assimp/code/LWSLoader.cpp

/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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* Redistributions of source code must retain the above
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  following disclaimer.

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  derived from this software without specific prior
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*/

/** @file  LWSLoader.cpp
 *  @brief Implementation of the LWS importer class 
 */

#include "AssimpPCH.h"

#include "LWSLoader.h"
#include "ParsingUtils.h"
#include "fast_atof.h"

#include "SceneCombiner.h"
#include "GenericProperty.h"
#include "SkeletonMeshBuilder.h"
#include "ConvertToLHProcess.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Recursive parsing of LWS files
void LWS::Element::Parse (const char*& buffer)
{
	for (;SkipSpacesAndLineEnd(&buffer);SkipLine(&buffer)) {
	
		// begin of a new element with children
		bool sub = false;
		if (*buffer == '{') {
			++buffer;
			SkipSpaces(&buffer);
			sub = true;
		}
		else if (*buffer == '}')
			return;

		children.push_back(Element());

		// copy data line - read token per token

		const char* cur = buffer;
		while (!IsSpaceOrNewLine(*buffer)) ++buffer;
		children.back().tokens[0] = std::string(cur,(size_t) (buffer-cur));
		SkipSpaces(&buffer);

		if (children.back().tokens[0] == "Plugin") 
		{
			DefaultLogger::get()->debug("LWS: Skipping over plugin-specific data");

			// strange stuff inside Plugin/Endplugin blocks. Needn't
			// follow LWS syntax, so we skip over it
			for (;SkipSpacesAndLineEnd(&buffer);SkipLine(&buffer)) {
				if (!::strncmp(buffer,"EndPlugin",9)) {
					//SkipLine(&buffer);
					break;
				}
			}
			continue;
		}

		cur = buffer;
		while (!IsLineEnd(*buffer)) ++buffer;
		children.back().tokens[1] = std::string(cur,(size_t) (buffer-cur));

		// parse more elements recursively
		if (sub)
			children.back().Parse(buffer);
	}
}

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
LWSImporter::LWSImporter()
{
	// nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
LWSImporter::~LWSImporter()
{
	// nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool LWSImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler,bool checkSig) const
{
	const std::string extension = GetExtension(pFile);
	if (extension == "lws" || extension == "mot")
		return true;

	// if check for extension is not enough, check for the magic tokens LWSC and LWMO
	if (!extension.length() || checkSig) {
		uint32_t tokens[2]; 
		tokens[0] = AI_MAKE_MAGIC("LWSC");
		tokens[1] = AI_MAKE_MAGIC("LWMO");
		return CheckMagicToken(pIOHandler,pFile,tokens,2);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Get list of file extensions
void LWSImporter::GetExtensionList(std::set<std::string>& extensions)
{
	extensions.insert("lws");
	extensions.insert("mot");
}

// ------------------------------------------------------------------------------------------------
// Setup configuration properties
void LWSImporter::SetupProperties(const Importer* pImp)
{
	// AI_CONFIG_FAVOUR_SPEED
	configSpeedFlag = (0 != pImp->GetPropertyInteger(AI_CONFIG_FAVOUR_SPEED,0));

	// AI_CONFIG_IMPORT_LWS_ANIM_START
	first = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_LWS_ANIM_START,
		150392 /* magic hack */);

	// AI_CONFIG_IMPORT_LWS_ANIM_END
	last = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_LWS_ANIM_END,
		150392 /* magic hack */);

	if (last < first) {
		std::swap(last,first);
	}
}

// ------------------------------------------------------------------------------------------------
// Read an envelope description
void LWSImporter::ReadEnvelope(const LWS::Element& dad, LWO::Envelope& fill )
{
	if (dad.children.empty()) {
		DefaultLogger::get()->error("LWS: Envelope descriptions must not be empty");	
		return;
	}

