assimp/code/IRRLoader.cpp

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/** @file  IRRLoader.cpp
 *  @brief Implementation of the Irr importer class
 */



#ifndef ASSIMP_BUILD_NO_IRR_IMPORTER

#include "IRRLoader.h"
#include <assimp/ParsingUtils.h>
#include <assimp/fast_atof.h>
#include <assimp/GenericProperty.h>

#include <assimp/SceneCombiner.h>
#include <assimp/StandardShapes.h>
#include "Importer.h"

// We need MathFunctions.h to compute the lcm/gcd of a number
#include <assimp/MathFunctions.h>
#include <memory>
#include <assimp/DefaultLogger.hpp>
#include <assimp/mesh.h>
#include <assimp/material.h>
#include <assimp/scene.h>
#include <assimp/IOSystem.hpp>
#include <assimp/postprocess.h>
#include <assimp/importerdesc.h>

using namespace Assimp;
using namespace irr;
using namespace irr::io;

static const aiImporterDesc desc = {
    "Irrlicht Scene Reader",
    "",
    "",
    "http://irrlicht.sourceforge.net/",
    aiImporterFlags_SupportTextFlavour,
    0,
    0,
    0,
    0,
    "irr xml"
};

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
IRRImporter::IRRImporter()
: fps()
, configSpeedFlag(){
    // empty
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
IRRImporter::~IRRImporter() {
    // empty
}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file.
bool IRRImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const {
    const std::string extension = GetExtension(pFile);
    if ( extension == "irr" ) {
        return true;
    } else if (extension == "xml" || checkSig) {
        /*  If CanRead() is called in order to check whether we
         *  support a specific file extension in general pIOHandler
         *  might be nullptr and it's our duty to return true here.
         */
        if (nullptr == pIOHandler ) {
            return true;
        }
        const char* tokens[] = {"irr_scene"};
        return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
    }

    return false;
}

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

// ------------------------------------------------------------------------------------------------
void IRRImporter::SetupProperties(const Importer* pImp)
{
    // read the output frame rate of all node animation channels
    fps = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_IRR_ANIM_FPS,100);
    if (fps < 10.)  {
        ASSIMP_LOG_ERROR("IRR: Invalid FPS configuration");
        fps = 100;
    }

    // AI_CONFIG_FAVOUR_SPEED
    configSpeedFlag = (0 != pImp->GetPropertyInteger(AI_CONFIG_FAVOUR_SPEED,0));
}

// ------------------------------------------------------------------------------------------------
// Build a mesh tha consists of a single squad (a side of a skybox)
aiMesh* IRRImporter::BuildSingleQuadMesh(const SkyboxVertex& v1,
    const SkyboxVertex& v2,
    const SkyboxVertex& v3,
    const SkyboxVertex& v4)
{
    // allocate and prepare the mesh
    aiMesh* out = new aiMesh();

    out->mPrimitiveTypes = aiPrimitiveType_POLYGON;
    out->mNumFaces = 1;

    // build the face
    out->mFaces    = new aiFace[1];
    aiFace& face   = out->mFaces[0];

    face.mNumIndices = 4;
    face.mIndices    = new unsigned int[4];
    for (unsigned int i = 0; i < 4;++i)
        face.mIndices[i] = i;

    out->mNumVertices = 4;

    // copy vertex positions
    aiVector3D* vec = out->mVertices = new aiVector3D[4];
    *vec++ = v1.position;
    *vec++ = v2.position;
    *vec++ = v3.position;
    *vec   = v4.position;

    // copy vertex normals
    vec = out->mNormals = new aiVector3D[4];
    *vec++ = v1.normal;
    *vec++ = v2.normal;
    *vec++ = v3.normal;
    *vec   = v4.normal;

    // copy texture coordinates
    vec = out->mTextureCoords[0] = new aiVector3D[4];
    *vec++ = v1.uv;
    *vec++ = v2.uv;
    *vec++ = v3.uv;
    *vec   = v4.uv;
    return out;
}

// ------------------------------------------------------------------------------------------------
void IRRImporter::BuildSkybox(std::vector<aiMesh*>& meshes, std::vector<aiMaterial*> materials)
{
    // Update the material of the skybox - replace the name and disable shading for skyboxes.
    for (unsigned int i = 0; i < 6;++i) {
        aiMaterial* out = ( aiMaterial* ) (*(materials.end()-(6-i)));

        aiString s;
        s.length = ::ai_snprintf( s.data, MAXLEN, "SkyboxSide_%u",i );
        out->AddProperty(&s,AI_MATKEY_NAME);

        int shading = aiShadingMode_NoShading;
        out->AddProperty(&shading,1,AI_MATKEY_SHADING_MODEL);
    }

    // Skyboxes are much more difficult. They are represented
    // by six single planes with different textures, so we'll
    // need to build six meshes.

    const ai_real l = 10.0; // the size used by Irrlicht

    // FRONT SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex(-l,-l,-l,  0, 0, 1,   1.0,1.0),
        SkyboxVertex( l,-l,-l,  0, 0, 1,   0.0,1.0),
        SkyboxVertex( l, l,-l,  0, 0, 1,   0.0,0.0),
        SkyboxVertex(-l, l,-l,  0, 0, 1,   1.0,0.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-6u);

    // LEFT SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex( l,-l,-l,  -1, 0, 0,   1.0,1.0),
        SkyboxVertex( l,-l, l,  -1, 0, 0,   0.0,1.0),
        SkyboxVertex( l, l, l,  -1, 0, 0,   0.0,0.0),
        SkyboxVertex( l, l,-l,  -1, 0, 0,   1.0,0.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-5u);

    // BACK SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex( l,-l, l,  0, 0, -1,   1.0,1.0),
        SkyboxVertex(-l,-l, l,  0, 0, -1,   0.0,1.0),
        SkyboxVertex(-l, l, l,  0, 0, -1,   0.0,0.0),
        SkyboxVertex( l, l, l,  0, 0, -1,   1.0,0.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-4u);

    // RIGHT SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex(-l,-l, l,  1, 0, 0,   1.0,1.0),
        SkyboxVertex(-l,-l,-l,  1, 0, 0,   0.0,1.0),
        SkyboxVertex(-l, l,-l,  1, 0, 0,   0.0,0.0),
        SkyboxVertex(-l, l, l,  1, 0, 0,   1.0,0.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-3u);

    // TOP SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex( l, l,-l,  0, -1, 0,   1.0,1.0),
        SkyboxVertex( l, l, l,  0, -1, 0,   0.0,1.0),
        SkyboxVertex(-l, l, l,  0, -1, 0,   0.0,0.0),
        SkyboxVertex(-l, l,-l,  0, -1, 0,   1.0,0.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-2u);

