Torque3D/Engine/lib/assimp/code/AssetLib/Ply/PlyLoader.cpp

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/** @file  PlyLoader.cpp
 *  @brief Implementation of the PLY importer class
 */

#ifndef ASSIMP_BUILD_NO_PLY_IMPORTER

// internal headers
#include "PlyLoader.h"

// standard headers
#include <assimp/IOStreamBuffer.h>
#include <assimp/importerdesc.h>
#include <assimp/scene.h>
#include <assimp/IOSystem.hpp>

// other headers
#include <memory>

namespace Assimp {

    // ------------------------------------------------------------------------------------------------
    static constexpr ai_uint NotSet = 0xFFFFFFFF;

    static constexpr aiImporterDesc desc = {
        "Stanford Polygon Library (PLY) Importer",
        "",
        "",
        "",
        aiImporterFlags_SupportBinaryFlavour | aiImporterFlags_SupportTextFlavour,
        0,
        0,
        0,
        0,
        "ply"
    };

    namespace { // Internal stuff
        // ------------------------------------------------------------------------------------------------
        // Checks that property index is within range
        template <class T>
        const T &GetProperty(const std::vector<T> &props, int idx) {
            if (static_cast<size_t>(idx) >= props.size()) {
                throw DeadlyImportError("Invalid .ply file: Property index is out of range.");
            }

            return props[idx];
        }

        // ------------------------------------------------------------------------------------------------
        bool isBigEndian(const char *szMe) {
            ai_assert(nullptr != szMe);

            // binary_little_endian
            // binary_big_endian
            bool isBigEndian{ false };
    #if (defined AI_BUILD_BIG_ENDIAN)
            if ('l' == *szMe || 'L' == *szMe) {
                isBigEndian = true;
            }
    #else
            if ('b' == *szMe || 'B' == *szMe) {
                isBigEndian = true;
            }
    #endif // ! AI_BUILD_BIG_ENDIAN

            return isBigEndian;
        }

        // ------------------------------------------------------------------------------------------------
        // Convert a color component to [0...1]
        ai_real NormalizeColorValue(PropertyInstance::ValueUnion val, EDataType eType) {
            switch (eType) {
                case EDT_Float:
                    return val.fFloat;
                case EDT_Double:
                    return static_cast<ai_real>(val.fDouble);
                case EDT_UChar:
                    return static_cast<ai_real>(val.iUInt) / static_cast<ai_real>(0xFF);
                case EDT_Char:
                    return static_cast<ai_real>(val.iInt + (0xFF / 2)) / static_cast<ai_real>(0xFF);
                case EDT_UShort:
                    return static_cast<ai_real>(val.iUInt) / static_cast<ai_real>(0xFFFF);
                case EDT_Short:
                    return static_cast<ai_real>(val.iInt + (0xFFFF / 2)) / static_cast<ai_real>(0xFFFF);
                case EDT_UInt:
                    return static_cast<ai_real>(val.iUInt) / static_cast<ai_real>(0xFFFF);
                case EDT_Int:
                    return (static_cast<ai_real>(val.iInt) / static_cast<ai_real>(0xFF)) + 0.5f;
                default:
                    break;
            }

            return 0.0f;
        }

        // ------------------------------------------------------------------------------------------------
        // Get a RGBA color in [0...1] range
        void GetMaterialColor(const std::vector<PLY::PropertyInstance> &avList, unsigned int positions[4], EDataType types[4],
                aiColor4D *clrOut) {
            ai_assert(nullptr != clrOut);

            if (NotSet == positions[0]) {
                clrOut->r = 0.0f;
            } else {
                clrOut->r = NormalizeColorValue(GetProperty(avList, positions[0]).avList.front(), types[0]);
            }

            if (NotSet == positions[1]) {
                clrOut->g = 0.0f;
            } else {
                clrOut->g = NormalizeColorValue(GetProperty(avList, positions[1]).avList.front(), types[1]);
            }

            if (NotSet == positions[2]) {
                clrOut->b = 0.0f;
            } else {
                clrOut->b = NormalizeColorValue(GetProperty(avList, positions[2]).avList.front(), types[2]);
            }

