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Diffstat (limited to 'indra/newview/gltf/primitive.cpp')
| -rw-r--r-- | indra/newview/gltf/primitive.cpp | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/indra/newview/gltf/primitive.cpp b/indra/newview/gltf/primitive.cpp new file mode 100644 index 0000000000..bc333aff69 --- /dev/null +++ b/indra/newview/gltf/primitive.cpp @@ -0,0 +1,685 @@ +/** + * @file primitive.cpp + * @brief LL GLTF Implementation + * + * $LicenseInfo:firstyear=2024&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2024, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#include "../llviewerprecompiledheaders.h" + +#include "asset.h" +#include "buffer_util.h" +#include "../llviewershadermgr.h" + +#include "mikktspace/mikktspace.hh" + +#include "meshoptimizer/meshoptimizer.h" + + +using namespace LL::GLTF; +using namespace boost::json; + + +// Mesh data useful for Mikktspace tangent generation (and flat normal generation) +struct MikktMesh +{ + std::vector<LLVector3> p; + std::vector<LLVector3> n; + std::vector<LLVector2> tc; + std::vector<LLVector4> w; + std::vector<LLVector4> t; + std::vector<LLColor4U> c; + std::vector<U64> j; + + // initialize from src primitive and make an unrolled triangle list + // returns false if the Primitive cannot be converted to a triangle list + bool copy(const Primitive* prim) + { + bool indexed = !prim->mIndexArray.empty(); + U32 vert_count = indexed ? prim->mIndexArray.size() : prim->mPositions.size(); + + if (prim->mMode != Primitive::Mode::TRIANGLES) + { + LL_WARNS("GLTF") << "Unsupported primitive mode for conversion to triangles: " << (S32) prim->mMode << LL_ENDL; + return false; + } + + p.resize(vert_count); + n.resize(vert_count); + tc.resize(vert_count); + c.resize(vert_count); + + bool has_normals = !prim->mNormals.empty(); + if (has_normals) + { + n.resize(vert_count); + } + bool has_tangents = !prim->mTangents.empty(); + if (has_tangents) + { + t.resize(vert_count); + } + bool rigged = !prim->mWeights.empty(); + if (rigged) + { + w.resize(vert_count); + j.resize(vert_count); + } + + for (int i = 0; i < vert_count; ++i) + { + U32 idx = indexed ? prim->mIndexArray[i] : i; + + p[i].set(prim->mPositions[idx].getF32ptr()); + tc[i].set(prim->mTexCoords[idx]); + c[i] = prim->mColors[idx]; + + if (has_normals) + { + n[i].set(prim->mNormals[idx].getF32ptr()); + } + + if (rigged) + { + w[i].set(prim->mWeights[idx].getF32ptr()); + j[i] = prim->mJoints[idx]; + } + } + + return true; + } + + void genNormals() + { + U32 tri_count = p.size() / 3; + for (U32 i = 0; i < tri_count; ++i) + { + LLVector3 v0 = p[i * 3]; + LLVector3 v1 = p[i * 3 + 1]; + LLVector3 v2 = p[i * 3 + 2]; + + LLVector3 normal = (v1 - v0) % (v2 - v0); + normal.normalize(); + + n[i * 3] = normal; + n[i * 3 + 1] = normal; + n[i * 3 + 2] = normal; + } + } + + void genTangents() + { + t.resize(p.size()); + mikk::Mikktspace ctx(*this); + ctx.genTangSpace(); + } + + // write to target primitive as an indexed triangle list + // Only modifies runtime data, does not modify the original GLTF data + void write(Primitive* prim) const + { + //re-weld + meshopt_Stream mos[] = + { + { &p[0], sizeof(LLVector3), sizeof(LLVector3) }, + { &n[0], sizeof(LLVector3), sizeof(LLVector3) }, + { &t[0], sizeof(LLVector4), sizeof(LLVector4) }, + { &tc[0], sizeof(LLVector2), sizeof(LLVector2) }, + { &c[0], sizeof(LLColor4U), sizeof(LLColor4U) }, + { w.empty() ? nullptr : &w[0], sizeof(LLVector4), sizeof(LLVector4) }, + { j.empty() ? nullptr : &j[0], sizeof(U64), sizeof(U64) } + }; + + std::vector<U32> remap; + remap.resize(p.size()); + + U32 stream_count = w.empty() ? 