    // BOTTOM SIDE
    meshes.push_back( BuildSingleQuadMesh(
        SkyboxVertex( l,-l, l,  0,  1, 0,   0.0,0.0),
        SkyboxVertex( l,-l,-l,  0,  1, 0,   1.0,0.0),
        SkyboxVertex(-l,-l,-l,  0,  1, 0,   1.0,1.0),
        SkyboxVertex(-l,-l, l,  0,  1, 0,   0.0,1.0)) );
    meshes.back()->mMaterialIndex = static_cast<unsigned int>(materials.size()-1u);
}

// ------------------------------------------------------------------------------------------------
void IRRImporter::CopyMaterial(std::vector<aiMaterial*>& materials,
    std::vector< std::pair<aiMaterial*, unsigned int> >& inmaterials,
    unsigned int& defMatIdx,
    aiMesh* mesh)
{
    if (inmaterials.empty())    {
        // Do we have a default material? If not we need to create one
        if (UINT_MAX == defMatIdx)
        {
            defMatIdx = (unsigned int)materials.size();
            //TODO: add this materials to someone?
            /*aiMaterial* mat = new aiMaterial();

            aiString s;
            s.Set(AI_DEFAULT_MATERIAL_NAME);
            mat->AddProperty(&s,AI_MATKEY_NAME);

            aiColor3D c(0.6f,0.6f,0.6f);
            mat->AddProperty(&c,1,AI_MATKEY_COLOR_DIFFUSE);*/
        }
        mesh->mMaterialIndex = defMatIdx;
        return;
    }
    else if (inmaterials.size() > 1)    {
        ASSIMP_LOG_INFO("IRR: Skipping additional materials");
    }

    mesh->mMaterialIndex = (unsigned int)materials.size();
    materials.push_back(inmaterials[0].first);
}


// ------------------------------------------------------------------------------------------------
inline
int ClampSpline(int idx, int size) {
    return ( idx<0 ? size+idx : ( idx>=size ? idx-size : idx ) );
}

// ------------------------------------------------------------------------------------------------
inline void FindSuitableMultiple(int& angle)
{
    if (angle < 3)angle = 3;
    else if (angle < 10) angle = 10;
    else if (angle < 20) angle = 20;
    else if (angle < 30) angle = 30;
    else
    {
    }
}

// ------------------------------------------------------------------------------------------------
void IRRImporter::ComputeAnimations(Node* root, aiNode* real, std::vector<aiNodeAnim*>& anims)
{
    ai_assert(nullptr != root && nullptr != real);

    // XXX totally WIP - doesn't produce proper results, need to evaluate
    // whether there's any use for Irrlicht's proprietary scene format
    // outside Irrlicht ...

    if (root->animators.empty()) {
        return;
    }
    unsigned int total( 0 );
    for (std::list<Animator>::iterator it = root->animators.begin();it != root->animators.end(); ++it)  {
        if ((*it).type == Animator::UNKNOWN || (*it).type == Animator::OTHER)   {
            ASSIMP_LOG_WARN("IRR: Skipping unknown or unsupported animator");
            continue;
        }
        ++total;
    }
    if (!total) {
        return;
    } else if (1 == total)    {
        ASSIMP_LOG_WARN("IRR: Adding dummy nodes to simulate multiple animators");
    }

    // NOTE: 1 tick == i millisecond

    unsigned int cur = 0;
    for (std::list<Animator>::iterator it = root->animators.begin();
        it != root->animators.end(); ++it)
    {
        if ((*it).type == Animator::UNKNOWN || (*it).type == Animator::OTHER)continue;

        Animator& in = *it ;
        aiNodeAnim* anim = new aiNodeAnim();

        if (cur != total-1) {
            // Build a new name - a prefix instead of a suffix because it is
            // easier to check against
            anim->mNodeName.length = ::ai_snprintf(anim->mNodeName.data, MAXLEN,
                "$INST_DUMMY_%i_%s",total-1,
                (root->name.length() ? root->name.c_str() : ""));

            // we'll also need to insert a dummy in the node hierarchy.
            aiNode* dummy = new aiNode();

            for (unsigned int i = 0; i < real->mParent->mNumChildren;++i)
                if (real->mParent->mChildren[i] == real)
                    real->mParent->mChildren[i] = dummy;

            dummy->mParent = real->mParent;
            dummy->mName = anim->mNodeName;

            dummy->mNumChildren = 1;
            dummy->mChildren = new aiNode*[dummy->mNumChildren];
            dummy->mChildren[0] = real;

            // the transformation matrix of the dummy node is the identity

            real->mParent = dummy;
        }
        else anim->mNodeName.Set(root->name);
        ++cur;

        switch (in.type)    {
        case Animator::ROTATION:
            {
                // -----------------------------------------------------
                // find out how long a full rotation will take
                // This is the least common multiple of 360.f and all
                // three euler angles. Although we'll surely find a
                // possible multiple (haha) it could be somewhat large
                // for our purposes. So we need to modify the angles
                // here in order to get good results.
                // -----------------------------------------------------
                int angles[3];
                angles[0] = (int)(in.direction.x*100);
                angles[1] = (int)(in.direction.y*100);
                angles[2] = (int)(in.direction.z*100);

                angles[0] %= 360;
                angles[1] %= 360;
                angles[2] %= 360;

                if ( (angles[0]*angles[1]) != 0 && (angles[1]*angles[2]) != 0 )
                {
                    FindSuitableMultiple(angles[0]);
                    FindSuitableMultiple(angles[1]);
                    FindSuitableMultiple(angles[2]);
                }

                int lcm = 360;

                if (angles[0])
                    lcm  = Math::lcm(lcm,angles[0]);

                if (angles[1])
                    lcm  = Math::lcm(lcm,angles[1]);

                if (angles[2])
                    lcm  = Math::lcm(lcm,angles[2]);

                if (360 == lcm)
                    break;

#if 0
                // This can be a division through zero, but we don't care
                float f1 = (float)lcm / angles[0];
                float f2 = (float)lcm / angles[1];
                float f3 = (float)lcm / angles[2];
#endif

                // find out how many time units we'll need for the finest
                // track (in seconds) - this defines the number of output
                // keys (fps * seconds)
                float max  = 0.f;
                if (angles[0])
                    max = (float)lcm / angles[0];
                if (angles[1])
                    max = std::max(max, (float)lcm / angles[1]);
                if (angles[2])
                    max = std::max(max, (float)lcm / angles[2]);

                anim->mNumRotationKeys = (unsigned int)(max*fps);
                anim->mRotationKeys = new aiQuatKey[anim->mNumRotationKeys];