            // assume 1.0 for the alpha channel ifit is not set
            if (NotSet == positions[3]) {
                clrOut->a = 1.0f;
            } else {
                clrOut->a = NormalizeColorValue(GetProperty(avList, positions[3]).avList.front(), types[3]);
            }
        }

    } // namespace

    // ------------------------------------------------------------------------------------------------
    PLYImporter::~PLYImporter() {
        delete mGeneratedMesh;
    }

    // ------------------------------------------------------------------------------------------------
    // Returns whether the class can handle the format of the given file.
    bool PLYImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool) const {
        static const char *tokens[] = { "ply" };
        return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens));
    }

    // ------------------------------------------------------------------------------------------------
    const aiImporterDesc *PLYImporter::GetInfo() const {
        return &desc;
    }

    // ------------------------------------------------------------------------------------------------
    // Imports the given file into the given scene structure.
    void PLYImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler) {
        const std::string mode = "rb";
        std::unique_ptr<IOStream> fileStream(pIOHandler->Open(pFile, mode));
        if (!fileStream) {
            throw DeadlyImportError("Failed to open file ", pFile, ".");
        }

        // Get the file-size
        const size_t fileSize = fileStream->FileSize();
        if (0 == fileSize) {
            throw DeadlyImportError("File ", pFile, " is empty.");
        }

        IOStreamBuffer<char> streamedBuffer(1024 * 1024);
        streamedBuffer.open(fileStream.get());

        // the beginning of the file must be PLY - magic, magic
        std::vector<char> headerCheck;
        streamedBuffer.getNextLine(headerCheck);

        if ((headerCheck.size() < 3) ||
                (headerCheck[0] != 'P' && headerCheck[0] != 'p') ||
                (headerCheck[1] != 'L' && headerCheck[1] != 'l') ||
                (headerCheck[2] != 'Y' && headerCheck[2] != 'y')) {
            streamedBuffer.close();
            throw DeadlyImportError("Invalid .ply file: Incorrect magic number (expected 'ply' or 'PLY').");
        }

        std::vector<char> mBuffer2;
        streamedBuffer.getNextLine(mBuffer2);
        mBuffer = (unsigned char *)&mBuffer2[0];

        auto szMe = (char *)&this->mBuffer[0];
        const char *end = &mBuffer2[0] + mBuffer2.size();
        SkipSpacesAndLineEnd(szMe, (const char **)&szMe, end);

        // determine the format of the file data and construct the aiMesh
        DOM sPlyDom;
        this->pcDOM = &sPlyDom;

        if (TokenMatch(szMe, "format", 6)) {
            if (TokenMatch(szMe, "ascii", 5)) {
                SkipLine(szMe, (const char **)&szMe, end);
                if (!DOM::ParseInstance(streamedBuffer, &sPlyDom, this)) {
                    if (mGeneratedMesh != nullptr) {
                        delete (mGeneratedMesh);
                        mGeneratedMesh = nullptr;
                    }

                    streamedBuffer.close();
                    throw DeadlyImportError("Invalid .ply file: Unable to build DOM (#1)");
                }
            } else if (!strncmp(szMe, "binary_", 7)) {
                szMe += 7;

                // skip the line, parse the rest of the header and build the DOM
                if (const bool bIsBE = isBigEndian(szMe); !PLY::DOM::ParseInstanceBinary(streamedBuffer, &sPlyDom, this, bIsBE)) {
                    if (mGeneratedMesh != nullptr) {
                        delete (mGeneratedMesh);
                        mGeneratedMesh = nullptr;
                    }

                    streamedBuffer.close();
                    throw DeadlyImportError("Invalid .ply file: Unable to build DOM (#2)");
                }
            } else {
                if (mGeneratedMesh != nullptr) {
                    delete mGeneratedMesh;
                    mGeneratedMesh = nullptr;
                }

                streamedBuffer.close();
                throw DeadlyImportError("Invalid .ply file: Unknown file format");
            }
        } else {
            AI_DEBUG_INVALIDATE_PTR(this->mBuffer);
            if (mGeneratedMesh != nullptr) {
                delete (mGeneratedMesh);
                mGeneratedMesh = nullptr;
            }

            streamedBuffer.close();
            throw DeadlyImportError("Invalid .ply file: Missing format specification");
        }

