205: Offscreen rendering

This script demonstrates how to render 3D models into images without using a viewer. The model is rendered offscreen and saved as PNG images. The script includes steps for changing the camera position to get different views.

Input file name: /Users/lnan/Documents/Projects/Easy3D/resources/data/bunny.ply
image saved to /Users/lnan/Documents/Projects/Easy3D/resources/data/bunny.ply_1.png
image saved to /Users/lnan/Documents/Projects/Easy3D/resources/data/bunny.ply_2.png

# -------------------------------------------------------------------------------
# Adding Easy3D Python Bindings to the System Path
# -------------------------------------------------------------------------------
# This is required if the bindings are not installed via `pip` but are located in
# a local build directory. For building and installing Python bindings of Easy3D,
# please refer to: https://github.com/LiangliangNan/Easy3D/blob/main/README.md
# -------------------------------------------------------------------------------
import sys
sys.path.append("../../cmake-build-release/lib/python")  # Update this path to point to your Easy3D build directory.

# -------------------------------------------------------------------------------
# Importing Necessary Libraries
# -------------------------------------------------------------------------------
import easy3d  # Easy3D library for 3D visualization and processing

# -------------------------------------------------------------------------------
# Initializing Easy3D
# -------------------------------------------------------------------------------
# The `easy3d.initialize(False)` function initializes the Easy3D library.
# Use `True` to enable detailed logging, which is useful for debugging.
easy3d.initialize(False)

# -------------------------------------------------------------------------------
# Setting Up the Model and Renderer
# -------------------------------------------------------------------------------
# Define the input model file. In this case, a 3D model of a bunny in .ply format.
file_name = easy3d.resource_directory() + "/data/bunny.ply"
print(f"Input file name: {file_name}")

# Create an offscreen renderer instance. This allows rendering without a viewer.
renderer = easy3d.OffScreen()

# Add the model to the renderer.
model = renderer.add_model(file_name)

# Render the model to a PNG file.
image_file = file_name + "_1.png"
renderer.render(image_file)
print("image saved to " + image_file)

# -------------------------------------------------------------------------------
# Modifying Camera Position
# -------------------------------------------------------------------------------
# Get the current camera of the renderer.
camera = renderer.camera()

# Move the camera position slightly by adding a small offset.
# This gives a different view of the model.
pos = camera.position() + easy3d.vec3(0.2, 0.2, 0.2)

# Set the new camera position.
camera.setPosition(pos)

# Render the model again with the new camera position.
image_file = file_name + "_2.png"
renderer.render(image_file)
print("image saved to " + image_file)