                // begin with a zero angle
                aiVector3D angle;
                for (unsigned int i = 0; i < anim->mNumRotationKeys;++i)
                {
                    // build the quaternion for the given euler angles
                    aiQuatKey& q = anim->mRotationKeys[i];

                    q.mValue = aiQuaternion(angle.x, angle.y, angle.z);
                    q.mTime = (double)i;

                    // increase the angle
                    angle += in.direction;
                }

                // This animation is repeated and repeated ...
                anim->mPostState = anim->mPreState = aiAnimBehaviour_REPEAT;
            }
            break;

        case Animator::FLY_CIRCLE:
            {
                // -----------------------------------------------------
                // Find out how much time we'll need to perform a
                // full circle.
                // -----------------------------------------------------
                const double seconds = (1. / in.speed) / 1000.;
                const double tdelta = 1000. / fps;

                anim->mNumPositionKeys = (unsigned int) (fps * seconds);
                anim->mPositionKeys = new aiVectorKey[anim->mNumPositionKeys];

                // from Irrlicht, what else should we do than copying it?
                aiVector3D vecU,vecV;
                if (in.direction.y) {
                    vecV = aiVector3D(50,0,0) ^ in.direction;
                }
                else vecV = aiVector3D(0,50,00) ^ in.direction;
                vecV.Normalize();
                vecU = (vecV ^ in.direction).Normalize();

                // build the output keys
                for (unsigned int i = 0; i < anim->mNumPositionKeys;++i)    {
                    aiVectorKey& key = anim->mPositionKeys[i];
                    key.mTime = i * tdelta;

                    const ai_real t = (ai_real) ( in.speed * key.mTime );
                    key.mValue = in.circleCenter  + in.circleRadius * ((vecU * std::cos(t)) + (vecV * std::sin(t)));
                }

                // This animation is repeated and repeated ...
                anim->mPostState = anim->mPreState = aiAnimBehaviour_REPEAT;
            }
            break;

        case Animator::FLY_STRAIGHT:
            {
                anim->mPostState = anim->mPreState = (in.loop ? aiAnimBehaviour_REPEAT : aiAnimBehaviour_CONSTANT);
                const double seconds = in.timeForWay / 1000.;
                const double tdelta = 1000. / fps;

                anim->mNumPositionKeys = (unsigned int) (fps * seconds);
                anim->mPositionKeys = new aiVectorKey[anim->mNumPositionKeys];

                aiVector3D diff = in.direction - in.circleCenter;
                const ai_real lengthOfWay = diff.Length();
                diff.Normalize();

                const double timeFactor = lengthOfWay / in.timeForWay;

                // build the output keys
                for (unsigned int i = 0; i < anim->mNumPositionKeys;++i)    {
                    aiVectorKey& key = anim->mPositionKeys[i];
                    key.mTime = i * tdelta;
                    key.mValue = in.circleCenter + diff * ai_real(timeFactor * key.mTime);
                }
            }
            break;

        case Animator::FOLLOW_SPLINE:
            {
                // repeat outside the defined time range
                anim->mPostState = anim->mPreState = aiAnimBehaviour_REPEAT;
                const int size = (int)in.splineKeys.size();
                if (!size)  {
                    // We have no point in the spline. That's bad. Really bad.
                    ASSIMP_LOG_WARN("IRR: Spline animators with no points defined");

                    delete anim;
                    anim = nullptr;
                    break;
                }
                else if (size == 1) {
                    // We have just one point in the spline so we don't need the full calculation
                    anim->mNumPositionKeys = 1;
                    anim->mPositionKeys = new aiVectorKey[anim->mNumPositionKeys];

                    anim->mPositionKeys[0].mValue = in.splineKeys[0].mValue;
                    anim->mPositionKeys[0].mTime  = 0.f;
                    break;
                }

                unsigned int ticksPerFull = 15;
                anim->mNumPositionKeys = (unsigned int) ( ticksPerFull * fps );
                anim->mPositionKeys = new aiVectorKey[anim->mNumPositionKeys];

                for (unsigned int i = 0; i < anim->mNumPositionKeys;++i)
                {
                    aiVectorKey& key = anim->mPositionKeys[i];

                    const ai_real dt = (i * in.speed * ai_real( 0.001 ) );
                    const ai_real u = dt - std::floor(dt);
                    const int idx = (int)std::floor(dt) % size;

                    // get the 4 current points to evaluate the spline
                    const aiVector3D& p0 = in.splineKeys[ ClampSpline( idx - 1, size ) ].mValue;
                    const aiVector3D& p1 = in.splineKeys[ ClampSpline( idx + 0, size ) ].mValue;
                    const aiVector3D& p2 = in.splineKeys[ ClampSpline( idx + 1, size ) ].mValue;
                    const aiVector3D& p3 = in.splineKeys[ ClampSpline( idx + 2, size ) ].mValue;

                    // compute polynomials
                    const ai_real u2 = u*u;
                    const ai_real u3 = u2*2;

                    const ai_real h1 = ai_real( 2.0 ) * u3 - ai_real( 3.0 ) * u2 + ai_real( 1.0 );
                    const ai_real h2 = ai_real( -2.0 ) * u3 + ai_real( 3.0 ) * u3;
                    const ai_real h3 = u3 - ai_real( 2.0 ) * u3;
                    const ai_real h4 = u3 - u2;

                    // compute the spline tangents
                    const aiVector3D t1 = ( p2 - p0 ) * in.tightness;
                    aiVector3D t2 = ( p3 - p1 ) * in.tightness;

                    // and use them to get the interpolated point
                    t2 = (h1 * p1 + p2 * h2 + t1 * h3 + h4 * t2);

                    // build a simple translation matrix from it
                    key.mValue = t2;
                    key.mTime  = (double) i;
                }
            }
            break;
        default:
            // UNKNOWN , OTHER
            break;
        };
        if (anim)   {
            anims.push_back(anim);
            ++total;
        }
    }
}

// ------------------------------------------------------------------------------------------------
// This function is maybe more generic than we'd need it here
void SetupMapping (aiMaterial* mat, aiTextureMapping mode, const aiVector3D& axis = aiVector3D(0.f,0.f,-1.f))
{
    // Check whether there are texture properties defined - setup
    // the desired texture mapping mode for all of them and ignore
    // all UV settings we might encounter. WE HAVE NO UVS!

