LEAFNODE_FLAG;
} else {
// internal node - the right-child offset is relative, so it is valid as-is on the copy
targetU32[ n32 + 6 ] = rootBuffer32[ r32 + 6 ];
targetU32[ n32 + 7 ] = rootBuffer32[ r32 + 7 ];
}
nodeWriteOffset ++;
}
}
/**
* Writes the triangle index data for a BVH's geometry into the shared index buffer, rebasing the
* indices into the packed attribute buffer.
*
* @private
* @param {Object} bvh
* @param {{start:number,count:number,vertexStart:number}} range
* @param {number} valueOffset
* @param {number} writeOffset
* @param {Uint32Array} target
*/
export function appendIndexData( bvh, range, valueOffset, writeOffset, target ) {
const { geometry } = bvh;
const { start, count, vertexStart } = range;
if ( bvh.indirect ) {
const dereferencedIndex = dereferenceIndex( geometry.index, bvh._indirectBuffer );
for ( let i = 0; i < dereferencedIndex.length; i ++ ) {
target[ i + writeOffset ] = dereferencedIndex[ i ] - vertexStart + valueOffset;
}
} else if ( geometry.index ) {
for ( let i = 0; i < count; i ++ ) {
target[ i + writeOffset ] = geometry.index.getX( i + start ) - vertexStart + valueOffset;
}
} else {
for ( let i = 0; i < count; i ++ ) {
target[ i + writeOffset ] = i + start + valueOffset;
}
}
}
/**
* Writes a BVH's interleaved per-vertex attributes into the shared attribute buffer, filling missing
* attributes with their defaults and applying bone transforms for skinned meshes.
*
* @private
* @param {Object} bvh
* @param {{vertexStart:number,vertexCount:number}} range
* @param {number} writeOffset
* @param {ArrayBuffer} target
* @param {StructTypeNode} attributeStruct
* @param {BVHComputeData} bvhData - Provides per-attribute defaults via `getDefaultAttributeValue`.
*/
export function appendGeometryData( bvh, range, writeOffset, target, attributeStruct, bvhData ) {
// if "mesh" is present then it is assumed to be a SkinnedMeshBVH
const { geometry, mesh = null } = bvh;
const { vertexStart, vertexCount } = range;
const attributesBufferF32 = new Float32Array( target );
const attrStructLength = attributeStruct.getLength();
attributeStruct.membersLayout.forEach( ( { name }, interleavedOffset ) => {
// TODO: we should be able to have access to memory layout offsets here via the struct
// API but it's not currently available.
const attr = geometry.attributes[ name ];
bvhData.getDefaultAttributeValue( name, _def );
for ( let i = 0; i < vertexCount; i ++ ) {
if ( attr ) {
_vec.fromBufferAttribute( attr, i + vertexStart );
switch ( attr.itemSize ) {
case 1:
_vec.y = _def.y;
_vec.z = _def.z;
_vec.w = _def.w;
break;
case 2:
_vec.z = _def.z;
_vec.w = _def.w;
break;
case 3:
_vec.w = _def.w;
break;
}
if ( mesh && ( name === 'position' || name === 'normal' || name === 'tangent' ) ) {
mesh.applyBoneTransform( i + vertexStart, _vec );
}
} else {
_vec.copy( _def );
}
_vec.toArray( attributesBufferF32, ( writeOffset + i ) * attrStructLength + interleavedOffset * 4 );
}
} );
}
|