vrml2mesh.cpp

赫赫大名的 OGRE 游戏引擎

#include "stdafx.h"

struct vertex {
	int pos, tc, normal, colour;

	bool operator<(const vertex &v) const {
		if (pos < v.pos) return true;
		if (pos > v.pos) return false;
		if (normal < v.normal) return true;
		if (normal > v.normal) return false;
		if (tc < v.tc) return true;
		if (tc > v.tc) return false;
		return colour < v.colour;
	}
};

// VRML face
struct face {
	std::vector<int> indices;
};

// OGRE face
struct triangle {
	int vertices[3];
};

typedef std::vector<Vector3> Vec3Vec;
typedef std::vector<vertex> VertVec;
typedef std::vector<face> FaceVec;
typedef std::vector<triangle> TriVec;
typedef std::vector<int> IntVec;
typedef std::map<vertex, int> VertMap;

// traverse the scene graph looking for Shapes
void parseFile(Mesh *, const vrmllib::file &);
void parseNode(Mesh *, const vrmllib::node *, Matrix4 = Matrix4::IDENTITY);

// generate a SubMesh from a Shape
void parseShape(Mesh *, const Shape *, Matrix4);

	// helpers:
	Ogre::Material *parseMaterial(const Appearance *, const String &name);
	void parseFaces(FaceVec &, const IndexedFaceSet *);
	void triangulateAndExpand(TriVec &, VertVec &, const FaceVec &, const Shape *);
	void copyToSubMesh(SubMesh *, const TriVec &, const VertVec &, const Shape *, const Matrix4 &);

// get the array index for a VRML vertex property
int getIndex(const IntVec &coordIndex, const IntVec &, bool perVertex, int facenr, int vertnr);

// used by findName*
typedef std::map<const vrmllib::node *, String> NameMap;
NameMap gNameMap;

// find name of DEFined node
const String *findName(const vrmllib::node *n);
const String *findNameRecursive(const vrmllib::node *n);

String gBaseName; // base name of the input file (no path or extension)

// conversion functions:
inline Vector3 vec(const vrmllib::vec3 &v) { return Vector3(v.x, v.y, v.z); }
inline ColourValue col(const vrmllib::col3 &c) { return ColourValue(c.r, c.g, c.b); }
inline void copyVec(Real *d, const Vector3 &s) { d[0] = s.x; d[1] = s.y; d[2] = s.z; }
inline void copyVec(Real *d, const vec2 &s) { d[0] = s.x; d[1] = s.y; }

Matrix4 transMat(vrmllib::vec3, bool inverse = false);
Matrix4 scaleMat(vrmllib::vec3, bool inverse = false);
Matrix4 rotMat(vrmllib::rot, bool inverse = false);

int main(int argc, char **argv)
{
try
{
	String inname, outname, path;

	if (argc != 2 && argc != 3)
		throw
			"Wrong number of arguments.\n"
			"	Usage: VRML2mesh <input vrml file> [output mesh file]";

	inname = argv[1];

	// get base name
	gBaseName = inname;
	size_t p = gBaseName.find_last_of("/\\");
	if (p != gBaseName.npos) {
		path.assign(gBaseName, 0, p+1);
		gBaseName.erase(0, p+1);
	}
	p = gBaseName.rfind('.');
	if (p != gBaseName.npos)
		gBaseName.erase(p);

	if (argc == 3)
		outname = argv[2];
	else
		outname = path + gBaseName + ".mesh";

	LogManager log;
	log.createLog(path + "VRML2mesh.log");

	Math math;
	MaterialManager materialMgr;
	MeshSerializer meshSer;

	Mesh mesh("conversionTarget");

	try {
		log.logMessage("Reading " + inname);

		// read VRML file
		std::ifstream infile(inname.c_str());
		if (!infile.is_open())
			throw "failed to open input file";

		vrmllib::file vfile(infile);
		log.logMessage("Finished parsing VRML file");

		// populate name map
		for (vrmllib::file::defs_t::iterator i=vfile.defs.begin(), e=vfile.defs.end(); i!=e; ++i)
			gNameMap[i->second] = i->first;

