423 research outputs found
Distributed high-fidelity graphics using P2P
In the field of three-dimensional computer graphics, rendering refers to the process of generating images of a scene from a particular viewpoint. There are many different ways to do this, from the highly interactive real-time rendering methods to the more photorealistic and computationally intensive methods. This work is concerned with Physically Based Rendering (PBR), a class of rendering algorithms capable of achieving a very high level of realism. This is achievable thanks to physically accurate modelling of the way light interacts with objects in a scene, together with the use of accurately modelled materials and physical quantities.peer-reviewe
OmniLRS: A Photorealistic Simulator for Lunar Robotics
Developing algorithms for extra-terrestrial robotic exploration has always
been challenging. Along with the complexity associated with these environments,
one of the main issues remains the evaluation of said algorithms. With the
regained interest in lunar exploration, there is also a demand for quality
simulators that will enable the development of lunar robots. % In this paper,
we explain how we built a Lunar simulator based on Isaac Sim, Nvidia's robotic
simulator. In this paper, we propose Omniverse Lunar Robotic-Sim (OmniLRS) that
is a photorealistic Lunar simulator based on Nvidia's robotic simulator. This
simulation provides fast procedural environment generation, multi-robot
capabilities, along with synthetic data pipeline for machine-learning
applications. It comes with ROS1 and ROS2 bindings to control not only the
robots, but also the environments. This work also performs sim-to-real rock
instance segmentation to show the effectiveness of our simulator for
image-based perception. Trained on our synthetic data, a yolov8 model achieves
performance close to a model trained on real-world data, with 5% performance
gap. When finetuned with real data, the model achieves 14% higher average
precision than the model trained on real-world data, demonstrating our
simulator's photorealism.% to realize sim-to-real. The code is fully
open-source, accessible here: https://github.com/AntoineRichard/LunarSim, and
comes with demonstrations.Comment: 7 pages, 4 figure
Single sample soft shadows
Journal ArticleA simple extension to ray tracing is presented that creates visually plausible "soft" shadows with little extra computation. Although these soft shadows are approximate, they are robust and have penumbra widths that behave in a believable way, including accurate placement of singularities where penumbra width is zero. The method has continuous behavior in space and time, so it is appropriate for both static and dynamic image generation
Konstruksi Bounding Volume Hierarchy dengan Metode Agglomerative Clustering untuk Meningkatkan Performa Ray Tracing
Ray Tracing sebagai algoritma rendering yang menghasilkan citra realistis memiliki beberapa kekurangan. Salah satu di antaranya adalah perhitungan persilangan ray-object pada tiap pixel yang memakan 75% waktu dari keseluruhan proses rendering. Penelitian ini menerapkan metode yang diharapkan dapat mempersingkat proses perhitungan persilangan ray-object dengan membangun struktur data berupa binary tree. Tree yang dibangun sering juga disebut sebagai Bounding Volume Hierarchy (BVH) di mana masing-masing node-nya adalah sebuah container. Struktur data tersebut akan dibangun dengan metode Approximate Agglomerative Clustering (AAC) yang merupakan metode bottom-up clustering dengan top-down preprocessing. Metode AAC dengan parameter yang baik dapat meningkatkan performa Ray Tracing. Metode-metode yang diterapkan sangat mudah diparalelkan sehingga performa algoritma meningkat jika dijalankan pada lingkungan paralel. Hasil uji coba menunjukkan peningkatan kecepatan hingga 3 kali lipat dibandingkan tanpa menerapkan paralelisme. Pada hasil uji coba, juga didapatkan dua jenis parameter yang masing-masing memiliki karakteristik tersendiri (6= cepat, 12= kualitas baik)
A progressive refinement approach for the visualisation of implicit surfaces
Visualising implicit surfaces with the ray casting method is a slow procedure. The design cycle of a new implicit surface is, therefore, fraught with long latency times as a user must wait for the surface to be rendered before being able to decide what changes should be introduced in the next iteration. In this paper, we present an attempt at reducing the design cycle of an implicit surface modeler by introducing a progressive refinement rendering approach to the visualisation of implicit surfaces. This progressive refinement renderer provides a quick previewing facility. It first displays a low quality estimate of what the final rendering is going to be and, as the computation progresses, increases the quality of this estimate at a steady rate. The progressive refinement algorithm is based on the adaptive subdivision of the viewing frustrum into smaller cells. An estimate for the variation of the implicit function inside each cell is obtained with an affine arithmetic range estimation technique. Overall, we show that our progressive refinement approach not only provides the user with visual feedback as the rendering advances but is also capable of completing the image faster than a conventional implicit surface rendering algorithm based on ray casting
Progressive refinement rendering of implicit surfaces
The visualisation of implicit surfaces can be an inefficient task when such surfaces are complex and highly detailed. Visualising a surface by first converting it to a
polygon mesh may lead to an excessive polygon count. Visualising a surface by direct ray casting is often a slow procedure. In this paper we present a progressive refinement renderer for implicit surfaces that are Lipschitz continuous. The renderer first displays a low resolution estimate of what the final image is going to be and, as the computation progresses, increases the quality of this estimate at an interactive frame rate. This renderer provides a quick previewing facility that significantly reduces the design cycle of a new and complex implicit surface. The renderer is also capable of completing an image faster than a conventional implicit surface rendering algorithm based on ray casting
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Constructing the invisible - Computer graphics and the end of Optical Media
This media archaeology of early computer graphics tackles the relation between the imaginary and technical media. We focus on the algorithmic procedures and mathematical principles driving 3D computer graphics during the 1970’s and we frame them in a discussion about the end of optical media and a reflection on the current situation in which images, commanded by techno-codes, delineate and structure the dominant code of communication with which we imagine. Even though algorithmic simulations of optical worlds do not represent the end of optical media as Friedrich Kittler once argued, computer graphics can be seen retrospectively as an escalation in the production of invisibility. We introduce Frieder Nake’s concept of ‘subfaces’ to describe digital images as entities that are composed out of visible and invisible processes. The subface constitutes our methodological tool to analyze computer graphics historically, through three early problems of 3D computer graphics. We complement this media archeology of early computer graphics with discussing the dialogue between Kittler and Vilém Flusser on the imaginary or techo-imagination
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