import gradio as gr
from pathlib import Path

MODEL_PATH = "./mainABC.glb"   # put main.glb next to this file

def get_model():
    # return a local path (Gradio will serve it)
    return MODEL_PATH if Path(MODEL_PATH).exists() else None

with gr.Blocks() as demo:
    gr.Markdown("## 3rd Floor — interactive viewer")
    model_view = gr.Model3D(value=None, label="3D model")
    btn = gr.Button("Load model")
    btn.click(fn=get_model, inputs=None, outputs=model_view)

demo.launch()