Implement loading snapshot from stream

include/neural-graphics-primitives/testbed.h

@@ -359,6 +359,7 @@ class Testbed {
 	);
 	void visualize_nerf_cameras(ImDrawList* list, const mat4& world2proj);
 	fs::path find_network_config(const fs::path& network_config_path);
+	nlohmann::json load_network_config(std::istream& stream, bool is_compressed);
 	nlohmann::json load_network_config(const fs::path& network_config_path);
 	void reload_network_from_file(const fs::path& path = "");
 	void reload_network_from_json(const nlohmann::json& json, const std::string& config_base_path=""); // config_base_path is needed so that if the passed in json uses the 'parent' feature, we know where to look... be sure to use a filename, or if a directory, end with a trailing slash
@@ -484,7 +485,9 @@ class Testbed {
 	vec2 fov_xy() const ;
 	void set_fov_xy(const vec2& val);
 	void save_snapshot(const fs::path& path, bool include_optimizer_state, bool compress);
+	void load_snapshot(nlohmann::json config);
 	void load_snapshot(const fs::path& path);
+	void load_snapshot(std::istream& stream, bool is_compressed = true);
 	CameraKeyframe copy_camera_to_keyframe() const;
 	void set_camera_from_keyframe(const CameraKeyframe& k);
 	void set_camera_from_time(float t);

src/main.cu

@@ -159,7 +159,7 @@ int main_func(const std::vector<std::string>& arguments) {
 	}
 
 	if (snapshot_flag) {
-		testbed.load_snapshot(get(snapshot_flag));
+		testbed.load_snapshot(static_cast<fs::path>(get(snapshot_flag)));
 	} else if (network_config_flag) {
 		testbed.reload_network_from_file(get(network_config_flag));
 	}

src/python_api.cu

@@ -443,7 +443,7 @@ PYBIND11_MODULE(pyngp, m) {
 		.def("n_params", &Testbed::n_params, "Number of trainable parameters")
 		.def("n_encoding_params", &Testbed::n_encoding_params, "Number of trainable parameters in the encoding")
 		.def("save_snapshot", &Testbed::save_snapshot, py::arg("path"), py::arg("include_optimizer_state")=false, py::arg("compress")=true, "Save a snapshot of the currently trained model. Optionally compressed (only when saving '.ingp' files).")
-		.def("load_snapshot", &Testbed::load_snapshot, py::arg("path"), "Load a previously saved snapshot")
+		.def("load_snapshot", py::overload_cast<const fs::path&>(&Testbed::load_snapshot), py::arg("path"), "Load a previously saved snapshot")
 		.def("load_camera_path", &Testbed::load_camera_path, py::arg("path"), "Load a camera path")
 		.def("load_file", &Testbed::load_file, py::arg("path"), "Load a file and automatically determine how to handle it. Can be a snapshot, dataset, network config, or camera path.")
 		.def_property("loop_animation", &Testbed::loop_animation, &Testbed::set_loop_animation)

src/testbed.cu

@@ -233,6 +233,14 @@ fs::path Testbed::find_network_config(const fs::path& network_config_path) {
 	return network_config_path;
 }
 
+json Testbed::load_network_config(std::istream& stream, bool is_compressed) {
+	if (is_compressed) {
+		zstr::istream zstream{stream};
+		return json::from_msgpack(zstream);
+	}
+	return json::from_msgpack(stream);
+}
+
 json Testbed::load_network_config(const fs::path& network_config_path) {
 	bool is_snapshot = equals_case_insensitive(network_config_path.extension(), "msgpack") || equals_case_insensitive(network_config_path.extension(), "ingp");
 	if (network_config_path.empty() || !network_config_path.exists()) {
@@ -1543,7 +1551,7 @@ void Testbed::imgui() {
 		ImGui::SameLine();
 		if (ImGui::Button("Load")) {
 			try {
-				load_snapshot(m_imgui.snapshot_path);
+				load_snapshot(static_cast<fs::path>(m_imgui.snapshot_path));
 			} catch (const std::exception& e) {
 				imgui_error_string = fmt::format("Failed to load snapshot: {}", e.what());
 				ImGui::OpenPopup("Error");
@@ -2339,14 +2347,14 @@ void Testbed::SecondWindow::draw(GLuint texture) {
 }
 