	// reserve enough storage
	std::list< LWS::Element >::const_iterator it = dad.children.begin();;
	fill.keys.reserve(strtol10(it->tokens[1].c_str()));

	for (++it; it != dad.children.end(); ++it) {
		const char* c = (*it).tokens[1].c_str();

		if ((*it).tokens[0] == "Key") {
			fill.keys.push_back(LWO::Key());
			LWO::Key& key = fill.keys.back();

			float f;
			SkipSpaces(&c);
			c = fast_atof_move(c,key.value);
			SkipSpaces(&c);
			c = fast_atof_move(c,f);

			key.time = f;

			unsigned int span = strtol10(c,&c), num = 0;
			switch (span) {
			
				case 0:
					key.inter = LWO::IT_TCB;
					num = 5;
					break;
				case 1:
				case 2:
					key.inter = LWO::IT_HERM;
					num = 5;
					break;
				case 3:
					key.inter = LWO::IT_LINE;
					num = 0;
					break;
				case 4:
					key.inter = LWO::IT_STEP;
					num = 0;
					break;
				case 5:
					key.inter = LWO::IT_BEZ2;
					num = 4;
					break;
				default:
					DefaultLogger::get()->error("LWS: Unknown span type");
			}
			for (unsigned int i = 0; i < num;++i) {
				SkipSpaces(&c);
				c = fast_atof_move(c,key.params[i]);
			}
		}
		else if ((*it).tokens[0] == "Behaviors") {
			SkipSpaces(&c);
			fill.pre = (LWO::PrePostBehaviour) strtol10(c,&c);
			SkipSpaces(&c);
			fill.post = (LWO::PrePostBehaviour) strtol10(c,&c);
		}
	}
}

// ------------------------------------------------------------------------------------------------
// Read animation channels in the old LightWave animation format
void LWSImporter::ReadEnvelope_Old(
	std::list< LWS::Element >::const_iterator& it, 
	const std::list< LWS::Element >::const_iterator& end,
	LWS::NodeDesc& nodes,
	unsigned int version)
{
	unsigned int num,sub_num;
	if (++it == end)goto unexpected_end;

	num = strtol10((*it).tokens[0].c_str());
	for (unsigned int i = 0; i < num; ++i) {
	
		nodes.channels.push_back(LWO::Envelope());
		LWO::Envelope& envl = nodes.channels.back();

		envl.index = i;
		envl.type  = (LWO::EnvelopeType)(i+1);
	
		if (++it == end)goto unexpected_end;
		sub_num = strtol10((*it).tokens[0].c_str());

		for (unsigned int n = 0; n < sub_num;++n) {

			if (++it == end)goto unexpected_end;

			// parse value and time, skip the rest for the moment.
			LWO::Key key;
			const char* c = fast_atof_move((*it).tokens[0].c_str(),key.value);
			SkipSpaces(&c);
			float f;
			fast_atof_move((*it).tokens[0].c_str(),f);
			key.time = f;

			envl.keys.push_back(key);
		}
	}
	return;

unexpected_end:
	DefaultLogger::get()->error("LWS: Encountered unexpected end of file while parsing object motion");
}

// ------------------------------------------------------------------------------------------------
// Setup a nice name for a node 
void LWSImporter::SetupNodeName(aiNode* nd, LWS::NodeDesc& src)
{
	const unsigned int combined = src.number | ((unsigned int)src.type) << 28u;

	// the name depends on the type. We break LWS's strange naming convention
	// and return human-readable, but still machine-parsable and unique, strings.
	if (src.type == LWS::NodeDesc::OBJECT)	{

		if (src.path.length()) {
			std::string::size_type s = src.path.find_last_of("\\/");
			if (s == std::string::npos)
				s = 0;
			else ++s;

			nd->mName.length = ::sprintf(nd->mName.data,"%s_(%08X)",src.path.substr(s).c_str(),combined);
			return;
		}
	}
	nd->mName.length = ::sprintf(nd->mName.data,"%s_(%08X)",src.name,combined);
}

