TriMesh: binary PLY export feature

include/mitsuba/render/trimesh.h

@@ -304,9 +304,12 @@ public:
 	static ref<TriMesh> fromBlender(const std::string &name, size_t faceCount, void *facePtr,
 		size_t vertexCount, void *vertexPtr, void *uvPtr, void *colPtr, short matNr);
 
-	/// Export an Wavefront OBJ version of this file
+	/// Export a Wavefront OBJ version of this file
 	void writeOBJ(const fs::path &path) const;
 
+	/// Export a Stanford PLY version of this file
+	void writePLY(const fs::path &path) const;
+
 	/// Return a string representation
 	std::string toString() const;
 

src/libpython/render.cpp

@@ -565,6 +565,7 @@ void export_render() {
 		.def("serialize", triMesh_serialize1)
 		.def("serialize", triMesh_serialize2)
 		.def("writeOBJ", &TriMesh::writeOBJ)
+		.def("writePLY", &TriMesh::writePLY)
 		.def("fromBlender", trimesh_fromBlender)
 		.staticmethod("fromBlender");
 

src/librender/trimesh.cpp

@@ -17,6 +17,7 @@
 */
 
 #include <mitsuba/render/trimesh.h>
+#include <mitsuba/core/version.h>
 #include <mitsuba/core/random.h>
 #include <mitsuba/core/plugin.h>
 #include <mitsuba/core/zstream.h>
@@ -84,7 +85,6 @@ TriMesh::TriMesh(Stream *stream, int index)
 	loadCompressed(stream, index);
 }
 
-
 /* Flags used to identify available data during serialization */
 enum ETriMeshFlags {
 	EHasNormals      = 0x0001,
@@ -1057,6 +1057,81 @@ void TriMesh::writeOBJ(const fs::path &path) const {
 	os.close();
 }
 
+void TriMesh::writePLY(const fs::path &path) const {
+	fs::ofstream os(path, std::ios::out | std::ios::binary);
+
+	os << "ply\n";
+	if (Stream::getHostByteOrder() == Stream::ELittleEndian)
+		os << "format binary_little_endian 1.0\n";
+	else
+		os << "format binary_big_endian 1.0\n";
+	os << "comment generated by Mitsuba " << MTS_VERSION << "\n";
+	os << "element vertex " << getVertexCount() << "\n";
+
+	size_t storagePerVertex = 3 * sizeof(float);
+	os << "property float x\n";
+	os << "property float y\n";
+	os << "property float z\n";
+
+	if (m_normals) {
+		os << "property float nx\n";
+		os << "property float ny\n";
+		os << "property float nz\n";
+		storagePerVertex += 3 * sizeof(float);
+	}
+
+	if (m_texcoords) {
+		os << "property float u\n";
+		os << "property float v\n";
+		storagePerVertex += 2 * sizeof(float);
+	}
+
+	if (m_colors) {
+		os << "property uchar red\n";
+		os << "property uchar green\n";
+		os << "property uchar blue\n";
+		storagePerVertex += 3 * sizeof(uint8_t);
+	}
+
+	os << "element face " << m_triangleCount << "\n";
+	os << "property list uchar int vertex_indices\n";
+	os << "end_header\n";
+
+	size_t vertexStorageSize = storagePerVertex * (size_t) m_vertexCount;
+	uint8_t *vertexStorage = new uint8_t[vertexStorageSize], *ptr = vertexStorage;
+
+	for (size_t i=0; i< getVertexCount(); ++i) {
+		Vector3f p(m_positions[i]); memcpy(ptr, &p, sizeof(Vector3f)); ptr += sizeof(Vector3f);
+		if (m_normals) {
+			Vector3f n(m_normals[i]); memcpy(ptr, &n, sizeof(Vector3f)); ptr += sizeof(Vector3f);
+		}
+		if (m_texcoords) {
+			Vector2f uv(m_texcoords[i]); memcpy(ptr, &uv, sizeof(Vector2f)); ptr += sizeof(Vector2f);
+		}
+		if (m_colors) {
+			*ptr += (uint8_t) std::max(0.0f, std::min(255.0f, m_colors[i][0] * 255.0f + 0.5f));
+			*ptr += (uint8_t) std::max(0.0f, std::min(255.0f, m_colors[i][1] * 255.0f + 0.5f));
+			*ptr += (uint8_t) std::max(0.0f, std::min(255.0f, m_colors[i][2] * 255.0f + 0.5f));
+		}
+	}
+	Assert(ptr-vertexStorage == vertexStorageSize);
+	os.write((const char *) vertexStorage, vertexStorageSize);
+	delete[] vertexStorage;
+
+	size_t faceStorageSize = (sizeof(Triangle) + 1) * (size_t) getTriangleCount();
+	uint8_t *faceStorage = new uint8_t[faceStorageSize];
+	ptr = faceStorage;
+	for (size_t i=0; i<getTriangleCount(); ++i) {
+		*ptr++ = (uint8_t) 0x03;
+		memcpy(ptr, &m_triangles[i], sizeof(Triangle));
+		ptr += sizeof(Triangle);
+	}
+	Assert(ptr-faceStorage == faceStorageSize);
+	os.write((const char *) faceStorage, faceStorageSize);
+	delete[] faceStorage;
+
+	os.close();
+}
 void TriMesh::serialize(Stream *_stream) const {
 	ref<Stream> stream = _stream;
 

src/shapes/ply.cpp

@@ -273,7 +273,8 @@ public:
 
 	void face_vertex_indices_begin_uint8(ply::uint8 size) {
 		if (size != 3 && size != 4)
-			Log(EError, "Only triangle and quad-based PLY meshes are supported for now.");
+			Log(EError, "Encountered a face with %i vertices! "
+				"Only triangle and quad-based PLY meshes are supported for now.", size);
 		m_indexCtr = 0;
 	}