Realistic Rendering
research people publications

Real-time Rendering of Dynamic Objects in Dynamic, Low-frequency Lighting Environmnets

Ruifeng Xu

abstract:

This paper presents a pre-computation based method for real time global illumination of dynamic objects. Each frame of animation is rendered using spherical harmonics lighting basis functions. The pre-computed radiance transfer (PRT) associated with each object’s surface is unfolded to a rectangular light map. A sequence of light maps is compressed using a high dynamic range video compression technique, and uncompressed for real-time rendering. During rendering, we fetch the light map corresponding to each frame, and compose a light map corresponding to any arbitrary, low-frequency lighting condition. The computed surface light map can be applied to the object using the texture mapping facility of a graphics pipeline. The primary contribution of this paper lies in its pre-computation based real time global illumination rendering of dynamic objects. Spherical harmonics light maps (SHLM) are used to represent the pre-computation results, and the animation can be viewed from arbitrary viewpoints and in arbitrary low-frequency environment lighting in real time. The consequence is an algorithm that is capable of high quality rendering of animated characters in real-time.

publication:

This work was partially sponsored by ATI Research, I-4 Matching fund and Office of Naval Research.

Non-Iterative, Robust Monte Carlo Noise Reduction

Ruifeng Xu

abstract:

A novel Monte Carlo noise reduction operator is proposed in this paper. We apply and extend the standard bilateral filtering method and build a new local adaptive noise reduction kernel. It first computes an initial estimate for the value of each pixel, and then applies bilateral filtering using this initial estimate in its range filter kernel. It is simple both in formulation and implementation. The new operator is robust and fast in the sense that it can suppress the outliers, as well as the inter-pixel incoherence in a non-iterative way. It can be easily integrated into existing rendering systems as a post-processing step. The results of our approach are compared with those of other methods. A GPU implementation of our algorithm runs in 500ms for a 512x512 image.

publication:

This work was partially sponsored by ATI Research, I-4 Matching fund and Office of Naval Research.


university of central florida : graphics group