    std::vector<aiMaterialProperty*> p;
    p.reserve(mat->mNumProperties+1);

    for (unsigned int i = 0; i < mat->mNumProperties;++i)
    {
        aiMaterialProperty* prop = mat->mProperties[i];
        if (!::strcmp( prop->mKey.data, "$tex.file"))   {
            // Setup the mapping key
            aiMaterialProperty* m = new aiMaterialProperty();
            m->mKey.Set("$tex.mapping");
            m->mIndex    = prop->mIndex;
            m->mSemantic = prop->mSemantic;
            m->mType     = aiPTI_Integer;

            m->mDataLength = 4;
            m->mData = new char[4];
            *((int*)m->mData) = mode;

            p.push_back(prop);
            p.push_back(m);

            // Setup the mapping axis
            if (mode == aiTextureMapping_CYLINDER || mode == aiTextureMapping_PLANE || mode == aiTextureMapping_SPHERE) {
                m = new aiMaterialProperty();
                m->mKey.Set("$tex.mapaxis");
                m->mIndex    = prop->mIndex;
                m->mSemantic = prop->mSemantic;
                m->mType     = aiPTI_Float;

                m->mDataLength = 12;
                m->mData = new char[12];
                *((aiVector3D*)m->mData) = axis;
                p.push_back(m);
            }
        }
        else if (! ::strcmp( prop->mKey.data, "$tex.uvwsrc"))   {
            delete mat->mProperties[i];
        }
        else p.push_back(prop);
    }

    if (p.empty())return;

    // rebuild the output array
    if (p.size() > mat->mNumAllocated)  {
        delete[] mat->mProperties;
        mat->mProperties = new aiMaterialProperty*[p.size()*2];

        mat->mNumAllocated = static_cast<unsigned int>(p.size()*2);
    }
    mat->mNumProperties = (unsigned int)p.size();
    ::memcpy(mat->mProperties,&p[0],sizeof(void*)*mat->mNumProperties);
}

// ------------------------------------------------------------------------------------------------
void IRRImporter::GenerateGraph(Node* root,aiNode* rootOut ,aiScene* scene,
    BatchLoader& batch,
    std::vector<aiMesh*>&        meshes,
    std::vector<aiNodeAnim*>&    anims,
    std::vector<AttachmentInfo>& attach,
    std::vector<aiMaterial*>&    materials,
    unsigned int&                defMatIdx)
{
    unsigned int oldMeshSize = (unsigned int)meshes.size();
    //unsigned int meshTrafoAssign = 0;

    // Now determine the type of the node
    switch (root->type)
    {
    case Node::ANIMMESH:
    case Node::MESH:
        {
            if (!root->meshPath.length())
                break;

            // Get the loaded mesh from the scene and add it to
            // the list of all scenes to be attached to the
            // graph we're currently building
            aiScene* scene = batch.GetImport(root->id);
            if (!scene) {
                ASSIMP_LOG_ERROR("IRR: Unable to load external file: " + root->meshPath);
                break;
            }
            attach.push_back(AttachmentInfo(scene,rootOut));

            // Now combine the material we've loaded for this mesh
            // with the real materials we got from the file. As we
            // don't execute any pp-steps on the file, the numbers
            // should be equal. If they are not, we can impossibly
            // do this  ...
            if (root->materials.size() != (unsigned int)scene->mNumMaterials)   {
                ASSIMP_LOG_WARN("IRR: Failed to match imported materials "
                    "with the materials found in the IRR scene file");

                break;
            }
            for (unsigned int i = 0; i < scene->mNumMaterials;++i)  {
                // Delete the old material, we don't need it anymore
                delete scene->mMaterials[i];

                std::pair<aiMaterial*, unsigned int>& src = root->materials[i];
                scene->mMaterials[i] = src.first;
            }

            // NOTE: Each mesh should have exactly one material assigned,
            // but we do it in a separate loop if this behaviour changes
            // in future.
            for (unsigned int i = 0; i < scene->mNumMeshes;++i) {
                // Process material flags
                aiMesh* mesh = scene->mMeshes[i];


                // If "trans_vertex_alpha" mode is enabled, search all vertex colors
                // and check whether they have a common alpha value. This is quite
                // often the case so we can simply extract it to a shared oacity
                // value.
                std::pair<aiMaterial*, unsigned int>& src = root->materials[mesh->mMaterialIndex];
                aiMaterial* mat = (aiMaterial*)src.first;

                if (mesh->HasVertexColors(0) && src.second & AI_IRRMESH_MAT_trans_vertex_alpha)
                {
                    bool bdo = true;
                    for (unsigned int a = 1; a < mesh->mNumVertices;++a)    {

                        if (mesh->mColors[0][a].a != mesh->mColors[0][a-1].a)   {
                            bdo = false;
                            break;
                        }
                    }
                    if (bdo)    {
                        ASSIMP_LOG_INFO("IRR: Replacing mesh vertex alpha with common opacity");

                        for (unsigned int a = 0; a < mesh->mNumVertices;++a)
                            mesh->mColors[0][a].a = 1.f;

                        mat->AddProperty(& mesh->mColors[0][0].a, 1, AI_MATKEY_OPACITY);
                    }
                }

                // If we have a second texture coordinate set and a second texture
                // (either lightmap, normalmap, 2layered material) we need to
                // setup the correct UV index for it. The texture can either
                // be diffuse (lightmap & 2layer) or a normal map (normal & parallax)
                if (mesh->HasTextureCoords(1))  {

                    int idx = 1;
                    if (src.second & (AI_IRRMESH_MAT_solid_2layer | AI_IRRMESH_MAT_lightmap))   {
                        mat->AddProperty(&idx,1,AI_MATKEY_UVWSRC_DIFFUSE(0));
                    }
                    else if (src.second & AI_IRRMESH_MAT_normalmap_solid)   {
                        mat->AddProperty(&idx,1,AI_MATKEY_UVWSRC_NORMALS(0));
                    }
                }
            }
        }
        break;

    case Node::LIGHT:
    case Node::CAMERA:

        // We're already finished with lights and cameras
        break;


    case Node::SPHERE:
        {
            // Generate the sphere model. Our input parameter to
            // the sphere generation algorithm is the number of
            // subdivisions of each triangle - but here we have
            // the number of poylgons on a specific axis. Just
            // use some hardcoded limits to approximate this ...
            unsigned int mul = root->spherePolyCountX*root->spherePolyCountY;
            if      (mul < 100)mul = 2;
            else if (mul < 300)mul = 3;
            else               mul = 4;

            meshes.push_back(StandardShapes::MakeMesh(mul,
                &StandardShapes::MakeSphere));