        // free the file buffer
        streamedBuffer.close();

        if (mGeneratedMesh == nullptr) {
            throw DeadlyImportError("Invalid .ply file: Unable to extract mesh data ");
        }

        // if no face list is existing we assume that the vertex
        // list is containing a list of points
        bool pointsOnly = mGeneratedMesh->mFaces == nullptr ? true : false;
        if (pointsOnly) {
            mGeneratedMesh->mPrimitiveTypes = aiPrimitiveType::aiPrimitiveType_POINT;
        }

        // now load a list of all materials
        std::vector<aiMaterial *> avMaterials;
        std::string defaultTexture;
        LoadMaterial(&avMaterials, defaultTexture, pointsOnly);

        // now generate the output scene object. Fill the material list
        pScene->mNumMaterials = static_cast<unsigned int>(avMaterials.size());
        pScene->mMaterials = new aiMaterial *[pScene->mNumMaterials];
        for (unsigned int i = 0; i < pScene->mNumMaterials; ++i) {
            pScene->mMaterials[i] = avMaterials[i];
        }

        // fill the mesh list
        pScene->mNumMeshes = 1;
        pScene->mMeshes = new aiMesh *[pScene->mNumMeshes];
        pScene->mMeshes[0] = mGeneratedMesh;

        // Move the mesh ownership into the scene instance
        mGeneratedMesh = nullptr;

        // generate a simple node structure
        pScene->mRootNode = new aiNode();
        pScene->mRootNode->mNumMeshes = pScene->mNumMeshes;
        pScene->mRootNode->mMeshes = new unsigned int[pScene->mNumMeshes];

        for (unsigned int i = 0; i < pScene->mRootNode->mNumMeshes; ++i) {
            pScene->mRootNode->mMeshes[i] = i;
        }
    }

    void PLYImporter::LoadVertex(const Element *pcElement, const ElementInstance *instElement, unsigned int pos) {
        ai_assert(nullptr != pcElement);
        ai_assert(nullptr != instElement);

        ai_uint aiPositions[3] = { NotSet, NotSet, NotSet };
        EDataType aiTypes[3] = { EDT_Char, EDT_Char, EDT_Char };

        ai_uint aiNormal[3] = { NotSet, NotSet, NotSet };
        EDataType aiNormalTypes[3] = { EDT_Char, EDT_Char, EDT_Char };

        unsigned int aiColors[4] = { NotSet, NotSet, NotSet, NotSet };
        EDataType aiColorsTypes[4] = { EDT_Char, EDT_Char, EDT_Char, EDT_Char };

        unsigned int aiTexcoord[2] = { NotSet, NotSet };
        EDataType aiTexcoordTypes[2] = { EDT_Char, EDT_Char };

        // now check whether which normal components are available
        unsigned int _a(0), cnt(0);
        for (auto a = pcElement->alProperties.begin(); a != pcElement->alProperties.end(); ++a, ++_a) {
            if (a->bIsList) {
                continue;
            }

