diff --git a/thirdparty/meshoptimizer/meshoptimizer.h b/thirdparty/meshoptimizer/meshoptimizer.h index be4b765d97..463fad29da 100644 --- a/thirdparty/meshoptimizer/meshoptimizer.h +++ b/thirdparty/meshoptimizer/meshoptimizer.h @@ -328,6 +328,11 @@ MESHOPTIMIZER_EXPERIMENTAL void meshopt_encodeFilterExp(void* destination, size_ */ MESHOPTIMIZER_EXPERIMENTAL size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error); +/** + * Experimental: Mesh simplifier with attribute metric; attributes follow xyz position data atm (vertex data must contain 3 + attribute_count floats per vertex) + */ +MESHOPTIMIZER_EXPERIMENTAL size_t meshopt_simplifyWithAttributes(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_data, size_t vertex_count, size_t vertex_stride, size_t target_index_count, float target_error, float* result_error, const float* attributes, const float* attribute_weights, size_t attribute_count); + /** * Experimental: Mesh simplifier (sloppy) * Reduces the number of triangles in the mesh, sacrificing mesh appearance for simplification performance diff --git a/thirdparty/meshoptimizer/simplifier.cpp b/thirdparty/meshoptimizer/simplifier.cpp index a74b08a97d..5e92e2dc73 100644 --- a/thirdparty/meshoptimizer/simplifier.cpp +++ b/thirdparty/meshoptimizer/simplifier.cpp @@ -20,6 +20,8 @@ #define TRACESTATS(i) (void)0 #endif +#define ATTRIBUTES 8 + // This work is based on: // Michael Garland and Paul S. Heckbert. Surface simplification using quadric error metrics. 1997 // Michael Garland. Quadric-based polygonal surface simplification. 1999 @@ -371,6 +373,10 @@ static void classifyVertices(unsigned char* result, unsigned int* loop, unsigned struct Vector3 { float x, y, z; + +#if ATTRIBUTES + float a[ATTRIBUTES]; +#endif }; static float rescalePositions(Vector3* result, const float* vertex_positions_data, size_t vertex_count, size_t vertex_positions_stride) @@ -427,6 +433,13 @@ struct Quadric float a10, a20, a21; float b0, b1, b2, c; float w; + +#if ATTRIBUTES + float gx[ATTRIBUTES]; + float gy[ATTRIBUTES]; + float gz[ATTRIBUTES]; + float gw[ATTRIBUTES]; +#endif }; struct Collapse @@ -469,6 +482,16 @@ static void quadricAdd(Quadric& Q, const Quadric& R) Q.b2 += R.b2; Q.c += R.c; Q.w += R.w; + +#if ATTRIBUTES + for (int k = 0; k < ATTRIBUTES; ++k) + { + Q.gx[k] += R.gx[k]; + Q.gy[k] += R.gy[k]; + Q.gz[k] += R.gz[k]; + Q.gw[k] += R.gw[k]; + } +#endif } static float quadricError(const Quadric& Q, const Vector3& v) @@ -494,6 +517,17 @@ static float quadricError(const Quadric& Q, const Vector3& v) r += ry * v.y; r += rz * v.z; +#if ATTRIBUTES + // see quadricUpdateAttributes for general derivation; here we need to add the parts of (eval(pos) - attr)^2 that depend on attr + for (int k = 0; k < ATTRIBUTES; ++k) + { + float a = v.a[k]; + + r += a * a * Q.w; + r -= 2 * a * (v.x * Q.gx[k] + v.y * Q.gy[k] + v.z * Q.gz[k] + Q.gw[k]); + } +#endif + float s = Q.w == 0.f ? 