            // Adjust scaling
            root->scaling *= root->sphereRadius/2;

            // Copy one output material
            CopyMaterial(materials, root->materials, defMatIdx, meshes.back());

            // Now adjust this output material - if there is a first texture
            // set, setup spherical UV mapping around the Y axis.
            SetupMapping ( (aiMaterial*) materials.back(), aiTextureMapping_SPHERE);
        }
        break;

    case Node::CUBE:
        {
            // Generate an unit cube first
            meshes.push_back(StandardShapes::MakeMesh(
                &StandardShapes::MakeHexahedron));

            // Adjust scaling
            root->scaling *= root->sphereRadius;

            // Copy one output material
            CopyMaterial(materials, root->materials, defMatIdx, meshes.back());

            // Now adjust this output material - if there is a first texture
            // set, setup cubic UV mapping
            SetupMapping ( (aiMaterial*) materials.back(), aiTextureMapping_BOX );
        }
        break;


    case Node::SKYBOX:
        {
            // A skybox is defined by six materials
            if (root->materials.size() < 6) {
                ASSIMP_LOG_ERROR("IRR: There should be six materials for a skybox");
                break;
            }

            // copy those materials and generate 6 meshes for our new skybox
            materials.reserve(materials.size() + 6);
            for (unsigned int i = 0; i < 6;++i)
                materials.insert(materials.end(),root->materials[i].first);

            BuildSkybox(meshes,materials);

            // *************************************************************
            // Skyboxes will require a different code path for rendering,
            // so there must be a way for the user to add special support
            // for IRR skyboxes. We add a 'IRR.SkyBox_' prefix to the node.
            // *************************************************************
            root->name = "IRR.SkyBox_" + root->name;
            ASSIMP_LOG_INFO("IRR: Loading skybox, this will "
                "require special handling to be displayed correctly");
        }
        break;

    case Node::TERRAIN:
        {
            // to support terrains, we'd need to have a texture decoder
            ASSIMP_LOG_ERROR("IRR: Unsupported node - TERRAIN");
        }
        break;
    default:
        // DUMMY
        break;
    };

    // Check whether we added a mesh (or more than one ...). In this case
    // we'll also need to attach it to the node
    if (oldMeshSize != (unsigned int) meshes.size())    {

        rootOut->mNumMeshes = (unsigned int)meshes.size() - oldMeshSize;
        rootOut->mMeshes    = new unsigned int[rootOut->mNumMeshes];

        for (unsigned int a = 0; a  < rootOut->mNumMeshes;++a)  {
            rootOut->mMeshes[a] = oldMeshSize+a;
        }
    }

    // Setup the name of this node
    rootOut->mName.Set(root->name);

    // Now compute the final local transformation matrix of the
    // node from the given translation, rotation and scaling values.
    // (the rotation is given in Euler angles, XYZ order)
    //std::swap((float&)root->rotation.z,(float&)root->rotation.y);
    rootOut->mTransformation.FromEulerAnglesXYZ(AI_DEG_TO_RAD(root->rotation) );

    // apply scaling
    aiMatrix4x4& mat = rootOut->mTransformation;
    mat.a1 *= root->scaling.x;
    mat.b1 *= root->scaling.x;
    mat.c1 *= root->scaling.x;
    mat.a2 *= root->scaling.y;
    mat.b2 *= root->scaling.y;
    mat.c2 *= root->scaling.y;
    mat.a3 *= root->scaling.z;
    mat.b3 *= root->scaling.z;
    mat.c3 *= root->scaling.z;

    // apply translation
    mat.a4 += root->position.x;
    mat.b4 += root->position.y;
    mat.c4 += root->position.z;

    // now compute animations for the node
    ComputeAnimations(root,rootOut, anims);

    // Add all children recursively. First allocate enough storage
    // for them, then call us again
    rootOut->mNumChildren = (unsigned int)root->children.size();
    if (rootOut->mNumChildren)  {

        rootOut->mChildren = new aiNode*[rootOut->mNumChildren];
        for (unsigned int i = 0; i < rootOut->mNumChildren;++i) {

            aiNode* node = rootOut->mChildren[i] =  new aiNode();
            node->mParent = rootOut;
            GenerateGraph(root->children[i],node,scene,batch,meshes,
                anims,attach,materials,defMatIdx);
        }
    }
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure.
void IRRImporter::InternReadFile( const std::string& pFile,
    aiScene* pScene, IOSystem* pIOHandler)
{
    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile));

    // Check whether we can read from the file
    if (file.get() == nullptr) {
        throw DeadlyImportError("Failed to open IRR file " + pFile + "");
    }

    // Construct the irrXML parser
    CIrrXML_IOStreamReader st(file.get());
    reader = createIrrXMLReader((IFileReadCallBack*) &st);

    // The root node of the scene
    Node* root = new Node(Node::DUMMY);
    root->parent = nullptr;
    root->name = "<IRRSceneRoot>";

    // Current node parent
    Node* curParent = root;

    // Scenegraph node we're currently working on
    Node* curNode = nullptr;

    // List of output cameras
    std::vector<aiCamera*> cameras;

    // List of output lights
    std::vector<aiLight*> lights;

    // Batch loader used to load external models
    BatchLoader batch(pIOHandler);
//  batch.SetBasePath(pFile);

    cameras.reserve(5);
    lights.reserve(5);

    bool inMaterials = false, inAnimator = false;
    unsigned int guessedAnimCnt = 0, guessedMeshCnt = 0, guessedMatCnt = 0;

    // Parse the XML file
    while (reader->read())  {
        switch (reader->getNodeType())  {
        case EXN_ELEMENT:

            if (!ASSIMP_stricmp(reader->getNodeName(),"node"))  {
                // ***********************************************************************
                /*  What we're going to do with the node depends
                 *  on its type:
                 *
                 *  "mesh" - Load a mesh from an external file
                 *  "cube" - Generate a cube
                 *  "skybox" - Generate a skybox
                 *  "light" - A light source
                 *  "sphere" - Generate a sphere mesh
                 *  "animatedMesh" - Load an animated mesh from an external file
                 *    and join its animation channels with ours.
                 *  "empty" - A dummy node
                 *  "camera" - A camera
                 *  "terrain" - a terrain node (data comes from a heightmap)
                 *  "billboard", ""
                 *
                 *  Each of these nodes can be animated and all can have multiple
                 *  materials assigned (except lights, cameras and dummies, of course).
                 */
                // ***********************************************************************
                const char* sz = reader->getAttributeValueSafe("type");
                Node* nd;
                if (!ASSIMP_stricmp(sz,"mesh") || !ASSIMP_stricmp(sz,"octTree"))    {
                    // OctTree's and meshes are treated equally
                    nd = new Node(Node::MESH);
                }
                else if (!ASSIMP_stricmp(sz,"cube"))    {
                    nd = new Node(Node::CUBE);
                    ++guessedMeshCnt;
                    // meshes.push_back(StandardShapes::MakeMesh(&StandardShapes::MakeHexahedron));
                }
                else if (!ASSIMP_stricmp(sz,"skybox"))  {
                    nd = new Node(Node::SKYBOX);
                    guessedMeshCnt += 6;
                }
                else if (!ASSIMP_stricmp(sz,"camera"))  {
                    nd = new Node(Node::CAMERA);

