diff --git a/geometry.cpp b/geometry.cpp
index 849948c..bee9195 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -37,10 +37,12 @@ drawvec decode_geometry(FILE *meta, std::atomic<long long> *geompos, int z, unsi
 	while (1) {
 		draw d;
 
-		if (!deserialize_byte_io(meta, &d.op, geompos)) {
+		signed char op;
+		if (!deserialize_byte_io(meta, &op, geompos)) {
 			fprintf(stderr, "Internal error: Unexpected end of file in geometry\n");
 			exit(EXIT_FAILURE);
 		}
+		d.op = op & VT_CLOSEPATH;
 		if (d.op == VT_END) {
 			break;
 		}
@@ -77,6 +79,13 @@ drawvec decode_geometry(FILE *meta, std::atomic<long long> *geompos, int z, unsi
 
 			d.x = wwx;
 			d.y = wwy;
+
+			if (op & VT_NODE_3D) {
+				deserialize_double_io(meta, &d.elevation, geompos);
+			}
+			if (op & VT_NODE_ATTRIB) {
+				deserialize_string_io(meta, d.attributes, geompos);
+			}
 		}
 
 		out.push_back(d);
diff --git a/geometry.hpp b/geometry.hpp
index c2e11df..3cb1d68 100644
--- a/geometry.hpp
+++ b/geometry.hpp
@@ -15,6 +15,9 @@
 #define VT_LINETO 2
 #define VT_CLOSEPATH 7
 
+#define VT_NODE_3D 8
+#define VT_NODE_ATTRIB 16
+
 // The bitfield is to make sizeof(draw) be 16 instead of 24
 // at the cost, apparently, of a 0.7% increase in running time
 // for packing and unpacking.
diff --git a/serial.cpp b/serial.cpp
index 6047be4..c74861d 100644
--- a/serial.cpp
+++ b/serial.cpp
@@ -30,6 +30,11 @@ size_t fwrite_check(const void *ptr, size_t size, size_t nitems, FILE *stream, c
 	return w;
 }
 
+void serialize_double(FILE *out, double n, std::atomic<long long> *fpos, const char *fname) {
+	fwrite_check(&n, sizeof(double), 1, out, fname);
+	*fpos += sizeof(double);
+}
+
 void serialize_int(FILE *out, int n, std::atomic<long long> *fpos, const char *fname) {
 	serialize_long_long(out, n, fpos, fname);
 }
@@ -72,6 +77,12 @@ void serialize_uint(FILE *out, unsigned n, std::atomic<long long> *fpos, const c
 	*fpos += sizeof(unsigned);
 }
 
+void serialize_string(FILE *out, std::string const &s, std::atomic<long long> *fpos, const char *fname) {
+	serialize_ulong_long(out, s.size(), fpos, fname);
+	fwrite_check(s.c_str(), sizeof(char), s.size(), out, fname);
+	*fpos += s.size();
+}
+
 void deserialize_int(char **f, int *n) {
 	long long ll;
 	deserialize_long_long(f, &ll);
@@ -112,6 +123,27 @@ void deserialize_byte(char **f, signed char *n) {
 	*f += sizeof(signed char);
 }
 
+int deserialize_double_io(FILE *f, double *n, std::atomic<long long> *geompos) {
+	if (fread(n, sizeof(double), 1, f) == 1) {
+		*geompos += sizeof(double);
+		return 1;
+	}
+	return 0;
+}
+
+int deserialize_string_io(FILE *f, std::string &s, std::atomic<long long> *geompos) {
+	unsigned long long len;
+	if (deserialize_ulong_long_io(f, &len, geompos)) {
+		char tmp[len];
+		if (fread(tmp, sizeof(char), len, f) == len) {
+			*geompos += len;
+			s = std::string(tmp, len);
+			return 1;
+		}
+	}
+	return 0;
+}
+
 int deserialize_long_long_io(FILE *f, long long *n, std::atomic<long long> *geompos) {
 	unsigned long long zigzag = 0;
 	int ret = deserialize_ulong_long_io(f, &zigzag, geompos);
@@ -171,9 +203,25 @@ int deserialize_byte_io(FILE *f, signed char *n, std::atomic<long long> *geompos
 static void write_geometry(drawvec const &dv, std::atomic<long long> *fpos, FILE *out, const char *fname, long long wx, long long wy) {
 	for (size_t i = 0; i < dv.size(); i++) {
 		if (dv[i].op == VT_MOVETO || dv[i].op == VT_LINETO) {
-			serialize_byte(out, dv[i].op, fpos, fname);
+			int op = dv[i].op;
+			if (!isnan(dv[i].elevation)) {
+				op |= VT_NODE_3D;
+			}
+			if (dv[i].attributes.size() != 0) {
+				op |= VT_NODE_ATTRIB;
+			}
+
+			serialize_byte(out, op, fpos, fname);
 			serialize_long_long(out, dv[i].x - wx, fpos, fname);
 			serialize_long_long(out, dv[i].y - wy, fpos, fname);
+
+			if (op & VT_NODE_3D) {
+				serialize_double(out, dv[i].elevation, fpos, fname);
+			}
+			if (op & VT_NODE_ATTRIB) {
+				serialize_string(out, dv[i].attributes, fpos, fname);
+			}
+
 			wx = dv[i].x;
 			wy = dv[i].y;
 		} else {
diff --git a/serial.hpp b/serial.hpp
index e52a6a8..233b390 100644
--- a/serial.hpp
+++ b/serial.hpp
@@ -16,21 +16,25 @@ size_t fwrite_check(const void *ptr, size_t size, size_t nitems, FILE *stream, c
 void serialize_int(FILE *out, int n, std::atomic<long long> *fpos, const char *fname);
 void serialize_long_long(FILE *out, long long n, std::atomic<long long> *fpos, const char *fname);
 void serialize_ulong_long(FILE *out, unsigned long long n, std::atomic<long long> *fpos, const char *fname);
+void serialize_double(FILE *out, double n, std::atomic<long long> *fpos, const char *fname);
 void serialize_byte(FILE *out, signed char n, std::atomic<long long> *fpos, const char *fname);
 void serialize_uint(FILE *out, unsigned n, std::atomic<long long> *fpos, const char *fname);
-void serialize_string(FILE *out, const char *s, std::atomic<long long> *fpos, const char *fname);
+void serialize_string(FILE *out, std::string const &s, std::atomic<long long> *fpos, const char *fname);
 
 void deserialize_int(char **f, int *n);
 void deserialize_long_long(char **f, long long *n);
 void deserialize_ulong_long(char **f, unsigned long long *n);
+void deserialize_double(char **f, double *n);
 void deserialize_uint(char **f, unsigned *n);
 void deserialize_byte(char **f, signed char *n);
 
 int deserialize_int_io(FILE *f, int *n, std::atomic<long long> *geompos);
 int deserialize_long_long_io(FILE *f, long long *n, std::atomic<long long> *geompos);
 int deserialize_ulong_long_io(FILE *f, unsigned long long *n, std::atomic<long long> *geompos);
+int deserialize_double_io(FILE *f, double *n, std::atomic<long long> *geompos);
 int deserialize_uint_io(FILE *f, unsigned *n, std::atomic<long long> *geompos);
 int deserialize_byte_io(FILE *f, signed char *n, std::atomic<long long> *geompos);
+int deserialize_string_io(FILE *f, std::string &s, std::atomic<long long> *geompos);
 
 struct serial_val {
 	int type = 0;