// ------------------------------------------------------------------------------------------------
// Recursively build the scenegraph
void LWSImporter::BuildGraph(aiNode* nd, LWS::NodeDesc& src, std::vector<AttachmentInfo>& attach,
	BatchLoader& batch,
	aiCamera**& camOut,
	aiLight**& lightOut, 
	std::vector<aiNodeAnim*>& animOut)
{
	// Setup a very cryptic name for the node, we want the user to be happy
	SetupNodeName(nd,src);

	// If this is an object from an external file - get the scene and setup proper attachment tags
	aiScene* obj = NULL;
	if (src.type == LWS::NodeDesc::OBJECT && src.path.length() ) {
		obj = batch.GetImport(src.id);
		if (!obj) {
			DefaultLogger::get()->error("LWS: Failed to read external file " + src.path);
		}
		else {
			attach.push_back(AttachmentInfo(obj,nd));
		}
	}

	// If object is a light source - setup a corresponding ai structure
	else if (src.type == LWS::NodeDesc::LIGHT) {
		aiLight* lit = *lightOut++ = new aiLight();

		// compute final light color
		lit->mColorDiffuse = lit->mColorSpecular = src.lightColor*src.lightIntensity;

		// name to attach light to node -> unique due to LWs indexing system
		lit->mName = nd->mName;

		// detemine light type and setup additional members
		if (src.lightType == 2) { /* spot light */

			lit->mType = aiLightSource_SPOT;
			lit->mAngleInnerCone = (float)AI_DEG_TO_RAD( src.lightConeAngle );
			lit->mAngleOuterCone = lit->mAngleInnerCone+(float)AI_DEG_TO_RAD( src.lightEdgeAngle );

		}
		else if (src.lightType == 1) { /* directional light source */
			lit->mType = aiLightSource_DIRECTIONAL;
		}
		else lit->mType = aiLightSource_POINT;

		// fixme: no proper handling of light falloffs yet
		if (src.lightFalloffType == 1)
			lit->mAttenuationConstant = 1.f;
		else if (src.lightFalloffType == 1)
			lit->mAttenuationLinear = 1.f;
		else 
			lit->mAttenuationQuadratic = 1.f;
	}

	// If object is a camera - setup a corresponding ai structure
	else if (src.type == LWS::NodeDesc::CAMERA) {
		aiCamera* cam = *camOut++ = new aiCamera();

		// name to attach cam to node -> unique due to LWs indexing system
		cam->mName = nd->mName;
	}

	// Get the node transformation from the LWO key
	LWO::AnimResolver resolver(src.channels,fps);
	resolver.ExtractBindPose(nd->mTransformation);

	// .. and construct animation channels
	aiNodeAnim* anim = NULL;

	if (first != last) {
		resolver.SetAnimationRange(first,last);
		resolver.ExtractAnimChannel(&anim,AI_LWO_ANIM_FLAG_SAMPLE_ANIMS|AI_LWO_ANIM_FLAG_START_AT_ZERO);
		if (anim) {
			anim->mNodeName = nd->mName;
			animOut.push_back(anim);
		}
	}

	// process pivot point, if any
	if (src.pivotPos != aiVector3D()) {
		aiMatrix4x4 tmp;
		aiMatrix4x4::Translation(-src.pivotPos,tmp);

		if (anim) {
		
			// We have an animation channel for this node. Problem: to combine the pivot
			// point with the node anims, we'd need to interpolate *all* keys, get 
			// transformation matrices from them, apply the translation and decompose
			// the resulting matrices again in order to reconstruct the keys. This 
			// solution here is *much* easier ... we're just inserting an extra node
			// in the hierarchy.
			// Maybe the final optimization here will be done during postprocessing.

			aiNode* pivot = new aiNode();
			pivot->mName.length = sprintf( pivot->mName.data, "$Pivot_%s",nd->mName.data);
			pivot->mTransformation = tmp;

			pivot->mChildren = new aiNode*[pivot->mNumChildren = 1];
			pivot->mChildren[0] = nd;

			pivot->mParent = nd->mParent;
			nd->mParent    = pivot;
			
			// swap children and hope the parents wont see a huge difference
			pivot->mParent->mChildren[pivot->mParent->mNumChildren-1] = pivot;
		}
		else {
			nd->mTransformation = tmp*nd->mTransformation;
		}
	}

