Offset Shadow Map Sampling for Video Avatar Rendering
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Solution Overview
Problem
Conventional videoconferencing technologies lack the social interaction and immersive experience of in-person meetings, and face performance issues with large participant numbers due to bandwidth and hardware limitations, leading to slow performance and reduced realism in virtual environments.
Innovation Solution
A computer-implemented method for efficiently rendering shadows in a three-dimensional virtual environment, allowing for improved rendering of video streams onto avatars, which enhances social interaction and reduces computational load by using shadow maps and optimized rendering techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If video streams from multiple participants are rendered in a virtual environment, then social interaction and immersive experience are improved, but computational load and system performance deteriorate
Solution Approach 1:
The patent extracts the shadow rendering computation from the main video rendering pipeline by using pre-generated shadow maps. Shadow maps are created separately and stored, then used during video rendering to determine shading without requiring real-time complex shadow calculations, thereby reducing computational load while maintaining visual realism
Solution Approach 2:
Shadow maps are generated in advance before the actual video rendering process. This preliminary action allows the system to prepare shadow information beforehand, so that during video conferencing, only simple lookups and comparisons are needed, significantly reducing real-time computational requirements
2Manufacturing precision
If real-time shadow rendering is performed for each pixel, then rendering accuracy is improved, but processing speed deteriorates
Solution Approach 1:
The patent applies different rendering approaches based on local requirements: shadow maps provide accurate shadow information where needed, while offset sampling provides sufficient approximation in other areas. This localized quality approach ensures accuracy where critical while maintaining overall rendering speed
Solution Approach 2:
Instead of performing complete real-time shadow rendering for every pixel, the patent uses partial action by sampling shadow maps at offset positions. This provides sufficient shadow information for visual realism without the full computational cost of exact real-time shadow calculations for each pixel
3Measurement precision
If shadow maps are sampled at the exact pixel position, then shadow precision is improved, but shadow acne artifacts increase
Solution Approach 1:
The patent applies preliminary anti-action by intentionally offsetting the shadow map sampling position from the exact pixel position. This offset prevents the shadow acne artifacts that would occur with exact positioning, while still providing sufficiently accurate shadow information for visual realism
Solution Approach 2:
Instead of using the exact pixel position for shadow sampling, the patent creates an offset copy of the sampling position. This offset position serves as a substitute that avoids shadow acne while maintaining adequate shadow precision for the rendered image
Data Source
AI summary
Disclosed herein is a web-based videoconference system that allows for video avatars to navigate within a virtual environment. Various methods for efficient modeling, rendering, and shading are disclosed herein.