            // Positions
            if (EST_XCoord == a->Semantic) {
                ++cnt;
                aiPositions[0] = _a;
                aiTypes[0] = a->eType;
            } else if (EST_YCoord == a->Semantic) {
                ++cnt;
                aiPositions[1] = _a;
                aiTypes[1] = a->eType;
            } else if (EST_ZCoord == a->Semantic) {
                ++cnt;
                aiPositions[2] = _a;
                aiTypes[2] = a->eType;
            } else if (EST_XNormal == a->Semantic) {
                // Normals
                ++cnt;
                aiNormal[0] = _a;
                aiNormalTypes[0] = a->eType;
            } else if (EST_YNormal == a->Semantic) {
                ++cnt;
                aiNormal[1] = _a;
                aiNormalTypes[1] = a->eType;
            } else if (EST_ZNormal == a->Semantic) {
                ++cnt;
                aiNormal[2] = _a;
                aiNormalTypes[2] = a->eType;
            } else if (EST_Red == a->Semantic) {
                // Colors
                ++cnt;
                aiColors[0] = _a;
                aiColorsTypes[0] = a->eType;
            } else if (EST_Green == a->Semantic) {
                ++cnt;
                aiColors[1] = _a;
                aiColorsTypes[1] = a->eType;
            } else if (EST_Blue == a->Semantic) {
                ++cnt;
                aiColors[2] = _a;
                aiColorsTypes[2] = a->eType;
            } else if (EST_Alpha == a->Semantic) {
                ++cnt;
                aiColors[3] = _a;
                aiColorsTypes[3] = a->eType;
            } else if (EST_UTextureCoord == a->Semantic) {
                // Texture coordinates
                ++cnt;
                aiTexcoord[0] = _a;
                aiTexcoordTypes[0] = a->eType;
            } else if (EST_VTextureCoord == a->Semantic) {
                ++cnt;
                aiTexcoord[1] = _a;
                aiTexcoordTypes[1] = a->eType;
            }
        }

        // check whether we have a valid source for the vertex data
        if (0 != cnt) {
            // Position
            aiVector3D vOut;
            if (NotSet != aiPositions[0]) {
                vOut.x = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiPositions[0]).avList.front(), aiTypes[0]);
            }

            if (NotSet != aiPositions[1]) {
                vOut.y = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiPositions[1]).avList.front(), aiTypes[1]);
            }

            if (NotSet != aiPositions[2]) {
                vOut.z = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiPositions[2]).avList.front(), aiTypes[2]);
            }

            // Normals
            aiVector3D nOut;
            bool haveNormal = false;
            if (NotSet != aiNormal[0]) {
                nOut.x = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiNormal[0]).avList.front(), aiNormalTypes[0]);
                haveNormal = true;
            }

            if (NotSet != aiNormal[1]) {
                nOut.y = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiNormal[1]).avList.front(), aiNormalTypes[1]);
                haveNormal = true;
            }

            if (NotSet != aiNormal[2]) {
                nOut.z = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiNormal[2]).avList.front(), aiNormalTypes[2]);
                haveNormal = true;
            }

            // Colors
            aiColor4D cOut;
            bool haveColor = false;
            if (NotSet != aiColors[0]) {
                cOut.r = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                    aiColors[0])
                                                    .avList.front(),
                        aiColorsTypes[0]);
                haveColor = true;
            }

            if (NotSet != aiColors[1]) {
                cOut.g = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                    aiColors[1])
                                                    .avList.front(),
                        aiColorsTypes[1]);
                haveColor = true;
            }

            if (NotSet != aiColors[2]) {
                cOut.b = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                    aiColors[2])
                                                    .avList.front(),
                        aiColorsTypes[2]);
                haveColor = true;
            }

            // assume 1.0 for the alpha channel if it is not set
            if (NotSet == aiColors[3]) {
                cOut.a = 1.0;
            } else {
                cOut.a = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                    aiColors[3])
                                                    .avList.front(),
                        aiColorsTypes[3]);

                haveColor = true;
            }

            // Texture coordinates
            aiVector3D tOut;
            tOut.z = 0;
            bool haveTextureCoords = false;
            if (NotSet != aiTexcoord[0]) {
                tOut.x = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiTexcoord[0]).avList.front(), aiTexcoordTypes[0]);
                haveTextureCoords = true;
            }

            if (NotSet != aiTexcoord[1]) {
                tOut.y = PropertyInstance::ConvertTo<ai_real>(
                        GetProperty(instElement->alProperties, aiTexcoord[1]).avList.front(), aiTexcoordTypes[1]);
                haveTextureCoords = true;
            }