		// search from SubMeshes
		parseFile(&mesh, vfile);

		if (mesh.getNumSubMeshes() == 0)
			throw "No SubMeshes were generated, aborting.";

		log.logMessage("Exporting Mesh");
		meshSer.exportMesh(&mesh, outname, true);

		log.logMessage("Done.");
	}
	catch (const char *e) {
		log.logMessage(LML_NORMAL, "Error: %s", e);
		return 1;
	}
	catch (std::exception &e) {
		log.logMessage(LML_NORMAL, "Exception: %s", e.what());
		return 1;
	}
	catch (Exception &e) {
		log.logMessage("Exception: " + e.getFullDescription());
		return 1;
	}
}
catch (Exception &e) {
	std::cerr << "Exception: " << e.getFullDescription() << std::endl;
	return 1;
}
catch (const char *e) {
	std::cerr << e << std::endl;
	return 1;
}
}

void parseFile(Mesh *mesh, const vrmllib::file &file)
{
	for (vrmllib::file::roots_t::const_iterator i=file.roots.begin(), e=file.roots.end(); i!=e; ++i)
		parseNode(mesh, *i);
}

void parseNode(Mesh *mesh, const vrmllib::node *n, Matrix4 m)
{
	if (const Transform *tr = dynamic_cast<const Transform *>(n)) {
		// TODO: handle center, scaleOrientation

		Matrix4 trans;
		trans.makeTrans(vec(tr->translation));

		Matrix4 scale = Matrix4::IDENTITY;
		scale[0][0] = tr->scale.x;
		scale[1][1] = tr->scale.y;
		scale[2][2] = tr->scale.z;

		Matrix3 rot3;
		rot3.FromAxisAngle(vec(tr->rotation.vector), tr->rotation.radians);
		Matrix4 rot = Matrix4::IDENTITY;
		rot = rot3;

		m = m * transMat(tr->translation) * transMat(tr->center)
			* rotMat(tr->rotation) * rotMat(tr->scaleOrientation) * scaleMat(tr->scale)
			* rotMat(tr->scaleOrientation, true) * transMat(tr->center, true);
	}

	if (const grouping_node *gn = dynamic_cast<const grouping_node *>(n)) {
		for (std::vector<vrmllib::node *>::const_iterator
			i=gn->children.begin(), e=gn->children.end(); i!=e; ++i)
				parseNode(mesh, *i, m);

	} else if (const Shape *sh = dynamic_cast<const Shape *>(n))
		parseShape(mesh, sh, m);
}

void parseShape(Mesh *mesh, const Shape *sh, Matrix4 mat)
{
try
{
	LogManager &log = LogManager::getSingleton();
	log.logMessage("Found a Shape...");

	IndexedFaceSet *ifs = dynamic_cast<IndexedFaceSet *>(sh->geometry);
	if (!ifs)
		throw "Geometry was not an IndexedFaceSet, keep looking";

	Coordinate *coord = dynamic_cast<Coordinate *>(ifs->coord);
	if (!coord)
		throw "Invalid Coordinate node";
	if (coord->point.empty())
		throw "No coordinates found, ignoring this Shape";

	SubMesh *sub;
	if (const String *name = findNameRecursive(sh)) {
		log.logMessage("Creating SubMesh: " + *name);
		sub = mesh->createSubMesh(*name);
	} else {
		log.logMessage("Creating unnamed SubMesh");
		sub = mesh->createSubMesh();
	}

	Appearance *app = dynamic_cast<Appearance *>(sh->appearance);
	TextureCoordinate *tcs = dynamic_cast<TextureCoordinate *>(ifs->texCoord);
	Normal *norm = dynamic_cast<Normal *>(ifs->normal);
	Color *color = dynamic_cast<Color *>(ifs->color);

	String message = "Found: geometry";
	if (tcs)
		message += ", texcoords";
	if (norm)
		message += ", normals";
	if (color)
		message += ", colours";
	log.logMessage(message);

	if (!tcs && !norm && !color)
		log.logMessage("Warning: OGRE will refuse to render SubMeshes that have neither\n"
			"\ttexture coordinates, normals or vertex colours.");

	if (!norm) {
		log.logMessage("Warning: No normals found.\n"
			"\tVRML dictates that normals should be generated, but this program\n"
			"\tdoes not do so. If you want the resulting mesh to contain normals,\n"
			"\tmake sure they are exported.");
	}

	// process material
	static std::map<Appearance *, Ogre::Material *> matMap;

	Ogre::Material *&material = matMap[app];
	if (material && app) {
		log.logMessage("Using material " + material->getName());
		sub->setMaterialName(material->getName());
	} else {
		String matName;
		const String *mn;
		if (mn = findName(app))
			matName = *mn;
		else if (app && (mn = findName(app->material))) {
			static std::map<String, int> postfix;
			std::stringstream ss;
			int &num = postfix[*mn];
			ss << *mn << '/' << num++;
			matName = ss.str();
		} else {
			static int matNum;
			std::stringstream ss;
			ss << gBaseName << '/' << matNum++;
			matName = ss.str();
			log.logMessage("No material name found, using " + matName);
		}
		log.logMessage("Reading material " + matName);

		material = parseMaterial(app, matName);

		sub->setMaterialName(matName);
	}

	FaceVec faces;
	parseFaces(faces, ifs);