	// Add children
	if (src.children.size()) {
		nd->mChildren = new aiNode*[src.children.size()];
		for (std::list<LWS::NodeDesc*>::iterator it = src.children.begin(); it != src.children.end(); ++it) {
			aiNode* ndd = nd->mChildren[nd->mNumChildren++] = new aiNode();
			ndd->mParent = nd;

			BuildGraph(ndd,**it,attach,batch,camOut,lightOut,animOut);
		}
	}
}

// ------------------------------------------------------------------------------------------------
// Determine the exact location of a LWO file
std::string LWSImporter::FindLWOFile(const std::string& in)
{
	// insert missing directory seperator if necessary
	std::string tmp;
	if (in.length() > 3 && in[1] == ':'&& in[2] != '\\' && in[2] != '/')
	{
		tmp = in[0] + ":\\" + in.substr(2);
	}
	else tmp = in;

	if (io->Exists(tmp))
		return in;

	// file is not accessible for us ... maybe it's packed by 
	// LightWave's 'Package Scene' command?

	// Relevant for us are the following two directories:
	// <folder>\Objects\<hh>\<*>.lwo
	// <folder>\Scenes\<hh>\<*>.lws
	// where <hh> is optional.

	std::string test = ".." + io->getOsSeparator() + tmp; 
	if (io->Exists(test))
		return test;

	test = ".." + io->getOsSeparator() + test; 
	if (io->Exists(test))
		return test;

	// return original path, maybe the IOsystem knows better
	return tmp;
}

// ------------------------------------------------------------------------------------------------
// Read file into given scene data structure
void LWSImporter::InternReadFile( const std::string& pFile, aiScene* pScene, 
	IOSystem* pIOHandler)
{
	io = pIOHandler;
	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile, "rb"));

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

	// Allocate storage and copy the contents of the file to a memory buffer
	std::vector< char > mBuffer;
	TextFileToBuffer(file.get(),mBuffer);
	
	// Parse the file structure
	LWS::Element root; const char* dummy = &mBuffer[0];
	root.Parse(dummy);

	// Construct a Batchimporter to read more files recursively
	BatchLoader batch(pIOHandler);
//	batch.SetBasePath(pFile);

	// Construct an array to receive the flat output graph
	std::list<LWS::NodeDesc> nodes;

	unsigned int cur_light = 0, cur_camera = 0, cur_object = 0;
	unsigned int num_light = 0, num_camera = 0, num_object = 0;

	// check magic identifier, 'LWSC'
	bool motion_file = false;
	std::list< LWS::Element >::const_iterator it = root.children.begin();
	
	if ((*it).tokens[0] == "LWMO")
		motion_file = true;

	if ((*it).tokens[0] != "LWSC" && !motion_file)
		throw DeadlyImportError("LWS: Not a LightWave scene, magic tag LWSC not found");

	// get file format version and print to log
	++it;
	unsigned int version = strtol10((*it).tokens[0].c_str());
	DefaultLogger::get()->info("LWS file format version is " + (*it).tokens[0]);
	first = 0.;
	last  = 60.;
	fps   = 25.; /* seems to be a good default frame rate */

	// Now read all elements in a very straghtforward manner
	for (; it != root.children.end(); ++it) {
		const char* c = (*it).tokens[1].c_str();

		// 'FirstFrame': begin of animation slice
		if ((*it).tokens[0] == "FirstFrame") {
			if (150392. != first           /* see SetupProperties() */)
				first = strtol10(c,&c)-1.; /* we're zero-based */
		}

		// 'LastFrame': end of animation slice
		else if ((*it).tokens[0] == "LastFrame") {
			if (150392. != last      /* see SetupProperties() */)
				last = strtol10(c,&c)-1.; /* we're zero-based */
		}

		// 'FramesPerSecond': frames per second
		else if ((*it).tokens[0] == "FramesPerSecond") {
			fps = strtol10(c,&c);
		}