            // create aiMesh if needed
            if (nullptr == mGeneratedMesh) {
                mGeneratedMesh = new aiMesh();
                mGeneratedMesh->mMaterialIndex = 0;
            }

            if (nullptr == mGeneratedMesh->mVertices) {
                mGeneratedMesh->mNumVertices = pcElement->NumOccur;
                mGeneratedMesh->mVertices = new aiVector3D[mGeneratedMesh->mNumVertices];
            }
            if (pos >= mGeneratedMesh->mNumVertices) {
                throw DeadlyImportError("Invalid .ply file: Too many vertices");
            }

            mGeneratedMesh->mVertices[pos] = vOut;

            if (haveNormal) {
                if (nullptr == mGeneratedMesh->mNormals)
                    mGeneratedMesh->mNormals = new aiVector3D[mGeneratedMesh->mNumVertices];
                mGeneratedMesh->mNormals[pos] = nOut;
            }

            if (haveColor) {
                if (nullptr == mGeneratedMesh->mColors[0])
                    mGeneratedMesh->mColors[0] = new aiColor4D[mGeneratedMesh->mNumVertices];
                mGeneratedMesh->mColors[0][pos] = cOut;
            }

            if (haveTextureCoords) {
                if (nullptr == mGeneratedMesh->mTextureCoords[0]) {
                    mGeneratedMesh->mNumUVComponents[0] = 2;
                    mGeneratedMesh->mTextureCoords[0] = new aiVector3D[mGeneratedMesh->mNumVertices];
                }
                mGeneratedMesh->mTextureCoords[0][pos] = tOut;
            }
        }
    }

    // ------------------------------------------------------------------------------------------------
    // Try to extract proper faces from the PLY DOM
    void PLYImporter::LoadFace(const Element *pcElement, const ElementInstance *instElement,
            unsigned int pos) {
        ai_assert(nullptr != pcElement);
        ai_assert(nullptr != instElement);

        if (mGeneratedMesh == nullptr) {
            throw DeadlyImportError("Invalid .ply file: Vertices should be declared before faces");
        }

        bool bOne = false;

        // index of the vertex index list
        unsigned int iProperty = NotSet;
        EDataType eType = EDT_Char;
        bool bIsTriStrip = false;

        // texture coordinates
        unsigned int iTextureCoord = NotSet;
        EDataType eType3 = EDT_Char;

        // face = unique number of vertex indices
        if (EEST_Face == pcElement->eSemantic) {
            unsigned int _a = 0;
            for (std::vector<Property>::const_iterator a = pcElement->alProperties.begin();
                    a != pcElement->alProperties.end(); ++a, ++_a) {
                if (EST_VertexIndex == a->Semantic) {
                    // must be a dynamic list!
                    if (!a->bIsList) {
                        continue;
                    }

                    iProperty = _a;
                    bOne = true;
                    eType = a->eType;
                } else if (EST_TextureCoordinates == a->Semantic) {
                    // must be a dynamic list!
                    if (!a->bIsList) {
                        continue;
                    }
                    iTextureCoord = _a;
                    bOne = true;
                    eType3 = a->eType;
                }
            }
        }
        // triangle strip
        // TODO: material index support???
        else if (EEST_TriStrip == pcElement->eSemantic) {
            unsigned int _a = 0;
            for (auto a = pcElement->alProperties.begin(); a != pcElement->alProperties.end(); ++a, ++_a) {
                // must be a dynamic list!
                if (!a->bIsList) {
                    continue;
                }
                iProperty = _a;
                bOne = true;
                bIsTriStrip = true;
                eType = a->eType;
                break;
            }
        }

        // check whether we have at least one per-face information set
        if (bOne) {
            if (mGeneratedMesh->mFaces == nullptr) {
                mGeneratedMesh->mNumFaces = pcElement->NumOccur;
                mGeneratedMesh->mFaces = new aiFace[mGeneratedMesh->mNumFaces];
            } else {
                if (mGeneratedMesh->mNumFaces < pcElement->NumOccur) {
                    throw DeadlyImportError("Invalid .ply file: Too many faces");
                }
            }

            if (!bIsTriStrip) {
                // parse the list of vertex indices
                if (NotSet != iProperty) {
                    const unsigned int iNum = static_cast<unsigned int>(GetProperty(instElement->alProperties, iProperty).avList.size());
                    mGeneratedMesh->mFaces[pos].mNumIndices = iNum;
                    mGeneratedMesh->mFaces[pos].mIndices = new unsigned int[iNum];