	VertVec vertices;
	TriVec triangles;

	log.logMessage("Processing geometry...");
	triangulateAndExpand(triangles, vertices, faces, sh);

	copyToSubMesh(sub, triangles, vertices, sh, mat);

	log.logMessage("Done with this SubMesh.");
}
catch (const char *e) {
	LogManager::getSingleton().logMessage(e);
}
}

void copyToSubMesh(SubMesh *sub, const TriVec &triangles, const VertVec &vertices,
	const Shape *sh, const Matrix4 &mat)
{
	IndexedFaceSet *ifs = dynamic_cast<IndexedFaceSet *>(sh->geometry);
	Coordinate *coord = dynamic_cast<Coordinate *>(ifs->coord);
	TextureCoordinate *tcs = dynamic_cast<TextureCoordinate *>(ifs->texCoord);
	Normal *norm = dynamic_cast<Normal *>(ifs->normal);
	Color *color = dynamic_cast<Color *>(ifs->color);

	int nvertices = vertices.size();
	int nfaces = triangles.size();

	GeometryData &geom = sub->geometry;
	sub->useSharedVertices = false;
	sub->numFaces = nfaces;
	sub->faceVertexIndices = new unsigned short[nfaces*3];

	geom.hasColours = color;
	geom.hasNormals = norm;
	geom.numTexCoords = tcs ? 1 : 0;
	geom.numTexCoordDimensions[0] = 2;
	geom.numVertices = nvertices;

	geom.pVertices = new Real[nvertices*3];
	if (tcs)
		geom.pTexCoords[0] = new Real[nvertices*2];
	if (norm)
		geom.pNormals = new Real[nvertices*3];
	if (color)
		geom.pColours = new unsigned long[nvertices];

	Matrix3 normMat;
	mat.extract3x3Matrix(normMat);
	normMat = normMat.Inverse().Transpose();

	// populate face list
	for (int i=0; i!=nfaces; ++i) {
		unsigned short *f = sub->faceVertexIndices + i*3;
		f[0] = triangles[i].vertices[0];
		f[1] = triangles[i].vertices[1];
		f[2] = triangles[i].vertices[2];
	}

	// populate vertex arrays
	for (int i=0; i!=nvertices; ++i) {
		const vertex &v = vertices[i];

		Real *pos = geom.pVertices + i*3;
		Real *tc = geom.pTexCoords[0] + i*2;
		Real *n = geom.pNormals + i*3;
		unsigned long *col = geom.pColours + i;

		copyVec(pos, mat * vec(coord->point[v.pos]));
		if (norm) {
			Vector3 t = normMat * vec(norm->vector[v.normal]);
			t.normalise();
			copyVec(n, t);
		}
		if (tcs)
			copyVec(tc, tcs->point[v.tc]);
		if (color) {
			col3 c = color->color[v.colour];
			ColourValue cv(c.r, c.g, c.b);
			*col = cv.getAsLongRGBA();
		}
	}
}

void triangulateAndExpand(TriVec &triangles, VertVec &vertices, const FaceVec &faces, const Shape *sh)
{
	IndexedFaceSet *ifs = dynamic_cast<IndexedFaceSet *>(sh->geometry);
	Coordinate *coord = dynamic_cast<Coordinate *>(ifs->coord);
	TextureCoordinate *tcs = dynamic_cast<TextureCoordinate *>(ifs->texCoord);
	Normal *norm = dynamic_cast<Normal *>(ifs->normal);
	Color *color = dynamic_cast<Color *>(ifs->color);

	VertMap vertexMap;

	// triangulate and expand vertices
	for (FaceVec::const_iterator f=faces.begin(), e=faces.end(); f!=e; ++f) {
		int faceNr = f - faces.begin();
		int triVertNr = 0;
		int triVerts[2] = { -1, -1 };
		for (IntVec::const_iterator i = f->indices.begin(), e=f->indices.end(); i!=e; ++i, ++triVertNr) {
			int triVertNr = i - f->indices.begin();
			int index = *i;

			vertex vert;

			// get full indices for vertex data
			vert.pos = ifs->coordIndex[index];
			vert.normal = norm ? getIndex(ifs->coordIndex, ifs->normalIndex,
				ifs->normalPerVertex, faceNr, index) : 0;
			vert.colour = color ? getIndex(ifs->coordIndex, ifs->colorIndex,
				ifs->colorPerVertex, faceNr, index) : 0;
			vert.tc = tcs ? getIndex(ifs->coordIndex, ifs->texCoordIndex,
				true, faceNr, index) : 0;

