To fix graininess in bottle 3D models, start by adjusting render settings (increase sample counts or enable anti-aliasing), upgrading texture resolution, balancing lighting, or using denoising tools.
- **Insufficient render samples**: Too few samples cause noise—boosting them smooths grainy edges on curved surfaces. - **Low-resolution textures**: Pixelated textures appear grainy—use higher-res files for crisp, clean details. - **Harsh lighting**: Sharp shadows add grain—switch to softer, diffused light to even out the bottle’s appearance.
If grain remains, enable your software’s denoiser (e.g., Blender’s OptiX or Arnold’s Denoiser) or simplify materials temporarily to pinpoint the issue.