                    std::vector<PropertyInstance::ValueUnion>::const_iterator p =
                            GetProperty(instElement->alProperties, iProperty).avList.begin();

                    for (unsigned int a = 0; a < iNum; ++a, ++p) {
                        mGeneratedMesh->mFaces[pos].mIndices[a] = PropertyInstance::ConvertTo<unsigned int>(*p, eType);
                    }
                }

                if (NotSet != iTextureCoord) {
                    const auto iNum = static_cast<unsigned int>(GetProperty(instElement->alProperties, iTextureCoord).avList.size());

                    // should be 6 coords
                    auto p = GetProperty(instElement->alProperties, iTextureCoord).avList.begin();
                    if ((iNum / 3) == 2) { // X Y coord
                        for (unsigned int a = 0; a < iNum; ++a, ++p) {
                            unsigned int vindex = mGeneratedMesh->mFaces[pos].mIndices[a / 2];
                            if (vindex < mGeneratedMesh->mNumVertices) {
                                if (mGeneratedMesh->mTextureCoords[0] == nullptr) {
                                    mGeneratedMesh->mNumUVComponents[0] = 2;
                                    mGeneratedMesh->mTextureCoords[0] = new aiVector3D[mGeneratedMesh->mNumVertices];
                                }

                                if (a % 2 == 0) {
                                    mGeneratedMesh->mTextureCoords[0][vindex].x = PLY::PropertyInstance::ConvertTo<ai_real>(*p, eType3);
                                } else {
                                    mGeneratedMesh->mTextureCoords[0][vindex].y = PLY::PropertyInstance::ConvertTo<ai_real>(*p, eType3);
                                }

                                mGeneratedMesh->mTextureCoords[0][vindex].z = 0;
                            }
                        }
                    }
                }
            } else { // triangle strips
                // normally we have only one triangle strip instance where
                // a value of -1 indicates a restart of the strip
                createFromeTriStrip(instElement, iProperty, eType);
            }
        }
    }

    // ------------------------------------------------------------------------------------------------
    void PLYImporter::createFromeTriStrip(const ElementInstance *instElement, unsigned int iProperty, EDataType eType) {
        bool flip = false;
        const auto &quak = GetProperty(instElement->alProperties, iProperty).avList;

        std::vector<aiFace> cache;
        int aiTable[2] = { -1, -1 };
        for (auto a = quak.begin(); a != quak.end(); ++a) {
            const int p = PropertyInstance::ConvertTo<int>(*a, eType);

            if (-1 == p) {
                // restart the strip ...
                aiTable[0] = aiTable[1] = -1;
                flip = false;
                continue;
            }
            
            if (-1 == aiTable[0]) {
                aiTable[0] = p;
                continue;
            }
            
            if (-1 == aiTable[1]) {
                aiTable[1] = p;
                continue;
            }
            aiFace face;
            face.mNumIndices = 3;
            face.mIndices = new unsigned int[3];
            face.mIndices[0] = aiTable[0];
            face.mIndices[1] = aiTable[1];
            face.mIndices[2] = p;
            if (flip) {
                std::swap(face.mIndices[0], face.mIndices[1]);
            }
            cache.push_back(face);
            // every second pass swap the indices.
            flip = !flip;

            aiTable[0] = aiTable[1];
            aiTable[1] = p;
        }
        if (mGeneratedMesh->mFaces != nullptr) {
            delete[] mGeneratedMesh->mFaces;
        }
        mGeneratedMesh->mNumFaces = static_cast<unsigned int>(cache.size());
        mGeneratedMesh->mFaces = new aiFace[mGeneratedMesh->mNumFaces];
        std::copy(cache.begin(), cache.end(), mGeneratedMesh->mFaces);
    }

    // ------------------------------------------------------------------------------------------------
    // Extract a material from the PLY DOM
    void PLYImporter::LoadMaterial(std::vector<aiMaterial *> *pvOut, std::string &defaultTexture, const bool pointsOnly) {
        ai_assert(nullptr != pvOut);