		// 'LoadObjectLayer': load a layer of a specific LWO file
		else if ((*it).tokens[0] == "LoadObjectLayer") {

			// get layer index
			const int layer = strtol10(c,&c);

			// setup the layer to be loaded
			BatchLoader::PropertyMap props;
			SetGenericProperty(props.ints,AI_CONFIG_IMPORT_LWO_ONE_LAYER_ONLY,layer);

			// add node to list
			LWS::NodeDesc d;
			d.type = LWS::NodeDesc::OBJECT;
			if (version >= 4) { // handle LWSC 4 explicit ID
				SkipSpaces(&c);
				d.number = strtol16(c,&c) & AI_LWS_MASK;
			}
			else d.number = cur_object++;

			// and add the file to the import list
			SkipSpaces(&c);
			std::string path = FindLWOFile( c );
			d.path = path;
			d.id = batch.AddLoadRequest(path,0,&props);

			nodes.push_back(d);
			num_object++;
		}
		// 'LoadObject': load a LWO file into the scenegraph
		else if ((*it).tokens[0] == "LoadObject") {
			
			// add node to list
			LWS::NodeDesc d;
			d.type = LWS::NodeDesc::OBJECT;
			
			if (version >= 4) { // handle LWSC 4 explicit ID
				d.number = strtol16(c,&c) & AI_LWS_MASK;
				SkipSpaces(&c);
			}
			else d.number = cur_object++;
			std::string path = FindLWOFile( c );
			d.id = batch.AddLoadRequest(path,0,NULL);

			d.path = path;
			nodes.push_back(d);
			num_object++;
		}
		// 'AddNullObject': add a dummy node to the hierarchy
		else if ((*it).tokens[0] == "AddNullObject") {

			// add node to list
			LWS::NodeDesc d;
			d.type = LWS::NodeDesc::OBJECT;
			d.name = c;
			if (version >= 4) { // handle LWSC 4 explicit ID
				d.number = strtol16(c,&c) & AI_LWS_MASK;
			}
			else d.number = cur_object++;
			nodes.push_back(d);

			num_object++;
		}
		// 'NumChannels': Number of envelope channels assigned to last layer
		else if ((*it).tokens[0] == "NumChannels") {
			// ignore for now
		}
		// 'Channel': preceedes any envelope description
		else if ((*it).tokens[0] == "Channel") {
			if (nodes.empty()) {
				if (motion_file) {

					// LightWave motion file. Add dummy node
					LWS::NodeDesc d;
					d.type = LWS::NodeDesc::OBJECT;
					d.name = c;
					d.number = cur_object++;
					nodes.push_back(d);
				}
				else DefaultLogger::get()->error("LWS: Unexpected keyword: \'Channel\'");
			}

			// important: index of channel
			nodes.back().channels.push_back(LWO::Envelope());
			LWO::Envelope& env = nodes.back().channels.back();
			
			env.index = strtol10(c);

			// currently we can just interpret the standard channels 0...9
			// (hack) assume that index-i yields the binary channel type from LWO
			env.type = (LWO::EnvelopeType)(env.index+1);

		}
		// 'Envelope': a single animation channel
		else if ((*it).tokens[0] == "Envelope") {
			if (nodes.empty() || nodes.back().channels.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'Envelope\'");
			else {
				ReadEnvelope((*it),nodes.back().channels.back());
			}
		}
		// 'ObjectMotion': animation information for older lightwave formats
		else if (version < 3  && ((*it).tokens[0] == "ObjectMotion" ||
			(*it).tokens[0] == "CameraMotion" ||
			(*it).tokens[0] == "LightMotion")) {