0.f : 1.f / Q.w; return fabsf(r) * s; @@ -517,6 +551,13 @@ static void quadricFromPlane(Quadric& Q, float a, float b, float c, float d, flo Q.b2 = c * dw; Q.c = d * dw; Q.w = w; + +#if ATTRIBUTES + memset(Q.gx, 0, sizeof(Q.gx)); + memset(Q.gy, 0, sizeof(Q.gy)); + memset(Q.gz, 0, sizeof(Q.gz)); + memset(Q.gw, 0, sizeof(Q.gw)); +#endif } static void quadricFromPoint(Quadric& Q, float x, float y, float z, float w) @@ -569,6 +610,84 @@ static void quadricFromTriangleEdge(Quadric& Q, const Vector3& p0, const Vector3 quadricFromPlane(Q, normal.x, normal.y, normal.z, -distance, length * weight); } +#if ATTRIBUTES +static void quadricUpdateAttributes(Quadric& Q, const Vector3& p0, const Vector3& p1, const Vector3& p2, float w) +{ + // for each attribute we want to encode the following function into the quadric: + // (eval(pos) - attr)^2 + // where eval(pos) interpolates attribute across the triangle like so: + // eval(pos) = pos.x * gx + pos.y * gy + pos.z * gz + gw + // where gx/gy/gz/gw are gradients + Vector3 p10 = {p1.x - p0.x, p1.y - p0.y, p1.z - p0.z}; + Vector3 p20 = {p2.x - p0.x, p2.y - p0.y, p2.z - p0.z}; + + // we compute gradients using barycentric coordinates; barycentric coordinates can be computed as follows: + // v = (d11 * d20 - d01 * d21) / denom + // w = (d00 * d21 - d01 * d20) / denom + // u = 1 - v - w + // here v0, v1 are triangle edge vectors, v2 is a vector from point to triangle corner, and dij = dot(vi, vj) + const Vector3& v0 = p10; + const Vector3& v1 = p20; + float d00 = v0.x * v0.x + v0.y * v0.y + v0.z * v0.z; + float d01 = v0.x * v1.x + v0.y * v1.y + v0.z * v1.z; + float d11 = v1.x * v1.x + v1.y * v1.y + v1.z * v1.z; + float denom = d00 * d11 - d01 * d01; + float denomr = denom == 0 ? 0.f : 1.f / denom; + + // precompute gradient factors + // these are derived by directly computing derivative of eval(pos) = a0 * u + a1 * v + a2 * w and factoring out common factors that are shared between attributes + float gx1 = (d11 * v0.x - d01 * v1.x) * denomr; + float gx2 = (d00 * v1.x - d01 * v0.x) * denomr; + float gy1 = (d11 * v0.y - d01 * v1.y) * denomr; + float gy2 = (d00 * v1.y - d01 * v0.y) * denomr; + float gz1 = (d11 * v0.z - d01 * v1.z) * denomr; + float gz2 = (d00 * v1.z - d01 * v0.z) * denomr; + + for (int k = 0; k < ATTRIBUTES; ++k) + { + float a0 = p0.a[k], a1 = p1.a[k], a2 = p2.a[k]; + + // compute gradient of eval(pos) for x/y/z/w + // the formulas below are obtained by directly computing derivative of eval(pos) = a0 * u + a1 * v + a2 * w + float gx = gx1 * (a1 - a0) + gx2 * (a2 - a0); + float gy = gy1 * (a1 - a0) + gy2 * (a2 - a0); + float gz = gz1 * (a1 - a0) + gz2 * (a2 - a0); + float gw = a0 - p0.x * gx - p0.y * gy - p0.z * gz; + + // quadric encodes (eval(pos)-attr)^2; this means that the resulting expansion needs to compute, for example, pos.x * pos.y * K + // since quadrics already encode factors for pos.x * pos.y, we can accumulate almost everything in basic quadric fields + Q.a00 += w * (gx * gx); + Q.a11 += w * (gy * gy); + Q.a22 += w * (gz * gz); + + Q.a10 += w * (gy * gx); + Q.a20 += w * (gz * gx); + Q.a21 += w * (gz * gy); + + Q.b0 += w * (gx * gw); + Q.b1 += w * (gy * gw); + Q.b2 += w * (gz * gw); + + Q.c += w * (gw * gw); + + // the only remaining sum components are ones that depend on attr; these will be addded during error evaluation, see quadricError + Q.gx[k] = w * gx; + Q.gy[k] = w * gy; + Q.gz[k] = w * gz; + Q.gw[k] = w * gw; + +#if TRACE > 2 + printf("attr%d: %e %e %e\n", + k, + (gx * p0.x + gy * p0.y + gz * p0.z + gw - a0), + (gx * p1.x + gy * p1.y + gz * p1.z + gw - a1), + (gx * p2.x + gy * p2.y + gz * p2.z + gw - a2) + ); +#endif + } +} +#endif + static void fillFaceQuadrics(Quadric* vertex_quadrics, const unsigned int* indices, size_t