A Review on Light Shafts Rendering for Indoor Scenes

Rendering light shafts is one of the important topics in computer gaming and interactive applications. The methods and models that are used to generate light shafts play crucial role to make a scene more realistic in computer graphics. This article discusses the image-based shadows and geometric-based shadows that contribute in generating volumetric shadows and light shafts, depending on ray tracing, radiosity, and ray marching technique. The main aim of this study is to provide researchers with background on a progress of light scattering methods so as to make it available for them to determine the technique best suited to their goals. It is also hoped that our classification helps researchers find solutions to the shortcomings of each method

Volumetric Fog Rendering

Käesoleva bakalaureusetöö eesmärgiks oli kirjeldada udu füüsikalist käitumist looduses ja koostada algoritm udu implementeerimiseks arvutigraafika rakendustes. Töö raames on koostatud volumeetrilist udu renderdav rakendus Unity mängumootoris. Töös hinnatakse loodud rakenduse jõudlust ning analüüsitakse tulemusi. Samuti tuuakse töös ettepanekuid volumeetrilise udu renderdamise täiustamiseks tulevikus.The aim of this bachelor’s thesis is to describe the physical behavior of fog in real life and the algorithm for implementing fog in computer graphics applications. An implementation of the volumetric fog algorithm written in the Unity game engine is also provided. The performance of the implementation is evaluated using benchmarks, including an analysis of the results. Additionally, some suggestions are made to improve the volumetric fog render-ing in the future

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

© 2018 The Author(s) Rendering atmospheric phenomena is known to have its basis in the fields of atmospheric optics and meteorology and is increasingly used in games and movies. Although many researchers have focused on generating and enhancing realistic light shafts, there is still room for improvement in terms of both qualification and quantification. In this paper, a new technique, called ReLiShaft, is presented to generate realistic light shafts for outdoor rendering. In the first step, a realistic light shaft with respect to the sun position and sky colour in any specific location, date and time is constructed in real-time. Then, Hemicube visibility-test radiosity is employed to reveal the effect of a generated sky colour on environments. Two different methods are considered for indoor and outdoor rendering, ray marching based on epipolar sampling for indoor environments, and filtering on regular epipolar of z-partitioning for outdoor environments. Shadow maps and shadow volumes are integrated to consider the computational costs. Through this technique, the light shaft colour is adjusted according to the sky colour in any specific location, date and time. The results show different light shaft colours in different times of day in real-time

Realistic real-time rendering of light shafts using blur filter: considering the effect of shadow maps

The ray marching method has become the most attractive method to provide realism in rendering the effects of light scattering in the participating media of numerous applications. This has attracted significant attention from scientific community. Up-sampling of ray marching method is suitable for rendering light shafts of realistic scenes, but suffers of consume a lot of time for rendering. Therefore, some encouraging outcomes have been achieved by using down-sampling of ray marching approach to accelerate rendered scenes. However, these methods are inherently prone to artifacts, aliasing and incorrect boundaries due to the reduced number of sample points along view rays. This research proposes a realistic real-time technique to generate soft light shafts by making use downsampling of ray marching in generating light shafts. The bilateral filtering is then applied to overcome all defects that caused by downsampling process to make a scene with smoothing transition while preserving on the edges. The contribution of this technique is to improve the boundaries of light shafts taking into account the effect of shadows. This technique allows obtaining soft marvelous light shafts, having a good performance and high quality. Thus, it is suitable for interactive applications. © 2017 Springer Science+Business Media, LL

Rendering of light shaft and shadow for indoor environments enhancing technique

The ray marching methods have become the most attractive method to provide realism in rendering the effects of light scattering in the participating media of numerous applications. This has attracted significant attention from the scientific community. Up-sampling of ray marching methods is suitable to evaluate light scattering effects such as volumetric shadows and light shafts for rendering realistic scenes, but suffers of cost a lot for rendering. Therefore, some encouraging outcomes have been achieved by using down-sampling of ray marching approach to accelerate rendered scenes. However, these methods are inherently prone to artifacts, aliasing and incorrect boundaries due to the reduced number of sample points along view rays. This study proposed a new enhancing technique to render light shafts and shadows taking into consideration the integration light shafts, volumetric shadows, and shadows for indoor environments. This research has three major phases that cover species of the effects addressed in this thesis. The first phase includes the soft volumetric shadows creation technique called Soft Bilateral Filtering Volumetric Shadows (SoftBiF-VS). The soft shadow was created using a new algorithm called Soft Bilateral Filtering Shadow (SBFS). This technique was started by developing an algorithm called Imperfect Multi-View Soft Shadows (IMVSSs) based on down-sampling multiple point lights (DMPLs) and multiple depth maps, which are processed by using bilateral filtering to obtain soft shadows. Then, down-sampling light scattering model was used with (SBFS) to create volumetric shadows, which was improved using cross-bilateral filter to get soft volumetric shadows. In the second phase, soft light shaft was generated using a new technique called Realistic Real-Time Soft Bilateral Filtering Light Shafts (realTiSoftLS). This technique computed the light shaft depending on down-sampling volumetric light model and depth test, and was interpolated by bilateral filtering to gain soft light shafts. Finally, an enhancing technique for integrating all of these effects that represent the third phase of this research was achieved. The performance of the new enhanced technique was evaluated quantitatively and qualitatively a measured using standard dataset. Results from the experiment showed that 63% of the participants gave strong positive responses to this technique of improving realism. From the quantitative evaluation, the results revealed that the technique has dramatically outpaced the stateof- the-art techniques with a speed of 74 fps in improving the performance for indoor environments

Multitouch-based collaborative pre-visualisation for computer animation

Computer animated pre-visualisation occurs at an early stage of visualising scenes in low-fidelity. This is a collaborative process, in which directors communicate with animators how shot sequences will occur. Producers also take notes to approximate costs and other stakeholders may give further input. The problem with this approach is that the improvement cycles can take a long time, making the process take exponentially longer with more iterations of improvement. Our aim is to create a system that reduces this time, while keeping every stakeholder of the animation on the same page. We have constructed a multitouch-enabled system for low-fidelity, animated 3D pre-visualisation. This tool runs on a single, large multitouch table and caters for simultaneous input from multiple users, to better support collaboration. Users can navigate the virtual environment, place and manipulate 3d objects in the scene, as well as animate them, all using multitouch. The system was constructed using the user-centred systems design (UCSD) methodology. After several iterations of development, we performed a qualitative evaluation of the _nal system using two groups, one consisting of film makers and the other consisting of software developers, and concluded with interviews to get qualitative feedback about our pre-visualisation tool. Both groups suggested that the system's setup promoted collaboration and communication, which is important early on in the planning phase of film creation. However, both groups agreed that such a tool is only useful for low-fidelity pre-visualisation, as it might become "cumbersome" to perform detailed animations using multitouch input. Furthermore, the system was often too dependent on the viewpoint, which was a single user task, effectively minimizing the amount of work that could actually be done by collaborative users simultaneously. This study highlights the potential of a multitouch, collaborative pre-visualisation tool