Virtual Dental Model Lighting Estimation for Mobile AR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for visualizing virtual teeth in dental applications fail to provide realistic rendering and illumination, leading to the 'uncanny valley' issue, especially in real-time and augmented reality applications, and are not optimized for mobile devices with limited computing power.
Innovation Solution
A computer-implemented method that estimates and applies realistic lighting to a virtual three-dimensional dental model by determining the lighting situation and shadowing in a two-dimensional image of a face, using 3D face geometry and image-based illumination, and adapts the color and shading to match the real scene, allowing for real-time rendering on mobile devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If ray tracing is used for realistic rendering, then illumination realism is improved, but processing speed deteriorates
Solution Approach 1:
The patent uses a pre-computed, simplified lighting model instead of expensive real-time ray tracing. The lighting information is captured once from the reference image and then reused for rendering the virtual teeth, sacrificing some physical accuracy for speed and efficiency.
Solution Approach 2:
The patent transforms the lighting problem from a complex physical simulation into a parameter-based approach. By extracting lighting parameters (illumination direction, intensity distribution) from the reference image and applying them directly to the virtual teeth rendering, the system achieves fast results without ray tracing.
2Measurement precision
If 3D face geometry is used for generating lighting effects, then illumination accuracy is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the essential lighting information from the reference image without requiring full 3D face geometry reconstruction. By taking out just the lighting parameters needed for rendering, the system avoids the complexity of complete 3D facial scanning and modeling.
Solution Approach 2:
Instead of using complex 3D geometry, the patent creates a simplified 2D mask of the mouth region from the reference image and uses this as a proxy for lighting calculation. This copying approach maintains sufficient accuracy while dramatically reducing system complexity.
3Manufacturing precision
If realistic lighting computation is performed, then visualization quality is improved, but computational power requirements increase
Solution Approach 1:
The patent performs lighting computation in advance by analyzing the reference image to determine lighting parameters before rendering the virtual teeth. This preliminary action allows the actual rendering to use pre-computed lighting data, reducing real-time computational requirements.
Solution Approach 2:
The patent computes lighting for the specific mouth region only, rather than for the entire face or scene. This partial action approach focuses computational resources on the critical area where virtual teeth will be rendered, reducing overall computational power requirements while maintaining visualization quality.
4Reliability
If shadowing computation based on 3D geometry is used, then rendering realism is improved, but processing time increases
Solution Approach 1:
The patent replaces complex 3D geometric shadowing calculations with a 2D image-based masking approach. By substituting the mechanical 3D geometry processing with 2D image operations, the system maintains rendering realism while significantly reducing processing time.
Solution Approach 2:
The patent uses a simple 2D mouth mask derived from the reference image instead of complex 3D geometric models for shadowing computation. This disposable, simplified representation allows fast processing while still producing realistic rendering results.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention pertains to a method for realistic visualization of a 3D virtual dental model (1) in a 2D image (20) of a face, the method comprising estimating or assuming a lighting situation in the image of the face, determining boundaries of an inner mouth region in the image, computing, based on the boundaries of the inner mouth region, on a 3D face geometry and on the lighting situation, a shadowing in the inner mouth region, computing a lighting of the dental model (1) based at least on the computed shadowing, and visualizing the dental model (1) and the 2D image (20), wherein at least the inner mouth region in the image is overlaid with a visualization (21) of the dental model having the computed lighting.