Expressive Single Scattering for Light Shaft Stylization

Abstract

Light scattering in participating media is a natural phenomenon that is increasingly featured in movies and games, as it is visually pleasing and lends realism to a scene. In art, it may further be used to express a certain mood or emphasize objects. Here, artists often rely on stylization when creating scattering effects, not only because of the complexity of physically correct scattering, but also to increase expressiveness. Little research, however, focuses on artistically influencing the simulation of the scattering process in a virtual 3D scene. We propose novel stylization techniques, enabling artists to change the appearance of single scattering effects such as light shafts. Users can add, remove, or enhance light shafts using occluder manipulation. The colors of the light shafts can be stylized and animated using easily modifiable transfer functions. Alternatively, our system can optimize a light map given a simple user input for a number of desired views in the 3D world. Finally, we enable artists to control the heterogeneity of the underlying medium. Our stylized scattering solution is easy to use and compatible with standard rendering pipelines. It works for animated scenes and can be executed in real time to provide the artist with quick feedback.

ReLiShaft: realistic real-time light shaft generation taking sky illumination into account

“…Down: real-time rendering using realistic light shafts with effects of sky illumination Fig. 11 A comparison between the latest sky colour generation techniques [25,58] and our results in sky colour generation which are the best benchmark for the current work as advocated by most researchers [14,32,33,48,55].…”

“…In the case of sky colour simulation in real-time rendering, our method can be compared with the latest method on outdoor rendering for light shaft generation [6,58] and [25]. Figure 11a is the result of Yusov [58] and (B) shows sunrise creation using several transfer functions by Kol et al [25] using linear interpolation with five user defined points in a time domain which extends colour modifications of light shafts. (C) is the result of our method to simulate the sky colour.…”

“…F represents epipolar sampling with single scattering [15]. G is another latest work in light shaft generation using single [25], the user changes the colours using a transfer function while in our work, the colour of the light shaft is adjusted using the effect of realtime generated sky colour. H and I are results of ReLiShaft in different situations.…”

“…Table 1 elucidates a quantitative comparison between the latest state-of-the-art in Fig. 12 A comparison between realistic light shaft, a and b: real light shaft, c: [1], d [31], e: [58], f: Epipolar sampling with single scattering [15], g: [25], h and i: Our method (ReLiShaft) light shaft generation and ReLiShaft. As can be observed, realTiSoftLS [1], Unified Volumes [31] and Volumetric Shadows [3] have the highest FPS when the number of triangles is not so high.…”

“…Kol et al [25] presented a stylization technique for generating light shafts to be used by artists. In this application, artists are able change the appearance of light scattering-focusing on light shafts-by manipulating the occluder.…”