                    // Setup a temporary name for the camera
                    aiCamera* cam = new aiCamera();
                    cam->mName.Set( nd->name );
                    cameras.push_back(cam);
                }
                else if (!ASSIMP_stricmp(sz,"light"))   {
                    nd = new Node(Node::LIGHT);

                    // Setup a temporary name for the light
                    aiLight* cam = new aiLight();
                    cam->mName.Set( nd->name );
                    lights.push_back(cam);
                }
                else if (!ASSIMP_stricmp(sz,"sphere"))  {
                    nd = new Node(Node::SPHERE);
                    ++guessedMeshCnt;
                }
                else if (!ASSIMP_stricmp(sz,"animatedMesh"))    {
                    nd = new Node(Node::ANIMMESH);
                }
                else if (!ASSIMP_stricmp(sz,"empty"))   {
                    nd = new Node(Node::DUMMY);
                }
                else if (!ASSIMP_stricmp(sz,"terrain")) {
                    nd = new Node(Node::TERRAIN);
                }
                else if (!ASSIMP_stricmp(sz,"billBoard"))   {
                    // We don't support billboards, so ignore them
                    ASSIMP_LOG_ERROR("IRR: Billboards are not supported by Assimp");
                    nd = new Node(Node::DUMMY);
                }
                else    {
                    ASSIMP_LOG_WARN("IRR: Found unknown node: " + std::string(sz));

                    /*  We skip the contents of nodes we don't know.
                     *  We parse the transformation and all animators
                     *  and skip the rest.
                     */
                    nd = new Node(Node::DUMMY);
                }

                /* Attach the newly created node to the scenegraph
                 */
                curNode = nd;
                nd->parent = curParent;
                curParent->children.push_back(nd);
            }
            else if (!ASSIMP_stricmp(reader->getNodeName(),"materials"))    {
                inMaterials = true;
            }
            else if (!ASSIMP_stricmp(reader->getNodeName(),"animators"))    {
                inAnimator = true;
            }
            else if (!ASSIMP_stricmp(reader->getNodeName(),"attributes"))   {
                /*  We should have a valid node here
                 *  FIX: no ... the scene root node is also contained in an attributes block
                 */
                if (!curNode)   {
#if 0
                    ASSIMP_LOG_ERROR("IRR: Encountered <attributes> element, but "
                        "there is no node active");
#endif
                    continue;
                }

                Animator* curAnim = nullptr;

                // Materials can occur for nearly any type of node
                if (inMaterials && curNode->type != Node::DUMMY)    {
                    /*  This is a material description - parse it!
                     */
                    curNode->materials.push_back(std::pair< aiMaterial*, unsigned int > () );
                    std::pair< aiMaterial*, unsigned int >& p = curNode->materials.back();

                    p.first = ParseMaterial(p.second);

                    ++guessedMatCnt;
                    continue;
                }
                else if (inAnimator)    {
                    /*  This is an animation path - add a new animator
                     *  to the list.
                     */
                    curNode->animators.push_back(Animator());
                    curAnim = & curNode->animators.back();

                    ++guessedAnimCnt;
                }

                /*  Parse all elements in the attributes block
                 *  and process them.
                 */
                while (reader->read())  {
                    if (reader->getNodeType() == EXN_ELEMENT)   {
                        if (!ASSIMP_stricmp(reader->getNodeName(),"vector3d"))  {
                            VectorProperty prop;
                            ReadVectorProperty(prop);

                            if (inAnimator) {
                                if (curAnim->type == Animator::ROTATION && prop.name == "Rotation") {
                                    // We store the rotation euler angles in 'direction'
                                    curAnim->direction = prop.value;
                                }
                                else if (curAnim->type == Animator::FOLLOW_SPLINE)  {
                                    // Check whether the vector follows the PointN naming scheme,
                                    // here N is the ONE-based index of the point
                                    if (prop.name.length() >= 6 && prop.name.substr(0,5) == "Point")    {
                                        // Add a new key to the list
                                        curAnim->splineKeys.push_back(aiVectorKey());
                                        aiVectorKey& key = curAnim->splineKeys.back();

                                        // and parse its properties
                                        key.mValue = prop.value;
                                        key.mTime  = strtoul10(&prop.name[5]);
                                    }
                                }
                                else if (curAnim->type == Animator::FLY_CIRCLE) {
                                    if (prop.name == "Center")  {
                                        curAnim->circleCenter = prop.value;
                                    }
                                    else if (prop.name == "Direction")  {
                                        curAnim->direction = prop.value;

                                        // From Irrlicht's source - a workaround for backward compatibility with Irrlicht 1.1
                                        if (curAnim->direction == aiVector3D()) {
                                            curAnim->direction = aiVector3D(0.f,1.f,0.f);
                                        }
                                        else curAnim->direction.Normalize();
                                    }
                                }
                                else if (curAnim->type == Animator::FLY_STRAIGHT)   {
                                    if (prop.name == "Start")   {
                                        // We reuse the field here
                                        curAnim->circleCenter = prop.value;
                                    }
                                    else if (prop.name == "End")    {
                                        // We reuse the field here
                                        curAnim->direction = prop.value;
                                    }
                                }
                            }
                            else    {
                                if (prop.name == "Position")    {
                                    curNode->position = prop.value;
                                }
                                else if (prop.name == "Rotation")   {
                                    curNode->rotation = prop.value;
                                }
                                else if (prop.name == "Scale")  {
                                    curNode->scaling = prop.value;
                                }
                                else if (Node::CAMERA == curNode->type)
                                {
                                    aiCamera* cam = cameras.back();
                                    if (prop.name == "Target")  {
                                        cam->mLookAt = prop.value;
                                    }
                                    else if (prop.name == "UpVector")   {
                                        cam->mUp = prop.value;
                                    }
                                }
                            }
                        }
                        else if (!ASSIMP_stricmp(reader->getNodeName(),"bool")) {
                            BoolProperty prop;
                            ReadBoolProperty(prop);

