plot2gltf 1.0

A module for creating GLTF files with various geometric primitives and 3D text labels.

plot2gltf

A Claude-created Python module to save different types of simple geometry and annotations to glTF. You can view the result in any GLTF viewer, such as:

• The <model-viewer> tag
• Online viewers like https://gltf-viewer.donmccurdy.com/
• Three.js-based web viewers
• Blender

Key features:

1. Supports multiple geometry types:
   • Triangle meshes
   • Line segments and line strips (as hairlines or cylinder tubes)
   • Points (as dots or spheres)
   • Normal vectors (as lines or arrows)
   • Text labels
2. Automatic color generation using the golden ratio for visually distinct colors
3. Optional manual color specification
4. All geometries are combined into a single GLTF file
5. Proper material setup with metallic-roughness PBR workflow

It is meant to be as easy to use as generating a 3D matplotlib plot.

Example

# Example usage:
from plot2gltf import GLTFGeometryExporter

exporter = GLTFGeometryExporter()

# Add a triangle mesh
vertices = [
    [0, 0, 0],
    [1, 0, 0],
    [0, 1, 0]
]
faces = [[0, 1, 2]]
exporter.add_triangles(vertices, faces, color=(1, 0, 0))  # Red triangles

# Add some lines
line_vertices = [
    [0, 0, 0],
    [1, 1, 1]
]
edges = [[0, 1]]
exporter.add_lines(line_vertices, edges)  # Auto-generated color

# Create a square as a line strip
points = [
    [0,0,0],
    [1,0,0],
    [1,1,0],
    [0,1,0]
]
exporter.add_linestrip(points, color=(1,0,0))  # Creates a line strip
# The same but as cylinders with sphere mitering and endcaps
exporter.add_cylinder_strips(points, color=(1,0,0), radius=0.03, add_spheres=True)

# Add labels for some points
exporter.add_text([0, 0, 0.1], "Origin", size=0.2, color=(1, 1, 1))  # White text
exporter.add_text([1, 1, 1.1], "Point 2", size=0.3)  # Auto-colored text

# Or for a curve
t = np.linspace(0, 2*np.pi, 50)
curve_points = np.column_stack([
    np.cos(t),
    np.sin(t),
    np.zeros_like(t)
])
exporter.add_linestrip(curve_points, color=(0,1,0))  # Creates a smooth curve
# The same but as cylinders with sphere mitering and endcaps
exporter.add_cylinder_strips(curve_points, color=(0,1,0), radius=0.03, add_spheres=True)

# Add points
points = [
    [0, 0, 0],
    [1, 0, 0],
    [0, 1, 0]
]
exporter.add_points(points, color=(0, 1, 0))  # Green points
# The same but as spheres
exporter.add_spheres(points, color=(0, 1, 0))  # Green points

# Add normals
normal_points = [[0, 0, 0]]
normal_directions = [[0, 0, 1]]
exporter.add_normals(normal_points, normal_directions, color=(0, 0, 1))  # Blue normals
# The same but as cylinders with cone caps
exporter.add_normal_arrows(
            normal_points, normal_directions, color=(0, 0, 1),
            shaft_radius=0.02, head_radius=0.04
        )

# Save the file
exporter.save("output.gltf")

Installation

Copy plot2gltf.py and fonts into your python.

Install dependencies via:

pip install -r requirements.txt

Demo

There is a weird, Claude-generated comprehensive demo. Run it via:

python demo.py

The output file is named demo_scene.gltf.

This demo file showcases:

1. Geometric Primitives:

   • Triangles (cube and house)
   • Lines (coordinate axes)
   • Points (spiral pattern)
   • Normals (orientation vectors)

2. Text Features:

   • Different sizes
   • Different colors
   • Labels for geometric objects
   • Stand-alone text examples

3. Color Usage:

   • Manual color specification
   • Automatic color generation
   • Different colors for different object types

4. Complex Shapes:

   • A cube with multiple faces
   • A spiral point cloud
   • A simple house shape
   • Coordinate axes

The scene includes a variety of objects arranged in a way that makes it easy to see all the features.

License

Public Domain (CC0)

The included DejaVu font has its own (free) license.