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

Rendering of single scattering using types of light sources : review

In spite of their diverse applications, realistic rendering of light scattering In participating media is still very challenging due to the complexity of the variety radiative transport processes. In this study, we address several types of light models that play important role in realistic images synthesis and determine the advantages and shortcomings of each of them. Our study focus is on the interaction between the light models with particles in the air such as dust, fog, mist, haze, smoke, etc. We seek to provide information to help the reader to select the optimal and suitable light model with numerous of applications in computer graphics

Soft bilateral filtering volumetric shadows using cube shadow maps

<div><p>Volumetric shadows often increase the realism of rendered scenes in computer graphics. Typical volumetric shadows techniques do not provide a smooth transition effect in real-time with conservation on crispness of boundaries. This research presents a new technique for generating high quality volumetric shadows by sampling and interpolation. Contrary to conventional ray marching method, which requires extensive time, this proposed technique adopts downsampling in calculating ray marching. Furthermore, light scattering is computed in High Dynamic Range buffer to generate tone mapping. The bilateral interpolation is used along a view rays to smooth transition of volumetric shadows with respect to preserving-edges. In addition, this technique applied a cube shadow map to create multiple shadows. The contribution of this technique isreducing the number of sample points in evaluating light scattering and then introducing bilateral interpolation to improve volumetric shadows. This contribution is done by removing the inherent deficiencies significantly in shadow maps. This technique allows obtaining soft marvelous volumetric shadows, having a good performance and high quality, which show its potential for interactive applications.</p></div

The two different scenes of the Elephant model, (left) rendering the scene using 200 step for each sample without bilateral filtering by ray marching, (right) rendering the scene using 60 steps for each sample with bilateral filtering.

<p>The two different scenes of the Elephant model, (left) rendering the scene using 200 step for each sample without bilateral filtering by ray marching, (right) rendering the scene using 60 steps for each sample with bilateral filtering.</p

Bunny and Fence models on shadows: Right side: the effect of Fence model; Left side: the effect of Bunny and Fence together, bottom the effect of bunny on shading the scene.

<p>Bunny and Fence models on shadows: Right side: the effect of Fence model; Left side: the effect of Bunny and Fence together, bottom the effect of bunny on shading the scene.</p

The parameters of bilateral filter on a height field.

<p>The parameters of bilateral filter on a height field.</p

Procedure of vertex shader and fragment shader for input of main program (SoftBiF-VS).

<p>Procedure of vertex shader and fragment shader for input of main program (SoftBiF-VS).</p

Shows effect soft volumetric shadows of our method using models in different sizes.

<p>Shows effect soft volumetric shadows of our method using models in different sizes.</p