			if (nodes.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'<Light|Object|Camera>Motion\'");
			else {
				ReadEnvelope_Old(it,root.children.end(),nodes.back(),version);
			}
		}
		// 'Pre/PostBehavior': pre/post animation behaviour for LWSC 2
		else if (version == 2 && (*it).tokens[0] == "Pre/PostBehavior") {
			if (nodes.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'Pre/PostBehavior'");
			else {
				for (std::list<LWO::Envelope>::iterator it = nodes.back().channels.begin(); it != nodes.back().channels.end(); ++it) {
					// two ints per envelope
					LWO::Envelope& env = *it;
					env.pre  = (LWO::PrePostBehaviour) strtol10(c,&c); SkipSpaces(&c);
					env.post = (LWO::PrePostBehaviour) strtol10(c,&c); SkipSpaces(&c);
				}
			}
		}
		// 'ParentItem': specifies the parent of the current element
		else if ((*it).tokens[0] == "ParentItem") {
			if (nodes.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'ParentItem\'");

			else nodes.back().parent = strtol16(c,&c);
		}
		// 'ParentObject': deprecated one for older formats
		else if (version < 3 && (*it).tokens[0] == "ParentObject") {
			if (nodes.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'ParentObject\'");

			else { 
				nodes.back().parent = strtol10(c,&c) | (1u << 28u);
			}
		}
		// 'AddCamera': add a camera to the scenegraph
		else if ((*it).tokens[0] == "AddCamera") {

			// add node to list
			LWS::NodeDesc d;
			d.type = LWS::NodeDesc::CAMERA;

			if (version >= 4) { // handle LWSC 4 explicit ID
				d.number = strtol16(c,&c) & AI_LWS_MASK;
			}
			else d.number = cur_camera++;
			nodes.push_back(d);

			num_camera++;
		}
		// 'CameraName': set name of currently active camera
		else if ((*it).tokens[0] == "CameraName") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::CAMERA)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'CameraName\'");

			else nodes.back().name = c;
		}
		// 'AddLight': add a light to the scenegraph
		else if ((*it).tokens[0] == "AddLight") {

			// add node to list
			LWS::NodeDesc d;
			d.type = LWS::NodeDesc::LIGHT;

			if (version >= 4) { // handle LWSC 4 explicit ID
				d.number = strtol16(c,&c) & AI_LWS_MASK;
			}
			else d.number = cur_light++;
			nodes.push_back(d);

			num_light++;
		}
		// 'LightName': set name of currently active light
		else if ((*it).tokens[0] == "LightName") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightName\'");

			else nodes.back().name = c;
		}
		// 'LightIntensity': set intensity of currently active light
		else if ((*it).tokens[0] == "LightIntensity" || (*it).tokens[0] == "LgtIntensity" ) {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightIntensity\'");

			else fast_atof_move(c, nodes.back().lightIntensity );
			
		}
		// 'LightType': set type of currently active light
		else if ((*it).tokens[0] == "LightType") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightType\'");

			else nodes.back().lightType = strtol10(c);
			
		}
		// 'LightFalloffType': set falloff type of currently active light
		else if ((*it).tokens[0] == "LightFalloffType") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightFalloffType\'");

			else nodes.back().lightFalloffType = strtol10(c);
			
		}
		// 'LightConeAngle': set cone angle of currently active light
		else if ((*it).tokens[0] == "LightConeAngle") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightConeAngle\'");

			else nodes.back().lightConeAngle = fast_atof(c);
			
		}
		// 'LightEdgeAngle': set area where we're smoothing from min to max intensity
		else if ((*it).tokens[0] == "LightEdgeAngle") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightEdgeAngle\'");

			else nodes.back().lightEdgeAngle = fast_atof(c);
			
		}
		// 'LightColor': set color of currently active light
		else if ((*it).tokens[0] == "LightColor") {
			if (nodes.empty() || nodes.back().type != LWS::NodeDesc::LIGHT)
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'LightColor\'");

			else {
				c = fast_atof_move(c, (float&) nodes.back().lightColor.r );
				SkipSpaces(&c);
				c = fast_atof_move(c, (float&) nodes.back().lightColor.g );
				SkipSpaces(&c);
				c = fast_atof_move(c, (float&) nodes.back().lightColor.b );
			}
		}

