materiały: Ray tracing (graphics)

Evidence: 100 • authority: 72

In 3D computer graphics, ray tracing is a technique for modeling light transport for use in a wide variety of rendering algorithms for generating digital images. On a spectrum of computational cost and visual fidelity, ray tracing-based rendering techniques, such as ray casting, recursive ray tracing, distribution ray tracing, photon mapping and path tracing, are generally slower and higher fidelity than scanline rendering methods. Thus, ray tracing was first deployed in applications where taking a relatively long time to render could be tolerated, such as still CGI images, and film and television visual effects (VFX), but was less suited to real-time applications such as video games, where…

Evidence: 58 • authority: 72

Ray marching is a class of rendering methods for 3D computer graphics where rays are traversed iteratively, effectively dividing each ray into smaller ray segments, sampling some function at each step. For example, in volume ray casting the function would access data points from a 3D scan. In Sphere tracing, the function estimates a distance to step next. Ray marching is also used in physics simulations as an alternative to ray tracing where analytic solutions of the trajectories of light or sound waves are solved. Ray marching for computer graphics often takes advantage of signed distance functions to determine a maximum safe step-size, while this is less common in physics simulations a si…

Evidence: 52 • authority: 72

In physics, ray tracing is a method for calculating the path of waves or particles through a system with regions of varying propagation velocity, absorption characteristics, and reflecting surfaces. Under these circumstances, wavefronts may bend, change direction, or reflect off surfaces, complicating analysis. Historically, ray tracing involved analytic solutions to the ray's trajectories. In modern applied physics and engineering physics, the term also encompasses numerical solutions to the Eikonal equation. For example, ray-marching involves repeatedly advancing idealized narrow beams called rays through the medium by discrete amounts. Simple problems can be analyzed by propagating a few…

Evidence: 47 • authority: 80

Ray Tracing: Simulating Light and Sound in Architectural Design

Evidence: 41 • authority: 72

In mathematics and physical science, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Periodic waves oscillate repeatedly about an equilibrium (resting) value at some frequency. When the entire waveform moves in one direction, it is said to be a traveling wave; by contrast, a pair of identical superimposed periodic waves traveling in opposite directions makes a standing wave. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. There are two types of waves that are most commonly studied in classical physics: mechanical waves and electromagnetic waves. In a mechanical…

Evidence: 41 • authority: 72

Beam tracing is an algorithm to simulate wave propagation. It was developed in the context of computer graphics to render 3D scenes, but it has also been used in other similar areas such as acoustics and electromagnetism simulations. Beam tracing is a derivative of the ray tracing algorithm that replaces rays, which have no thickness, with beams. Beams are shaped like unbounded pyramids, with (possibly complex) polygonal cross sections. Beam tracing was first proposed by Paul Heckbert and Pat Hanrahan. In beam tracing, a pyramidal beam is initially cast through the entire viewing frustum. This initial viewing beam is intersected with each polygon in the environment, typically from nearest t…

Evidence: 41 • authority: 92

Depth for Underwater Acoustic Detection in Deep-Sea (&gt;5000 m) Complex Marine Environments Based on the Bellhop Model.. Quantifying the detection efficiency of buoy-based sonar and optimizing deployment strategies in complex marine environments remain significant challenges. This study proposes a transceiver depth optimization method based on the Bellhop ray model to enhance underwater remote sensing data quality. For the first time, we validated the applicability of acoustic reciprocity in deep-sea environments exceeding 5000 m, characterized by non-uniform sound speed profiles, horizontal inhomogeneity, and steep seamount terrain, with a maximum relative error of <1.2%. This extends the…

Evidence: 41 • authority: 92

Sensor Placement Strategies for Target Localization via 3-D TOA Measurements in Underwater Acoustic Sensor Networks.. This article investigates sensor placement strategies for 3-D time-of-arrival (TOA)-based target localization in underwater acoustic sensor networks (UASNs). To prevent the overestimation of localization performance common in idealized marine models, we derive an exact acoustic propagation time and estimate the TOA measurement variance using a non-linear ray acoustic model. Leveraging this formulation, we establish a realistic 3-D TOA measurement model that incorporates depth-dependent sound speed profiles (SSP) and spatially heterogeneous noise, where the trace of the Cramé…

Evidence: 35 • authority: 80

Closed Form Bistatic Reverberation and Target Echoes With Variable Bathymetry and Sound Speed

Evidence: 35 • authority: 92

Phase-Consistency-Adaptive Multi-Path Total Focusing Ultrasonic Imaging for Delamination Quantification in L-Shaped CFRP Corner Parts.. The delay-and-sum total focusing method (TFM) for ultrasonic full matrix capture (FMC) depends on accurate ray path and travel time computation. In L-shaped carbon fiber-reinforced polymer (CFRP) corner parts, elastic anisotropy, multilayer stacking, and curvature-induced ray path non-uniqueness generate strong stripe-like coherent clutter (deterministic structural echoes), degrading focusing and sizing. To address this, we search multiple physically plausible candidate ray paths and propose a phase-consistency-adaptive multi-path fusion TFM (PCA-MPF-TFM) t…

Evidence: 35 • authority: 92

Robust Deep Learning for Pulse-Echo Speed of Sound Imaging via Time-Shift Maps.. Accurately imaging the spatial distribution of longitudinal speed of sound (SoS) has a profound impact on image quality and the diagnostic value of ultrasound. Knowledge of SoS distribution allows effective aberration correction to improve image quality. SoS imaging also provides a new contrast mechanism to facilitate disease diagnosis. However, SoS imaging is challenging in the pulse-echo mode. Deep learning (DL) is a promising approach for pulse-echo SoS imaging, which may yield more accurate results than pure physics-based approaches. Herein, we developed a robust DL approach for SoS imaging that learns the…

Evidence: — • authority: 72

Rendering is the process of generating an image from input data such as 3D models. The word "rendering" (in one of its senses) originally meant the task performed by an artist when depicting a real or imaginary thing (the finished artwork is also called a "rendering"). Today, to "render" commonly means to use a computer to generate an image from a precise specification, often created by an artist (or multiple artists) via interactive 3D modeling software. Types of images rendered include both still images and frames for films and video games. In a computer graphics context, in standard usage, the word "rendering" by itself means rendering 3D scenes, but it is sometimes used with a broader m…