                            if (inAnimator && curAnim->type == Animator::FLY_CIRCLE && prop.name == "Loop") {
                                curAnim->loop = prop.value;
                            }
                        }
                        else if (!ASSIMP_stricmp(reader->getNodeName(),"float"))    {
                            FloatProperty prop;
                            ReadFloatProperty(prop);

                            if (inAnimator) {
                                // The speed property exists for several animators
                                if (prop.name == "Speed")   {
                                    curAnim->speed = prop.value;
                                }
                                else if (curAnim->type == Animator::FLY_CIRCLE && prop.name == "Radius")    {
                                    curAnim->circleRadius = prop.value;
                                }
                                else if (curAnim->type == Animator::FOLLOW_SPLINE && prop.name == "Tightness")  {
                                    curAnim->tightness = prop.value;
                                }
                            }
                            else    {
                                if (prop.name == "FramesPerSecond" && Node::ANIMMESH == curNode->type)  {
                                    curNode->framesPerSecond = prop.value;
                                }
                                else if (Node::CAMERA == curNode->type) {
                                    /*  This is the vertical, not the horizontal FOV.
                                    *  We need to compute the right FOV from the
                                    *  screen aspect which we don't know yet.
                                    */
                                    if (prop.name == "Fovy")    {
                                        cameras.back()->mHorizontalFOV  = prop.value;
                                    }
                                    else if (prop.name == "Aspect") {
                                        cameras.back()->mAspect = prop.value;
                                    }
                                    else if (prop.name == "ZNear")  {
                                        cameras.back()->mClipPlaneNear = prop.value;
                                    }
                                    else if (prop.name == "ZFar")   {
                                        cameras.back()->mClipPlaneFar = prop.value;
                                    }
                                }
                                else if (Node::LIGHT == curNode->type)  {
                                    /*  Additional light information
                                     */
                                    if (prop.name == "Attenuation") {
                                        lights.back()->mAttenuationLinear  = prop.value;
                                    }
                                    else if (prop.name == "OuterCone")  {
                                        lights.back()->mAngleOuterCone =  AI_DEG_TO_RAD( prop.value );
                                    }
                                    else if (prop.name == "InnerCone")  {
                                        lights.back()->mAngleInnerCone =  AI_DEG_TO_RAD( prop.value );
                                    }
                                }
                                // radius of the sphere to be generated -
                                // or alternatively, size of the cube
                                else if ((Node::SPHERE == curNode->type && prop.name == "Radius")
                                    || (Node::CUBE == curNode->type   && prop.name == "Size" )) {

                                        curNode->sphereRadius = prop.value;
                                }
                            }
                        }
                        else if (!ASSIMP_stricmp(reader->getNodeName(),"int"))  {
                            IntProperty prop;
                            ReadIntProperty(prop);

                            if (inAnimator) {
                                if (curAnim->type == Animator::FLY_STRAIGHT && prop.name == "TimeForWay")   {
                                    curAnim->timeForWay = prop.value;
                                }
                            }
                            else    {
                                // sphere polgon numbers in each direction
                                if (Node::SPHERE == curNode->type)  {

                                    if (prop.name == "PolyCountX")  {
                                        curNode->spherePolyCountX = prop.value;
                                    }
                                    else if (prop.name == "PolyCountY") {
                                        curNode->spherePolyCountY = prop.value;
                                    }
                                }
                            }
                        }
                        else if (!ASSIMP_stricmp(reader->getNodeName(),"string") ||!ASSIMP_stricmp(reader->getNodeName(),"enum"))   {
                            StringProperty prop;
                            ReadStringProperty(prop);
                            if (prop.value.length())    {
                                if (prop.name == "Name")    {
                                    curNode->name = prop.value;

                                    /*  If we're either a camera or a light source
                                     *  we need to update the name in the aiLight/
                                     *  aiCamera structure, too.
                                     */
                                    if (Node::CAMERA == curNode->type)  {
                                        cameras.back()->mName.Set(prop.value);
                                    }
                                    else if (Node::LIGHT == curNode->type)  {
                                        lights.back()->mName.Set(prop.value);
                                    }
                                }
                                else if (Node::LIGHT == curNode->type && "LightType" == prop.name)
                                {
                                    if (prop.value == "Spot")
                                        lights.back()->mType = aiLightSource_SPOT;
                                    else if (prop.value == "Point")
                                        lights.back()->mType = aiLightSource_POINT;
                                    else if (prop.value == "Directional")
                                        lights.back()->mType = aiLightSource_DIRECTIONAL;
                                    else
                                    {
                                        // We won't pass the validation with aiLightSourceType_UNDEFINED,
                                        // so we remove the light and replace it with a silly dummy node
                                        delete lights.back();
                                        lights.pop_back();
                                        curNode->type = Node::DUMMY;

                                        ASSIMP_LOG_ERROR("Ignoring light of unknown type: " + prop.value);
                                    }
                                }
                                else if ((prop.name == "Mesh" && Node::MESH == curNode->type) ||
                                    Node::ANIMMESH == curNode->type)
                                {
                                    /*  This is the file name of the mesh - either
                                     *  animated or not. We need to make sure we setup
                                     *  the correct post-processing settings here.
                                     */
                                    unsigned int pp = 0;
                                    BatchLoader::PropertyMap map;

                                    /* If the mesh is a static one remove all animations from the impor data
                                     */
                                    if (Node::ANIMMESH != curNode->type)    {
                                        pp |= aiProcess_RemoveComponent;
                                        SetGenericProperty<int>(map.ints,AI_CONFIG_PP_RVC_FLAGS,
                                            aiComponent_ANIMATIONS | aiComponent_BONEWEIGHTS);
                                    }

                                    /*  TODO: maybe implement the protection against recursive
                                    *  loading calls directly in BatchLoader? The current
                                    *  implementation is not absolutely safe. A LWS and an IRR
                                    *  file referencing each other *could* cause the system to
                                    *  recurse forever.
                                    */