        // diffuse[4], specular[4], ambient[4]
        // rgba order
        unsigned int aaiPositions[3][4] = {
            { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
            { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
            { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
        };

        EDataType aaiTypes[3][4] = {
            { EDT_Char, EDT_Char, EDT_Char, EDT_Char },
            { EDT_Char, EDT_Char, EDT_Char, EDT_Char },
            { EDT_Char, EDT_Char, EDT_Char, EDT_Char }
        };
        ElementInstanceList *pcList = nullptr;

        unsigned int iPhong = 0xFFFFFFFF;
        EDataType ePhong = EDT_Char;

        unsigned int iOpacity = 0xFFFFFFFF;
        EDataType eOpacity = EDT_Char;

        // search in the DOM for a vertex entry
        unsigned int _i = 0;
        for (std::vector<Element>::const_iterator i = this->pcDOM->alElements.begin();
                i != this->pcDOM->alElements.end(); ++i, ++_i) {
            if (EEST_Material == i->eSemantic) {
                pcList = &this->pcDOM->alElementData[_i];

                // now check whether which coordinate sets are available
                unsigned int _a = 0;
                for (std::vector<Property>::const_iterator a = i->alProperties.begin(); a != i->alProperties.end(); ++a, ++_a) {
                    if (a->bIsList) {
                        continue;
                    }

                    // pohng specularity      -----------------------------------
                    if (EST_PhongPower == (*a).Semantic) {
                        iPhong = _a;
                        ePhong = (*a).eType;
                    }

                    // general opacity        -----------------------------------
                    if (EST_Opacity == (*a).Semantic) {
                        iOpacity = _a;
                        eOpacity = (*a).eType;
                    }

                    // diffuse color channels -----------------------------------
                    if (EST_DiffuseRed == (*a).Semantic) {
                        aaiPositions[0][0] = _a;
                        aaiTypes[0][0] = (*a).eType;
                    } else if (EST_DiffuseGreen == (*a).Semantic) {
                        aaiPositions[0][1] = _a;
                        aaiTypes[0][1] = (*a).eType;
                    } else if (EST_DiffuseBlue == (*a).Semantic) {
                        aaiPositions[0][2] = _a;
                        aaiTypes[0][2] = (*a).eType;
                    } else if (EST_DiffuseAlpha == (*a).Semantic) {
                        aaiPositions[0][3] = _a;
                        aaiTypes[0][3] = (*a).eType;
                    }
                    // specular color channels -----------------------------------
                    else if (EST_SpecularRed == (*a).Semantic) {
                        aaiPositions[1][0] = _a;
                        aaiTypes[1][0] = (*a).eType;
                    } else if (EST_SpecularGreen == (*a).Semantic) {
                        aaiPositions[1][1] = _a;
                        aaiTypes[1][1] = (*a).eType;
                    } else if (EST_SpecularBlue == (*a).Semantic) {
                        aaiPositions[1][2] = _a;
                        aaiTypes[1][2] = (*a).eType;
                    } else if (EST_SpecularAlpha == (*a).Semantic) {
                        aaiPositions[1][3] = _a;
                        aaiTypes[1][3] = (*a).eType;
                    }
                    // ambient color channels -----------------------------------
                    else if (EST_AmbientRed == (*a).Semantic) {
                        aaiPositions[2][0] = _a;
                        aaiTypes[2][0] = (*a).eType;
                    } else if (EST_AmbientGreen == (*a).Semantic) {
                        aaiPositions[2][1] = _a;
                        aaiTypes[2][1] = (*a).eType;
                    } else if (EST_AmbientBlue == (*a).Semantic) {
                        aaiPositions[2][2] = _a;
                        aaiTypes[2][2] = (*a).eType;
                    } else if (EST_AmbientAlpha == (*a).Semantic) {
                        aaiPositions[2][3] = _a;
                        aaiTypes[2][3] = (*a).eType;
                    }
                }
                break;
            } else if (EEST_TextureFile == i->eSemantic) {
                defaultTexture = i->szName;
            }
        }
        // check whether we have a valid source for the material data
        if (nullptr != pcList) {
            for (std::vector<ElementInstance>::const_iterator i = pcList->alInstances.begin(); i != pcList->alInstances.end(); ++i) {
                aiColor4D clrOut;
                aiMaterial *pcHelper = new aiMaterial();