5 : 7; + + size_t vert_count = meshopt_generateVertexRemapMulti(&remap[0], nullptr, p.size(), p.size(), mos, stream_count); + + prim->mTexCoords.resize(vert_count); + prim->mNormals.resize(vert_count); + prim->mTangents.resize(vert_count); + prim->mPositions.resize(vert_count); + prim->mColors.resize(vert_count); + if (!w.empty()) + { + prim->mWeights.resize(vert_count); + prim->mJoints.resize(vert_count); + } + + prim->mIndexArray.resize(remap.size()); + + for (int i = 0; i < remap.size(); ++i) + { + U32 src_idx = i; + U32 dst_idx = remap[i]; + + prim->mIndexArray[i] = dst_idx; + + prim->mPositions[dst_idx].load3(p[src_idx].mV); + prim->mNormals[dst_idx].load3(n[src_idx].mV); + prim->mTexCoords[dst_idx] = tc[src_idx]; + prim->mTangents[dst_idx].loadua(t[src_idx].mV); + prim->mColors[dst_idx] = c[src_idx]; + + if (!w.empty()) + { + prim->mWeights[dst_idx].loadua(w[src_idx].mV); + prim->mJoints[dst_idx] = j[src_idx]; + } + } + + prim->mGLMode = LLRender::TRIANGLES; + } + + uint32_t GetNumFaces() + { + return uint32_t(p.size()/3); + } + + uint32_t GetNumVerticesOfFace(const uint32_t face_num) + { + return 3; + } + + mikk::float3 GetPosition(const uint32_t face_num, const uint32_t vert_num) + { + F32* v = p[face_num * 3 + vert_num].mV; + return mikk::float3(v); + } + + mikk::float3 GetTexCoord(const uint32_t face_num, const uint32_t vert_num) + { + F32* uv = tc[face_num * 3 + vert_num].mV; + return mikk::float3(uv[0], uv[1], 1.0f); + } + + mikk::float3 GetNormal(const uint32_t face_num, const uint32_t vert_num) + { + F32* normal = n[face_num * 3 + vert_num].mV; + return mikk::float3(normal); + } + + void SetTangentSpace(const uint32_t face_num, const uint32_t vert_num, mikk::float3 T, bool orientation) + { + S32 i = face_num * 3 + vert_num; + t[i].set(T.x, T.y, T.z, orientation ? 1.0f : -1.0f); + } +}; + + +bool Primitive::prep(Asset& asset) +{ + // allocate vertex buffer + // We diverge from the intent of the GLTF format here to work with our existing render pipeline + // GLTF wants us to copy the buffer views into GPU storage as is and build render commands that source that data. + // For our engine, though, it's better to rearrange the buffers at load time into a layout that's more consistent. + // The GLTF native approach undoubtedly works well if you can count on VAOs, but VAOs perform much worse with our scenes. + + // load vertex data + for (auto& it : mAttributes) + { + const std::string& attribName = it.first; + Accessor& accessor = asset.mAccessors[it.second]; + + // load vertex data + if (attribName == "POSITION") + { + copy(asset, accessor, mPositions); + } + else if (attribName == "NORMAL") + { + copy(asset, accessor, mNormals); + } + else if (attribName == "TANGENT") + { + copy(asset, accessor, mTangents); + } + else if (attribName == "COLOR_0") + { + copy(asset, accessor, mColors); + } + else if (attribName == "TEXCOORD_0") + { + copy(asset, accessor, mTexCoords); + } + else if (attribName == "JOINTS_0") + { + copy(asset, accessor, mJoints); + } + else if (attribName == "WEIGHTS_0") + { + copy(asset, accessor, mWeights); + } + } + + // copy