I’m having trouble displaying the 3D model. I’ve added light sources, but the model still appears dark on the underside. Is there a way to fix it? I suspect it might be due to the viewport, similar to how it appears in Blender (Image 1).
What lightsources are you using? It’s hard to say what’s going on without proper example of your case.
But in a case you have hemispheric light try setting groundColor to white (or lighter shade of gray)
light.groundColor = new Color3(1,1,1);