                // build the diffuse material color
                GetMaterialColor((*i).alProperties, aaiPositions[0], aaiTypes[0], &clrOut);
                pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_DIFFUSE);

                // build the specular material color
                GetMaterialColor((*i).alProperties, aaiPositions[1], aaiTypes[1], &clrOut);
                pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_SPECULAR);

                // build the ambient material color
                GetMaterialColor((*i).alProperties, aaiPositions[2], aaiTypes[2], &clrOut);
                pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_AMBIENT);

                // handle phong power and shading mode
                int iMode = aiShadingMode_Gouraud;
                if (0xFFFFFFFF != iPhong) {
                    ai_real fSpec = PropertyInstance::ConvertTo<ai_real>(GetProperty((*i).alProperties, iPhong).avList.front(), ePhong);

                    // if shininess is 0 (and the pow() calculation would therefore always
                    // become 1, not depending on the angle), use gouraud lighting
                    if (fSpec) {
                        // scale this with 15 ... hopefully this is correct
                        fSpec *= 15;
                        pcHelper->AddProperty<ai_real>(&fSpec, 1, AI_MATKEY_SHININESS);

                        iMode = static_cast<int>(aiShadingMode_Phong);
                    }
                }
                pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

                // handle opacity
                if (0xFFFFFFFF != iOpacity) {
                    ai_real fOpacity = PropertyInstance::ConvertTo<ai_real>(GetProperty((*i).alProperties, iPhong).avList.front(), eOpacity);
                    pcHelper->AddProperty<ai_real>(&fOpacity, 1, AI_MATKEY_OPACITY);
                }

                // The face order is absolutely undefined for PLY, so we have to
                // use two-sided rendering to be sure it's ok.
                const int two_sided = 1;
                pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);

                // default texture
                if (!defaultTexture.empty()) {
                    const aiString name(defaultTexture.c_str());
                    pcHelper->AddProperty(&name, _AI_MATKEY_TEXTURE_BASE, aiTextureType_DIFFUSE, 0);
                }

                if (!pointsOnly) {
                    pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);
                }

                // set to wireframe, so when using this material info we can switch to points rendering
                if (pointsOnly) {
                    constexpr int wireframe = 1;
                    pcHelper->AddProperty(&wireframe, 1, AI_MATKEY_ENABLE_WIREFRAME);
                }

                // add the newly created material instance to the list
                pvOut->push_back(pcHelper);
            }
        } else {
            // generate a default material
            aiMaterial *pcHelper = new aiMaterial();

            // fill in a default material
            int iMode = aiShadingMode_Gouraud;
            pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

            // generate white material most 3D engine just multiply ambient / diffuse color with actual ambient / light color
            aiColor3D clr;
            clr.b = clr.g = clr.r = 1.0f;
            pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_DIFFUSE);
            pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_SPECULAR);

            clr.b = clr.g = clr.r = 1.0f;
            pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_AMBIENT);

            // The face order is absolutely undefined for PLY, so we have to
            // use two-sided rendering to be sure it's ok.
            if (!pointsOnly) {
                const int two_sided = 1;
                pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);
            }

            // default texture
            if (!defaultTexture.empty()) {
                const aiString name(defaultTexture.c_str());
                pcHelper->AddProperty(&name, _AI_MATKEY_TEXTURE_BASE, aiTextureType_DIFFUSE, 0);
            }

            // set to wireframe, so when using this material info we can switch to points rendering
            if (pointsOnly) {
                constexpr int wireframe = 1;
                pcHelper->AddProperty(&wireframe, 1, AI_MATKEY_ENABLE_WIREFRAME);
            }

            pvOut->push_back(pcHelper);
        }
    }

} // namespace Assimp

#endif // !! ASSIMP_BUILD_NO_PLY_IMPORTER