index buffer + if (mIndices != INVALID_INDEX) + { + Accessor& accessor = asset.mAccessors[mIndices]; + copy(asset, accessor, mIndexArray); + + for (auto& idx : mIndexArray) + { + if (idx >= mPositions.size()) + { + LL_WARNS("GLTF") << "Invalid index array" << LL_ENDL; + return false; + } + } + } + + U32 mask = LLVertexBuffer::MAP_VERTEX; + + if (!mWeights.empty()) + { + mask |= LLVertexBuffer::MAP_WEIGHT4; + mask |= LLVertexBuffer::MAP_JOINT; + } + + if (mTexCoords.empty()) + { + mTexCoords.resize(mPositions.size()); + } + + // TODO: support more than one texcoord set (or no texcoords) + mask |= LLVertexBuffer::MAP_TEXCOORD0; + + if (mColors.empty()) + { + mColors.resize(mPositions.size(), LLColor4U::white); + } + + // TODO: support colorless vertex buffers + mask |= LLVertexBuffer::MAP_COLOR; + + mShaderVariant = 0; + + bool unlit = false; + + // bake material basecolor into color array + if (mMaterial != INVALID_INDEX) + { + const Material& material = asset.mMaterials[mMaterial]; + LLColor4 baseColor(glm::value_ptr(material.mPbrMetallicRoughness.mBaseColorFactor)); + for (auto& dst : mColors) + { + dst = LLColor4U(baseColor * LLColor4(dst)); + } + + if (material.mUnlit.mPresent) + { // material uses KHR_materials_unlit + mShaderVariant |= LLGLSLShader::GLTFVariant::UNLIT; + unlit = true; + } + } + + if (mNormals.empty() && !unlit) + { + mTangents.clear(); + + if (mMode == Mode::POINTS || mMode == Mode::LINES || mMode == Mode::LINE_LOOP || mMode == Mode::LINE_STRIP) + { //no normals and no surfaces, this primitive is unlit + mTangents.clear(); + mShaderVariant |= LLGLSLShader::GLTFVariant::UNLIT; + unlit = true; + } + else + { + // unroll into non-indexed array of flat shaded triangles + MikktMesh data; + if (!data.copy(this)) + { + return false; + } + + data.genNormals(); + data.genTangents(); + data.write(this); + } + } + + if (mTangents.empty() && !unlit) + { // NOTE: must be done last because tangent generation rewrites the other arrays + // adapted from usage of Mikktspace in llvolume.cpp + if (mMode == Mode::POINTS || mMode == Mode::LINES || mMode == Mode::LINE_LOOP || mMode == Mode::LINE_STRIP) + { + // for points and lines, just make sure tangent is perpendicular to normal + mTangents.resize(mNormals.size()); + LLVector4a up(0.f, 0.f, 1.f, 0.f); + LLVector4a left(1.f, 0.f, 0.f, 0.f); + for (U32 i = 0; i < mNormals.size(); ++i) + { + if (fabsf(mNormals[i].getF32ptr()[2]) < 0.999f) + { + mTangents[i] = up.cross3(mNormals[i]); + } + else + { + mTangents[i] = left.cross3(mNormals[i]); + } + + mTangents[i].getF32ptr()[3] = 1.f; + } + } + else + { + MikktMesh data; + if (!data.copy(this)) + { + return false; + } + + data.genTangents(); + data.write(this); + } + } + + if (!mNormals.empty()) + { + mask |= LLVertexBuffer::MAP_NORMAL; + } + + if (!mTangents.empty()) + { + mask |= LLVertexBuffer::MAP_TANGENT; + } + + if (LLGLSLShader::sCurBoundShaderPtr == nullptr) + { // make sure a shader is bound to satisfy mVertexBuffer->setBuffer + gDebugProgram.bind(); + } + + mVertexBuffer = new LLVertexBuffer(mask); + mVertexBuffer->allocateBuffer(mPositions.size(), mIndexArray.size() * 2); // double the size of the index buffer for 32-bit indices + + mVertexBuffer->setBuffer(); + mVertexBuffer->setPositionData(mPositions.data()); + mVertexBuffer->setColorData(mColors.data()); + + if (!mNormals.empty()) + { + mVertexBuffer->setNormalData(mNormals.data()); + } + if (!mTangents.empty()) + { + mVertexBuffer->setTangentData(mTangents.data()); + } + + if (!mWeights.empty()) + { + mShaderVariant |= LLGLSLShader::GLTFVariant::RIGGED; + mVertexBuffer->setWeight4Data(mWeights.data()); + mVertexBuffer->setJointData(mJoints.data()); + } + + // flip texcoord y, upload, then flip back (keep the off-spec data in vram only) + for (auto& tc : mTexCoords) + { + tc[1] = 1.f - tc[1]; + } + mVertexBuffer->setTexCoordData(mTexCoords.data()); + for (auto& tc : mTexCoords) + { + tc[1] = 1.f - tc[1]; + } + + if (!mIndexArray.empty()) + { + mVertexBuffer->setIndexData(mIndexArray.data()); + } + + createOctree(); + + mVertexBuffer->unbind(); + + Material& material = asset.mMaterials[mMaterial]; + if (material.mAlphaMode == Material::AlphaMode::BLEND) + { + mShaderVariant |= LLGLSLShader::GLTFVariant::ALPHA_BLEND; + } + + return true; +} + +void initOctreeTriangle(LLVolumeTriangle* tri, F32 scaler, S32 i0, S32 i1, S32 i2, const LLVector4a& v0, const LLVector4a& v1, const LLVector4a& v2) +{ + //store pointers to vertex data + tri->mV[0] = &v0; + tri->mV[1] = &v1; + tri->mV[2] = &v2; + + //store indices + tri->mIndex[0] = i0; + tri->mIndex[1] = i1; + tri->mIndex[2] = i2; + + //get minimum point + LLVector4a min = v0; + min.setMin(min, v1); + min.setMin(min, v2); + + //get maximum point + LLVector4a max = v0; + max.setMax(max, v1); + max.setMax(max, v2); + + //compute center + LLVector4a center; + center.setAdd(min, max); + center.mul(0.5f); + + tri->mPositionGroup = center; + + //compute "radius" + LLVector4a size; + size.setSub(max, min); + + tri->mRadius = size.getLength3().getF32() * scaler; +} + +void Primitive::createOctree() +{ + // create octree + mOctree = new LLVolumeOctree(); + + F32 scaler = 0.25f; + + if (mMode == Mode::TRIANGLES) + { + const U32 num_triangles = mVertexBuffer->getNumIndices() / 3; + // Initialize all the triangles we need + mOctreeTriangles.resize(num_triangles); + + for (U32 triangle_index = 0; triangle_index < num_triangles; ++triangle_index) + { //for each triangle + const U32 index = triangle_index * 3; + LLVolumeTriangle* tri = &mOctreeTriangles[triangle_index]; + S32 i0 = mIndexArray[index]; + S32 i1 = mIndexArray[index + 1]; + S32 i2 = mIndexArray[index + 2]; + + const LLVector4a& v0 = mPositions[i0]; + const LLVector4a& v1 = mPositions[i1]; + const LLVector4a& v2 = mPositions[i2]; + + initOctreeTriangle(tri, scaler, i0, i1, i2, v0, v1, v2); + + //insert + mOctree->insert(tri); + } + } + else if (mMode == Mode::TRIANGLE_STRIP) + { + const U32 num_triangles = mVertexBuffer->getNumIndices() - 2; + // Initialize all the triangles we need + mOctreeTriangles.resize(num_triangles); + + for (U32 triangle_index = 0; triangle_index < num_triangles; ++triangle_index) + { //for each triangle + const U32 index = triangle_index + 2; + LLVolumeTriangle* tri = &mOctreeTriangles[triangle_index]; + S32 i0 = mIndexArray[index]; + S32 i1 = mIndexArray[index - 1]; + S32 i2 = mIndexArray[index - 2]; + + const LLVector4a& v0 = mPositions[i0]; + const LLVector4a& v1 = mPositions[i1]; + const LLVector4a& v2 = mPositions[i2]; + + initOctreeTriangle(tri, scaler, i0, i1, i2, v0, v1, v2); + + //insert + mOctree->insert(tri); + } + } + else if (mMode == Mode::TRIANGLE_FAN) + { + const U32 num_triangles = mVertexBuffer->getNumIndices() - 