What is the difference between opacity 3D model and Image-based 3D model?

Opacity 3D models adjust 3D element transparency (e.g., see-through glass shaders), while image-based 3D models reconstruct 3D shapes from multiple 2D images (like photogrammetry from photos). Opacity models focus on material properties to control visibility—ideal for effects like transparent liquids in bottles or layered textures showing internal details. Image-based models use 2D data (photos/scans) to replicate real-world geometry, common for realistic objects like scanned statues. For transparent effects, use opacity-adjustable models in Blender; for real-object replication from photos, try image-based workflows with Meshroom.