[Python] Black screen instead of rendering 3D model

I have been trying to use kivy to render a 3D model for an interactive app in a website but I am yet to achieve this. At first it was crashing and I have done a few changes to solve those issues up to this point, namely:

• Adding a missing default.glsl file which I got from github
• Adding an "empty.png" file when it crashed because this file was absent
• I changed a portion of the objloader.py from this:

if not material.map:
material.map = Image(folder + '/empty.png').texture
material.texture_ratio = 0.0
mesh = Mesh(geometry, material)
return mesh


to this:

if not material.map:
empty_path = os.path.join(folder, 'empty.png')
if os.path.exists(empty_path):
try:
img = Image(empty_path)
material.map = img.texture
except Exception as e:
Logger.warning(f"WaveObject: Could not load texture '{empty_path}': {e}")
material.map = None
else:
Logger.warning(f"WaveObject: 'empty.png' not found at '{empty_path}'")
material.map = None
material.texture_ratio = 0.0
mesh = Mesh(geometry, material)
return mesh


Now it no longer crashes but I get a black screen and only the mouse feature of right-clicking to place a red dot and left clicking to remove it works.

The following is my main file (It has some debugging code from when I was trying to get to the bottom of the issue).

import os
os.environ['KIVY_IMAGE'] = 'pil'

from kivy.core.image import Image
from kivy.app import App
from kivy.core.window import Window
from kivy.uix.widget import Widget
from kivy3 import Scene, Renderer
from kivy3.loaders import OBJLoader
from kivy3 import PerspectiveCamera

from kivy.graphics.context_instructions import Scale

class MainWidget(Widget):
def __init__(self, **kwargs):
super().__init__(**kwargs)

# Create a scene and load the 3D model
self.scene = Scene()
loader = OBJLoader()
obj = loader.load('C:/Users/chris/OneDrive/Documents/St.lucia_Cultural_Heritage_Project/assets/St_Lucia_Map_Final_2.obj')
self.scene.add(obj)

# Optional debugging: print model info
print("OBJ model loaded:", obj)
if hasattr(obj, 'pos'):
print("Model position:", obj.pos)
if hasattr(obj, 'scale'):
print("Model scale:", obj.scale)
if hasattr(obj, 'geometry'):
print(f"Geometry has {len(obj.geometry.vertices)} vertices")

obj.pos = (0,0,0)
self.scene.add(obj)

# Set up the camera
self.camera = PerspectiveCamera(75, 1, 1, 1000)
self.camera.pos = (0, 0, -10) # Adjust position as necessary
self.camera.aspect = self.width/float(self.height) if self.height != 0 else 1

print("Camera position:", self.camera.pos)
print("Camera aspect ratio:", self.camera.aspect)
# Set up the renderer
self.renderer = Renderer()
self.renderer.camera = self.camera
self.renderer.scene = self.scene

self.renderer.size = Window.size
print("Renderer size:", self.renderer.size)

self.add_widget(self.renderer)

# Print renderer and scene info
print("Renderer size:", self.renderer.size)
print("Scene children count:", len(self.scene.objects) if hasattr(self.scene, 'objects') else 'n/a')

# Ensure the renderer resizes with the window
Window.bind(on_resize=self.on_window_resize)
print("Initial setup complete")

def on_window_resize(self, window, width, height):
self.renderer.size = (width, height)
if height != 0:
self.camera.aspect = width / float(height)
else:
self.camera.aspect = 1
print(f"Window resized: size=({width}, {height}), camera aspect= {self.camera.aspect}")


class StLucia3DApp(App):
def build(self):
return MainWidget()

if __name__ == '__main__':
StLucia3DApp().run()`


Any assistance would be greatly appreciated.

I was expecting it to display a 3D model which I had made. I was hoping to then make it interactive where the user clicks on a spot of the map and it would zoom into that area and display information and other multimedia.

I was hoping that I'd then be able to integrate it into a website made with Django.

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