2; + // Initialize all the triangles we need + mOctreeTriangles.resize(num_triangles); + + for (U32 triangle_index = 0; triangle_index < num_triangles; ++triangle_index) + { //for each triangle + const U32 index = triangle_index + 2; + LLVolumeTriangle* tri = &mOctreeTriangles[triangle_index]; + S32 i0 = mIndexArray[0]; + S32 i1 = mIndexArray[index - 1]; + S32 i2 = mIndexArray[index - 2]; + + const LLVector4a& v0 = mPositions[i0]; + const LLVector4a& v1 = mPositions[i1]; + const LLVector4a& v2 = mPositions[i2]; + + initOctreeTriangle(tri, scaler, i0, i1, i2, v0, v1, v2); + + //insert + mOctree->insert(tri); + } + } + else if (mMode == Mode::POINTS || + mMode == Mode::LINES || + mMode == Mode::LINE_LOOP || + mMode == Mode::LINE_STRIP) + { + // nothing to do, no volume... maybe add some collision geometry around these primitive types? + } + + else + { + LL_ERRS() << "Unsupported Primitive mode" << LL_ENDL; + } + + //remove unneeded octree layers + while (!mOctree->balance()) {} + + //calculate AABB for each node + LLVolumeOctreeRebound rebound; + rebound.traverse(mOctree); +} + +const LLVolumeTriangle* Primitive::lineSegmentIntersect(const LLVector4a& start, const LLVector4a& end, + LLVector4a* intersection, LLVector2* tex_coord, LLVector4a* normal, LLVector4a* tangent_out) +{ + if (mOctree.isNull()) + { + return nullptr; + } + + LLVector4a dir; + dir.setSub(end, start); + + F32 closest_t = 2.f; // must be larger than 1 + + //create a proxy LLVolumeFace for the raycast + LLVolumeFace face; + face.mPositions = mPositions.data(); + face.mTexCoords = mTexCoords.data(); + face.mNormals = mNormals.data(); + face.mTangents = mTangents.data(); + face.mIndices = nullptr; // unreferenced + + face.mNumIndices = mIndexArray.size(); + face.mNumVertices = mPositions.size(); + + LLOctreeTriangleRayIntersect intersect(start, dir, &face, &closest_t, intersection, tex_coord, normal, tangent_out); + intersect.traverse(mOctree); + + // null out proxy data so it doesn't get freed + face.mPositions = face.mNormals = face.mTangents = nullptr; + face.mIndices = nullptr; + face.mTexCoords = nullptr; + + return intersect.mHitTriangle; +} + +Primitive::~Primitive() +{ + mOctree = nullptr; +} + +LLRender::eGeomModes gltf_mode_to_gl_mode(Primitive::Mode mode) +{ + switch (mode) + { + case Primitive::Mode::POINTS: + return LLRender::POINTS; + case Primitive::Mode::LINES: + return LLRender::LINES; + case Primitive::Mode::LINE_LOOP: + return LLRender::LINE_LOOP; + case Primitive::Mode::LINE_STRIP: + return LLRender::LINE_STRIP; + case Primitive::Mode::TRIANGLES: + return LLRender::TRIANGLES; + case Primitive::Mode::TRIANGLE_STRIP: + return LLRender::TRIANGLE_STRIP; + case Primitive::Mode::TRIANGLE_FAN: + return LLRender::TRIANGLE_FAN; + default: + return LLRender::TRIANGLES; + } +} + +void Primitive::serialize(boost::json::object& dst) const +{ + write(mMaterial, "material", dst, -1); + write(mMode, "mode", dst, Primitive::Mode::TRIANGLES); + write(mIndices, "indices", dst, INVALID_INDEX); + write(mAttributes, "attributes", dst); +} + +const Primitive& Primitive::operator=(const Value& src) +{ + if (src.is_object()) + { + copy(src, "material", mMaterial); + copy(src, "mode", mMode); + copy(src, "indices", mIndices); + copy(src, "attributes", mAttributes); + + mGLMode = gltf_mode_to_gl_mode(mMode); + } + return *this; +} + |