index_count, const Vector3* vertex_positions, const unsigned int* remap) { for (size_t i = 0; i < index_count; i += 3) @@ -580,6 +699,9 @@ static void fillFaceQuadrics(Quadric* vertex_quadrics, const unsigned int* indic Quadric Q; quadricFromTriangle(Q, vertex_positions[i0], vertex_positions[i1], vertex_positions[i2], 1.f); +#if ATTRIBUTES + quadricUpdateAttributes(Q, vertex_positions[i0], vertex_positions[i1], vertex_positions[i2], Q.w); +#endif quadricAdd(vertex_quadrics[remap[i0]], Q); quadricAdd(vertex_quadrics[remap[i1]], Q); quadricAdd(vertex_quadrics[remap[i2]], Q); @@ -1273,13 +1395,19 @@ MESHOPTIMIZER_API unsigned int* meshopt_simplifyDebugLoopBack = 0; #endif size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions_data, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* out_result_error) +{ + return meshopt_simplifyWithAttributes(destination, indices, index_count, vertex_positions_data, vertex_count, vertex_positions_stride, target_index_count, target_error, out_result_error, 0, 0, 0); +} + +size_t meshopt_simplifyWithAttributes(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_data, size_t vertex_count, size_t vertex_stride, size_t target_index_count, float target_error, float* out_result_error, const float* attributes, const float* attribute_weights, size_t attribute_count) { using namespace meshopt; assert(index_count % 3 == 0); - assert(vertex_positions_stride > 0 && vertex_positions_stride <= 256); - assert(vertex_positions_stride % sizeof(float) == 0); + assert(vertex_stride > 0 && vertex_stride <= 256); + assert(vertex_stride % sizeof(float) == 0); assert(target_index_count <= index_count); + assert(attribute_count <= ATTRIBUTES); meshopt_Allocator allocator; @@ -1293,7 +1421,7 @@ size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, // build position remap that maps each vertex to the one with identical position unsigned int* remap = allocator.allocate(vertex_count); unsigned int* wedge = allocator.allocate(vertex_count); - buildPositionRemap(remap, wedge, vertex_positions_data, vertex_count, vertex_positions_stride, allocator); + buildPositionRemap(remap, wedge, vertex_data, vertex_count, vertex_stride, allocator); // classify vertices; vertex kind determines collapse rules, see kCanCollapse unsigned char* vertex_kind = allocator.allocate(vertex_count); @@ -1317,7 +1445,21 @@ size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, #endif Vector3* vertex_positions = allocator.allocate(vertex_count); - rescalePositions(vertex_positions, vertex_positions_data, vertex_count, vertex_positions_stride); + rescalePositions(vertex_positions, vertex_data, vertex_count, vertex_stride); + +#if ATTRIBUTES + for (size_t i = 0; i < vertex_count; ++i) + { + memset(vertex_positions[i].a, 0, sizeof(vertex_positions[i].a)); + + for (size_t k = 0; k < attribute_count; ++k) + { + float a = attributes[i * attribute_count + k]; + + vertex_positions[i].a[k] = a * attribute_weights[k]; + } + } +#endif Quadric* vertex_quadrics = allocator.allocate(vertex_count); memset(vertex_quadrics, 0, vertex_count * sizeof(Quadric)); @@ -1409,7 +1551,9 @@ size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, // result_error is quadratic; we need to remap it back to linear if (out_result_error) + { *out_result_error = sqrtf(result_error); + } return result_count; }