		// 'PivotPosition': position of local transformation origin
		else if ((*it).tokens[0] == "PivotPosition" || (*it).tokens[0] == "PivotPoint") {
			if (nodes.empty())
				DefaultLogger::get()->error("LWS: Unexpected keyword: \'PivotPosition\'");
			else {
				c = fast_atof_move(c, (float&) nodes.back().pivotPos.x );
				SkipSpaces(&c);
				c = fast_atof_move(c, (float&) nodes.back().pivotPos.y );
				SkipSpaces(&c);
				c = fast_atof_move(c, (float&) nodes.back().pivotPos.z );
			}
		}
	}

	// resolve parenting
	for (std::list<LWS::NodeDesc>::iterator it = nodes.begin(); it != nodes.end(); ++it) {
	
		// check whether there is another node which calls us a parent
		for (std::list<LWS::NodeDesc>::iterator dit = nodes.begin(); dit != nodes.end(); ++dit) {
			if (dit != it && *it == (*dit).parent) {
				if ((*dit).parent_resolved) {
					// fixme: it's still possible to produce an overflow due to cross references ..
					DefaultLogger::get()->error("LWS: Found cross reference in scenegraph");
					continue;
				}

				(*it).children.push_back(&*dit);
				(*dit).parent_resolved = &*it;
			}
		}
	}

	// find out how many nodes have no parent yet
	unsigned int no_parent = 0;
	for (std::list<LWS::NodeDesc>::iterator it = nodes.begin(); it != nodes.end(); ++it) {
		if (!(*it).parent_resolved)
			++ no_parent;
	}
	if (!no_parent)
		throw DeadlyImportError("LWS: Unable to find scene root node");


	// Load all subsequent files
	batch.LoadAll();

	// and build the final output graph by attaching the loaded external
	// files to ourselves. first build a master graph 
	aiScene* master = new aiScene();
	aiNode* nd = master->mRootNode = new aiNode();

	// allocate storage for cameras&lights
	if (num_camera) {
		master->mCameras = new aiCamera*[master->mNumCameras = num_camera];
	}
	aiCamera** cams = master->mCameras;
	if (num_light) {
		master->mLights = new aiLight*[master->mNumLights = num_light];
	}
	aiLight** lights = master->mLights;

	std::vector<AttachmentInfo> attach;
	std::vector<aiNodeAnim*> anims;

	nd->mName.Set("<LWSRoot>");
	nd->mChildren = new aiNode*[no_parent];
	for (std::list<LWS::NodeDesc>::iterator it = nodes.begin(); it != nodes.end(); ++it) {
		if (!(*it).parent_resolved) {
			aiNode* ro = nd->mChildren[ nd->mNumChildren++ ] = new aiNode();
			ro->mParent = nd;

			// ... and build the scene graph. If we encounter object nodes,
			// add then to our attachment table.
			BuildGraph(ro,*it, attach, batch, cams, lights, anims);
		}
	}

	// create a master animation channel for us
	if (anims.size()) {
		master->mAnimations = new aiAnimation*[master->mNumAnimations = 1];
		aiAnimation* anim = master->mAnimations[0] = new aiAnimation();
		anim->mName.Set("LWSMasterAnim");

		// LWS uses seconds as time units, but we convert to frames
		anim->mTicksPerSecond = fps;
		anim->mDuration = last-(first-1); /* fixme ... zero or one-based?*/

		anim->mChannels = new aiNodeAnim*[anim->mNumChannels = anims.size()];
		std::copy(anims.begin(),anims.end(),anim->mChannels);
	}

	// convert the master scene to RH
	MakeLeftHandedProcess monster_cheat;
	monster_cheat.Execute(master);

	// .. ccw
	FlipWindingOrderProcess flipper;
	flipper.Execute(pScene);

	// OK ... finally build the output graph
	SceneCombiner::MergeScenes(&pScene,master,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));

	// Check flags
	if (!pScene->mNumMeshes || !pScene->mNumMaterials) {
		pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;

		if (pScene->mNumAnimations) {
			// construct skeleton mesh
			SkeletonMeshBuilder builder(pScene);
		}
	}

}