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

#ifndef ASSIMP_BUILD_NO_IRR_IMPORTER

#include "AssetLib/Irr/IRRLoader.h"
#include "Common/Importer.h"

#include <assimp/GenericProperty.h>
#include <assimp/MathFunctions.h>
#include <assimp/ParsingUtils.h>
#include <assimp/SceneCombiner.h>
#include <assimp/StandardShapes.h>
#include <assimp/fast_atof.h>
#include <assimp/importerdesc.h>
#include <assimp/material.h>
#include <assimp/mesh.h>
#include <assimp/postprocess.h>
#include <assimp/scene.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/IOSystem.hpp>

#include <memory>

using namespace Assimp;

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() = default;

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

// ------------------------------------------------------------------------------------------------
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 that 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;
}

// ------------------------------------------------------------------------------------------------
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 ...
	// This also applies to the above function of FindSuitableMultiple and ClampSpline which are
	// solely used in this function

	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;


				// 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)) {
	if (nullptr == mat) {
		return;
	}

    // 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 *localScene = batch.GetImport(root->id);
			if (!localScene) {
				ASSIMP_LOG_ERROR("IRR: Unable to load external file: ", root->meshPath);
				break;
			}
			attach.emplace_back(localScene, 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)localScene->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 < localScene->mNumMaterials; ++i) {
				// Delete the old material, we don't need it anymore
				delete localScene->mMaterials[i];

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

			// NOTE: Each mesh should have exactly one material assigned,
			// but we do it in a separate loop if this behavior changes
			// in future.
			for (unsigned int i = 0; i < localScene->mNumMeshes; ++i) {
				// Process material flags
				aiMesh *mesh = localScene->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 light-map, normal-map, 2layered material) we need to
				// setup the correct UV index for it. The texture can either
				// be diffuse (light-map & 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 polygons on a specific axis. Just
			// use some hard-coded 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 sky-box 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 sky-box
			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
	XmlParser st;
    if (!st.parse( file.get() )) {
        throw DeadlyImportError("XML parse error while loading IRR file ", pFile);
    }
    pugi::xml_node rootElement = st.getRootNode();

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

	// Current node parent
	Node *curParent = root;

	// Scene-graph 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())  {
	for (pugi::xml_node child : rootElement.children())
		switch (child.type()) {
			case pugi::node_element:
				if (!ASSIMP_stricmp(child.name(), "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");
					pugi::xml_attribute attrib = child.attribute("type");
					Node *nd;
					if (!ASSIMP_stricmp(attrib.name(), "mesh") || !ASSIMP_stricmp(attrib.name(), "octTree")) {
						// OctTree's and meshes are treated equally
						nd = new Node(Node::MESH);
					} else if (!ASSIMP_stricmp(attrib.name(), "cube")) {
						nd = new Node(Node::CUBE);
						++guessedMeshCnt;
					} else if (!ASSIMP_stricmp(attrib.name(), "skybox")) {
						nd = new Node(Node::SKYBOX);
						guessedMeshCnt += 6;
					} else if (!ASSIMP_stricmp(attrib.name(), "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(attrib.name(), "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(attrib.name(), "sphere")) {
						nd = new Node(Node::SPHERE);
						++guessedMeshCnt;
					} else if (!ASSIMP_stricmp(attrib.name(), "animatedMesh")) {
						nd = new Node(Node::ANIMMESH);
					} else if (!ASSIMP_stricmp(attrib.name(), "empty")) {
						nd = new Node(Node::DUMMY);
					} else if (!ASSIMP_stricmp(attrib.name(), "terrain")) {
						nd = new Node(Node::TERRAIN);
					} else if (!ASSIMP_stricmp(attrib.name(), "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: ", attrib.name());

						/*  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 scene-graph
                     */
					curNode = nd;
					nd->parent = curParent;
					curParent->children.push_back(nd);
				} else if (!ASSIMP_stricmp(child.name(), "materials")) {
					inMaterials = true;
				} else if (!ASSIMP_stricmp(child.name(), "animators")) {
					inAnimator = true;
				} else if (!ASSIMP_stricmp(child.name(), "attributes")) {
					//  We should have a valid node here
					//  FIX: no ... the scene root node is also contained in an attributes block
					if (!curNode) {
						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.emplace_back();
						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.emplace_back();
						curAnim = &curNode->animators.back();

						++guessedAnimCnt;
					}

					/*  Parse all elements in the attributes block
                     *  and process them.
                     */
					//					while (reader->read()) {
					for (pugi::xml_node attrib : child.children()) {
						if (attrib.type() == pugi::node_element) {
							//if (reader->getNodeType() == EXN_ELEMENT) {
							//if (!ASSIMP_stricmp(reader->getNodeName(), "vector3d")) {
							if (!ASSIMP_stricmp(attrib.name(), "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.emplace_back();
											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")) {
							} else if (!ASSIMP_stricmp(attrib.name(), "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")) {
							} else if (!ASSIMP_stricmp(attrib.name(), "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")) {
							} else if (!ASSIMP_stricmp(attrib.name(), "int")) {
								IntProperty prop;
								ReadIntProperty(prop);

								if (inAnimator) {
									if (curAnim->type == Animator::FLY_STRAIGHT && prop.name == "TimeForWay") {
										curAnim->timeForWay = prop.value;
									}
								} else {
									// sphere polygon 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")) {
							} else if (!ASSIMP_stricmp(attrib.name(), "string") || !ASSIMP_stricmp(attrib.name(), "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")) {
						} else if (attrib.type() == pugi::node_null && !ASSIMP_stricmp(attrib.name(), "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 temporary 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 scene-graph 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
