In the world of 3D graphics and models, the gltf file format is increasingly valued. It is designed to efficiently transmit and load 3D models, especially in real-time rendering applications such as gaming and virtual reality. To parse gltf files and take advantage of their contents, Python and C++ are two very powerful tools. Next, let’s talk about how to combine these two languages to implement the parsing of gltf files.
What is a gltf file
gltf, full name is GL Transmission Format, is an open 3D file format optimized for network transmission. This format can be said to be the "JPEG" of 3D models, because its design goal is to describe 3D scenes and models as efficiently as possible. Gltf file not only supports static models, but also contains information such as animation, materials, lighting, etc., which is suitable for various application scenarios, from web pages to mobile devices, and even high-performance game engines.
Reasons for choosing a language
In this project, the combination of Python and C++ is a good choice. Python is widely popular for its concise syntax and rich libraries, especially when it comes to handling data and file parsing. C++ is known for its high performance and control of underlying operations, and is suitable for occasions where efficient rendering and processing are required. By using Python for high-level file parsing and then calling C++ to process key performance parts, we can give full play to the advantages of both.
Install the necessary libraries
Before you begin, make sure you have a Python and C++ development environment installed. For Python, we need to install some libraries, which can be installed using the pip command:
pip install numpy pip install pygltflib
pygltflib is a Python library for processing gltf files, which can simplify the reading and parsing of files. For C++, you may need to install the GLM library, which is a library for graph math, suitable for handling vectors and matrices in 3D graphics.
Steps to parse gltf file
Let's learn step by step how to parse gltf files. First, use Python to read the basic contents of gltf files.
1. Read gltf file
Use the pygltflib library to read gltf files very conveniently. Here is a simple code snippet showing how to load a gltf file:
from pygltflib import GLTF2
def load_gltf(file_path):
gltf = GLTF2().load(file_path)
return gltf
In this function, we load the gltf file with the specified path through GLTF2().load(file_path). This operation parses the file and stores its contents in a gltf object.
2. Extract key information
After parsing the gltf file, we need to extract some useful information, such as grids, materials and textures. Here is a simple example showing how to extract grid information:
gltf = load_gltf('')
for mesh in :
print(f'Mesh name: {}')
for primitive in :
print(f'Primitive mode: {}')
Here we iterate through all the grids in the gltf file and print out their names and basic original patterns.
3. Pass data to C++
The data extracted in Python can be passed to C++ in a variety of ways. A common way is to use files or call them through the API. Here we consider using JSON format, saving the extracted data as a JSON file, and then reading it in C++.
import json
def save_mesh_data(mesh_data, output_file):
with open(output_file, 'w') as f:
(mesh_data, f)
This function will receive a dictionary containing the grid data and save it as a JSON file. Next, we read this JSON file in C++.
4. Read JSON data in C++
In C++, we can use the nlohmann/json library to process JSON data. Make sure to include this library in your C++ project. Here is a code example for reading a JSON file:
#include <iostream>
#include <fstream>
#include <nlohmann/>
using json = nlohmann::json;
void load_mesh_data(const std::string& filename) {
std::ifstream file(filename);
json j;
file >> j;
for (const auto& mesh : j) {
std::cout << "Mesh name: " << mesh["name"] << std::endl;
}
}
This function reads grid data from the specified JSON file and prints out the name of each grid.
5. Rendering 3D models
Next, we need to render the grid data to the screen. C++ performs excellently in graphics rendering and usually uses OpenGL or other graphics libraries. Based on the extracted mesh data, the corresponding OpenGL buffer can be created and the vertex, normal and texture coordinates can be uploaded to the GPU.
In this example, we assume that there is already an OpenGL context and that we are able to create shaders and render loops. Here is a simple rendering code example:
void render_mesh(const Mesh& mesh) {
// Bind VAO, draw grids, etc. glBindVertexArray();
glDrawElements(GL_TRIANGLES, , GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
}
In the rendering function, we will bind the vertex array object (VAO) and draw the mesh.
By combining Python and C++, we can efficiently parse gltf files and render 3D models. This method not only allows us to enjoy the convenience of Python, but also makes full use of the performance advantages of C++. Whether it is game development or other 3D applications, mastering this technique can help you better handle 3D content! I hope this process can bring you some inspiration and explore the deeper 3D graphics world!
This is the end of this article about the detailed explanation of the examples of parsing gltf files using Python and C++. For more related Python C++ parsing gltf content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!