                                    const std::string extension = GetExtension(prop.value);
                                    if ("irr" == extension) {
                                        ASSIMP_LOG_ERROR("IRR: Can't load another IRR file recursively");
                                    }
                                    else
                                    {
                                        curNode->id = batch.AddLoadRequest(prop.value,pp,&map);
                                        curNode->meshPath = prop.value;
                                    }
                                }
                                else if (inAnimator && prop.name == "Type")
                                {
                                    // type of the animator
                                    if (prop.value == "rotation")   {
                                        curAnim->type = Animator::ROTATION;
                                    }
                                    else if (prop.value == "flyCircle") {
                                        curAnim->type = Animator::FLY_CIRCLE;
                                    }
                                    else if (prop.value == "flyStraight")   {
                                        curAnim->type = Animator::FLY_CIRCLE;
                                    }
                                    else if (prop.value == "followSpline")  {
                                        curAnim->type = Animator::FOLLOW_SPLINE;
                                    }
                                    else    {
                                        ASSIMP_LOG_WARN("IRR: Ignoring unknown animator: "
                                            + prop.value);

                                        curAnim->type = Animator::UNKNOWN;
                                    }
                                }
                            }
                        }
                    }
                    else if (reader->getNodeType() == EXN_ELEMENT_END && !ASSIMP_stricmp(reader->getNodeName(),"attributes"))   {
                        break;
                    }
                }
            }
            break;

        case EXN_ELEMENT_END:

            // If we reached the end of a node, we need to continue processing its parent
            if (!ASSIMP_stricmp(reader->getNodeName(),"node"))  {
                if (!curNode)   {
                    // currently is no node set. We need to go
                    // back in the node hierarchy
                    if (!curParent) {
                        curParent = root;
                        ASSIMP_LOG_ERROR("IRR: Too many closing <node> elements");
                    }
                    else curParent = curParent->parent;
                }
                else curNode = nullptr;
            }
            // clear all flags
            else if (!ASSIMP_stricmp(reader->getNodeName(),"materials"))    {
                inMaterials = false;
            }
            else if (!ASSIMP_stricmp(reader->getNodeName(),"animators"))    {
                inAnimator = false;
            }
            break;

        default:
            // GCC complains that not all enumeration values are handled
            break;
        }
    }

    //  Now iterate through all cameras and compute their final (horizontal) FOV
    for (aiCamera *cam : cameras) {
        // screen aspect could be missing
        if (cam->mAspect)   {
            cam->mHorizontalFOV *= cam->mAspect;
        } else {
            ASSIMP_LOG_WARN("IRR: Camera aspect is not given, can't compute horizontal FOV");
        }
    }

    batch.LoadAll();

    /* Allocate a tempoary scene data structure
     */
    aiScene* tempScene = new aiScene();
    tempScene->mRootNode = new aiNode();
    tempScene->mRootNode->mName.Set("<IRRRoot>");

    /* Copy the cameras to the output array
     */
    if (!cameras.empty())   {
        tempScene->mNumCameras = (unsigned int)cameras.size();
        tempScene->mCameras = new aiCamera*[tempScene->mNumCameras];
        ::memcpy(tempScene->mCameras,&cameras[0],sizeof(void*)*tempScene->mNumCameras);
    }

    /* Copy the light sources to the output array
     */
    if (!lights.empty())    {
        tempScene->mNumLights = (unsigned int)lights.size();
        tempScene->mLights = new aiLight*[tempScene->mNumLights];
        ::memcpy(tempScene->mLights,&lights[0],sizeof(void*)*tempScene->mNumLights);
    }

    // temporary data
    std::vector< aiNodeAnim*>       anims;
    std::vector< aiMaterial*>       materials;
    std::vector< AttachmentInfo >   attach;
    std::vector<aiMesh*>            meshes;

    // try to guess how much storage we'll need
    anims.reserve     (guessedAnimCnt + (guessedAnimCnt >> 2));
    meshes.reserve    (guessedMeshCnt + (guessedMeshCnt >> 2));
    materials.reserve (guessedMatCnt  + (guessedMatCnt >> 2));

    /* Now process our scenegraph recursively: generate final
     * meshes and generate animation channels for all nodes.
     */
    unsigned int defMatIdx = UINT_MAX;
    GenerateGraph(root,tempScene->mRootNode, tempScene,
        batch, meshes, anims, attach, materials, defMatIdx);

    if (!anims.empty())
    {
        tempScene->mNumAnimations = 1;
        tempScene->mAnimations = new aiAnimation*[tempScene->mNumAnimations];
        aiAnimation* an = tempScene->mAnimations[0] = new aiAnimation();

        // ***********************************************************
        // This is only the global animation channel of the scene.
        // If there are animated models, they will have separate
        // animation channels in the scene. To display IRR scenes
        // correctly, users will need to combine the global anim
        // channel with all the local animations they want to play
        // ***********************************************************
        an->mName.Set("Irr_GlobalAnimChannel");

        // copy all node animation channels to the global channel
        an->mNumChannels = (unsigned int)anims.size();
        an->mChannels = new aiNodeAnim*[an->mNumChannels];
        ::memcpy(an->mChannels, & anims [0], sizeof(void*)*an->mNumChannels);
    }
    if (!meshes.empty())    {
        // copy all meshes to the temporary scene
        tempScene->mNumMeshes = (unsigned int)meshes.size();
        tempScene->mMeshes = new aiMesh*[tempScene->mNumMeshes];
        ::memcpy(tempScene->mMeshes,&meshes[0],tempScene->mNumMeshes*
            sizeof(void*));
    }

    /* Copy all materials to the output array
     */
    if (!materials.empty()) {
        tempScene->mNumMaterials = (unsigned int)materials.size();
        tempScene->mMaterials = new aiMaterial*[tempScene->mNumMaterials];
        ::memcpy(tempScene->mMaterials,&materials[0],sizeof(void*)*
            tempScene->mNumMaterials);
    }

    /*  Now merge all sub scenes and attach them to the correct
     *  attachment points in the scenegraph.
     */
    SceneCombiner::MergeScenes(&pScene,tempScene,attach,
        AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES | (!configSpeedFlag ? (
        AI_INT_MERGE_SCENE_GEN_UNIQUE_NAMES_IF_NECESSARY | AI_INT_MERGE_SCENE_GEN_UNIQUE_MATNAMES) : 0));


    /*  If we have no meshes | no materials now set the INCOMPLETE
     *  scene flag. This is necessary if we failed to load all
     *  models from external files
     */
    if (!pScene->mNumMeshes || !pScene->mNumMaterials)  {
        ASSIMP_LOG_WARN("IRR: No meshes loaded, setting AI_SCENE_FLAGS_INCOMPLETE");
        pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
    }

    /* Finished ... everything destructs automatically and all
     * temporary scenes have already been deleted by MergeScenes()
     */

    delete root;
}

#endif // !! ASSIMP_BUILD_NO_IRR_IMPORTER