 void Testbed::init_opengl_shaders() {
-	static const char* shader_vert = R"(#version 140
+	static const char* shader_vert = R"glsl(#version 140
 		out vec2 UVs;
 		void main() {
 			UVs = vec2((gl_VertexID << 1) & 2, gl_VertexID & 2);
 			gl_Position = vec4(UVs * 2.0 - 1.0, 0.0, 1.0);
-		})";
+		})glsl";
 
-	static const char* shader_frag = R"(#version 140
+	static const char* shader_frag = R"glsl(#version 140
 		in vec2 UVs;
 		out vec4 frag_color;
 		uniform sampler2D rgba_texture;
@@ -2386,7 +2394,7 @@ void Testbed::init_opengl_shaders() {
 			//Uncomment the following line of code to visualize debug the depth buffer for debugging.
 			// frag_color = vec4(vec3(texture(depth_texture, tex_coords.xy).r), 1.0);
 			gl_FragDepth = texture(depth_texture, tex_coords.xy).r;
-		})";
+		})glsl";
 
 	GLuint vert = glCreateShader(GL_VERTEX_SHADER);
 	glShaderSource(vert, 1, &shader_vert, NULL);
@@ -4746,12 +4754,7 @@ void Testbed::save_snapshot(const fs::path& path, bool include_optimizer_state,
 	tlog::success() << "Saved snapshot '" << path.str() << "'";
 }
 
-void Testbed::load_snapshot(const fs::path& path) {
-	auto config = load_network_config(path);
-	if (!config.contains("snapshot")) {
-		throw std::runtime_error{fmt::format("File '{}' does not contain a snapshot.", path.str())};
-	}
-
+void Testbed::load_snapshot(nlohmann::json config) {
 	const auto& snapshot = config["snapshot"];
 	if (snapshot.value("version", 0) < SNAPSHOT_FORMAT_VERSION) {
 		throw std::runtime_error{"Snapshot uses an old format and can not be loaded."};
@@ -4841,7 +4844,6 @@ void Testbed::load_snapshot(const fs::path& path) {
 	m_render_aabb = snapshot.value("render_aabb", m_render_aabb);
 	if (snapshot.contains("up_dir")) from_json(snapshot.at("up_dir"), m_up_dir);
 
-	m_network_config_path = path;
 	m_network_config = std::move(config);
 
 	reset_network(false);
@@ -4868,6 +4870,29 @@ void Testbed::load_snapshot(const fs::path& path) {
 	set_all_devices_dirty();
 }
 
+void Testbed::load_snapshot(const fs::path& path) {
+	auto config = load_network_config(path);
+	if (!config.contains("snapshot")) {
+		throw std::runtime_error{fmt::format("File '{}' does not contain a snapshot.", path.str())};
+	}
+
+	load_snapshot(std::move(config));
+
+	m_network_config_path = path;
+}
+
+void Testbed::load_snapshot(std::istream& stream, bool is_compressed) {
+	auto config = load_network_config(stream, is_compressed);
+	if (!config.contains("snapshot")) {
+		throw std::runtime_error{"Given stream does not contain a snapshot."};
+	}
+
+	load_snapshot(std::move(config));
+
+	// Network config path is unknown.
+	m_network_config_path = "";
+}
+
 Testbed::CudaDevice::CudaDevice(int id, bool is_primary) : m_id{id}, m_is_primary{is_primary} {
 	auto guard = device_guard();
 	m_stream = std::make_unique<StreamAndEvent>();