			// avoid duplication
			int nvert = vertexMap.size();
			int &vpos = vertexMap[vert];
			if (nvert != vertexMap.size()) {
				vpos = vertices.size();
				vertices.push_back(vert);
			}

			// emit triangle (maybe)
			if (triVertNr == 0)
				triVerts[0] = vpos;
			else if (triVertNr == 1)
				triVerts[1] = vpos;
			else {
				triangle t;
				t.vertices[0] = triVerts[0];
				t.vertices[1] = triVerts[1];
				t.vertices[2] = vpos;

				if (!ifs->ccw)
					std::swap(t.vertices[1], t.vertices[2]);

				triangles.push_back(t);

				triVerts[1] = vpos;
			}
		}
	}
}

int getIndex(const IntVec &coordIndex, const IntVec &vec, bool perVertex, int facenr, int index)
{
	if (!perVertex) {
		if (!vec.empty())
			return vec[facenr];
		else
			return facenr;
	} else {
		if (!vec.empty())
			return vec[index];
		else
			return coordIndex[index];
	}
}

const String *findName(const vrmllib::node *n)
{
	NameMap::const_iterator i = gNameMap.find(n);
	if (i == gNameMap.end())
		return 0;
	else
		return &i->second;
}

const String *findNameRecursive(const vrmllib::node *n)
{
	if (const String *name = findName(n))
		return name;
	else if (n->parent)
		return findNameRecursive(n->parent);
	else
		return 0;
}

void parseFaces(FaceVec &faces, const IndexedFaceSet *ifs)
{
	face f;
	for (IntVec::const_iterator i=ifs->coordIndex.begin(), e=ifs->coordIndex.end(); i!=e; ++i) {
		if (*i == -1) {
			faces.resize(faces.size()+1);
			faces.back().indices.swap(f.indices);
		} else
			f.indices.push_back(i - ifs->coordIndex.begin());
	}
	if (!f.indices.empty()) {
		faces.resize(faces.size()+1);
		faces.back().indices.swap(f.indices);
	}
}

Ogre::Material *parseMaterial(const Appearance *app, const String &name)
{
	vrmllib::Material *vm = app ? dynamic_cast<vrmllib::Material *>(app->material) : 0;
	vrmllib::ImageTexture *texture = app ? dynamic_cast<vrmllib::ImageTexture *>(app->texture) : 0;

	Ogre::Material *m = MaterialManager::getSingleton().createDeferred(name);

	ColourValue diffuse = texture ? ColourValue::White : col(vm->diffuseColor);
		// diffuse colour is unused by VRML when a texture is avaliable,
		// set to white to give the same effect in OGRE

	ColourValue a = diffuse;
	a.r *= vm->ambientIntensity;
	a.g *= vm->ambientIntensity;
	a.b *= vm->ambientIntensity;
	m->setAmbient(a);
	m->setDiffuse(diffuse);
	m->setSelfIllumination(col(vm->emissiveColor));
	m->setShininess(vm->shininess);
	m->setSpecular(col(vm->specularColor));

	m->setLightingEnabled(app);

	if (texture && !texture->url.empty()) {
		String texName = texture->url.front();
		size_t p = texName.find_last_of("/\\");
		if (p != texName.npos) {
			LogManager::getSingleton().logMessage("Stripping path from texture " + texName);
			texName.erase(0, p+1);
		}

		LogManager::getSingleton().logMessage("Adding texture layer for " + texName);

		Ogre::TextureUnitState *l = m->addTextureLayer(texName);
		l->setTextureAddressingMode(texture->repeatS ?
			Ogre::TextureUnitState::TAM_WRAP : Ogre::TextureUnitState::TAM_CLAMP);
	}

	return m;
}

Matrix4 transMat(vrmllib::vec3 v, bool inverse)
{
	if (inverse)
		return Matrix4::getTrans(-v.x, -v.y, -v.z);
	else
		return Matrix4::getTrans(v.x, v.y, v.z);
}

Matrix4 scaleMat(vrmllib::vec3 v, bool inverse)
{
	if (inverse)
		return Matrix4::getScale(1/v.x, 1/v.y, 1/v.z);
	else
		return Matrix4::getScale(v.x, v.y, v.z);
}

Matrix4 rotMat(vrmllib::rot r, bool inverse)
{
	Matrix3 rot3;
	rot3.FromAxisAngle(vec(r.vector), inverse ? -r.radians : r.radians);
	Matrix4 rot = Matrix4::IDENTITY;
	rot = rot3;
	return rot;
}