46 research outputs found
Ray casting implicit fractal surfaces with reduced affine arithmetic
A method is presented for ray casting implicit surfaces defined by fractal combinations of procedural noise functions. The method is robust and uses affine arithmetic to bound the variation of the implicit function along a ray. The method is also efficient due to a modification in the affine arithmetic representation that introduces a condensation step at the end of every non-affine operation. We show that our method is able to retain the tight estimation capabilities of affine arithmetic for ray casting implicit surfaces made from procedural noise functions while being faster to compute and more efficient to store
Unlimited object instancing in real-time
In this paper, we propose a novel approach to efficient rendering of an unlimited number of 3D objects in real-time.
We present a rendering pipeline that is based on a new computer graphics programming paradigm implementing
a holistic approach to the virtual scene definition. Using Signed Distance Functions (SDF) for a virtual scene
representation, we managed to control the content and complexity of the virtual scene with the use of mathematical
equations. In order to solve the limited hardware problem, especially the limited capacity of the GPU memory,
we propose a scene element repository which extends the idea of the data based amplification. The content of
the repository strongly depends on a 3D object visualization method. One of the most important requirements
of the developed pipeline is the possibility to render 3D objects created by artists. In order to achieve that, the
object visualization method uses Sparse Voxel Octree (SVO) ray casting. The developed rendering pipeline is fully
compatible with the available SVO algorithms. We show how to avoid occlusion errors which can occur in the
SDF and SVO integration single-pass rendering pipeline. Finally, in order to control the content and complexity
of the virtual scenes in an unlimited way, we propose a collection of global operators applicable to the virtual
scene distance function. Developed Unlimited Object Instancing rendering pipeline can be easily integrated with
traditional visualization methods, e.g. the triangle rasterization. The only hardware requirement for our approach
is the support for compute shaders or any GPGPU API
Fast Reliable Ray-tracing of Procedurally Defined Implicit Surfaces Using Revised Affine Arithmetic
Fast and reliable rendering of implicit surfaces is an important area in the field of implicit modelling. Direct rendering, namely ray-tracing, is shown to be a suitable technique for obtaining good-quality visualisations of implicit surfaces. We present a technique for reliable ray-tracing of arbitrary procedurally defined implicit surfaces by using a modification of Affine Arithmetic called Revised Affine Arithmetic. A wide range of procedurally defined implicit objects can be rendered using this technique including polynomial surfaces, constructive solids, pseudo-random objects, procedurally defined microstructures, and others. We compare our technique with other reliable techniques based on Interval and Affine Arithmetic to show that our technique provides the fastest, while still reliable, ray-surface intersections and ray-tracing. We also suggest possible modifications for the GPU implementation of this technique for real-time rendering of relatively simple implicit models and for near real-time for complex implicit models
Interactive Rendering Framework for Distance Function Representations
Sphere tracing, introduced by Hart in [5], is an eïŹcient method to ïŹnd ray-
surface intersections, provided the surface is represented by a signed distance
function (SDF) or a lower estimate of it.
This paper presents an interactive rendering framework for visualising exact
and estimate SDF representations. We demonstrate the performance of
the system by visualising 3D fractals and its modularity by rendering algebraic
and meta surfaces. In addition, we discuss SDF estimation of algebraic
surfaces
Vector Graphics for Real-time 3D Rendering
Algorithms are presented that enable the use of vector graphics representations
of images in texture maps for 3D real time rendering.
Vector graphics images are resolution independent and
can be zoomed arbitrarily without losing detail
or crispness. Many important types of images, including text and
other symbolic information, are best represented in vector form. Vector
graphics textures can also be used as transparency mattes to augment
geometric detail in models via trim curves.
Spline curves are used to represent boundaries around regions
in standard vector graphics representations, such as PDF and SVG.
Antialiased rendering of such content can be obtained by thresholding
implicit representations of these curves.
The distance function is an especially useful implicit representation.
Accurate distance function computations would also allow the implementation
of special effects such as embossing.
Unfortunately, computing the true distance to higher order spline curves
is too expensive for real time rendering.
Therefore, normally either the distance is approximated
by normalizing some other implicit representation
or the spline curves are approximated with simpler primitives.
In this thesis, three methods for
rendering vector graphics textures in real time are introduced,
based on various approximations of the distance computation.
The first and simplest approach to the distance computation
approximates curves with line segments.
Unfortunately, approximation with line segments gives only C0 continuity.
In order to improve smoothness, spline curves can also be approximated
with circular arcs.
This approximation has C1 continuity and computing the distance
to a circular arc is only slightly more expensive than
computing the distance to a line segment.
Finally an iterative algorithm
is discussed that has good performance in practice and can compute the
distance to any parametrically differentiable curve
(including polynomial splines of any order)
robustly. This algorithm is demonstrated in the context of a system
capable of real-time rendering of SVG content in a texture map on a GPU.
Data structures and acceleration algorithms in the context of massively
parallel GPU architectures are also discussed.
These data structures and acceleration structures allow arbitrary vector
content (with space-variant complexity, and overlapping regions) to be
represented in a random-access texture
Enhancing Mesh Deformation Realism: Dynamic Mesostructure Detailing and Procedural Microstructure Synthesis
Propomos uma solução para gerar dados de mapas de relevo dinĂąmicos para simular deformaçÔes em superfĂcies macias, com foco na pele humana. A solução incorpora a simulação de rugas ao nĂvel mesoestrutural e utiliza texturas procedurais para adicionar detalhes de microestrutura estĂĄticos. Oferece flexibilidade alĂ©m da pele humana, permitindo a geração de padrĂ”es que imitam deformaçÔes em outros materiais macios, como couro, durante a animação.
As soluçÔes existentes para simular rugas e pistas de deformação frequentemente dependem de hardware especializado, que Ă© dispendioso e de difĂcil acesso. AlĂ©m disso, depender exclusivamente de dados capturados limita a direção artĂstica e dificulta a adaptação a mudanças. Em contraste, a solução proposta permite a sĂntese dinĂąmica de texturas que se adaptam Ă s deformaçÔes subjacentes da malha de forma fisicamente plausĂvel.
Vårios métodos foram explorados para sintetizar rugas diretamente na geometria, mas sofrem de limitaçÔes como auto-interseçÔes e maiores requisitos de armazenamento. A intervenção manual de artistas na criação de mapas de rugas e mapas de tensão permite controle, mas pode ser limitada em deformaçÔes complexas ou onde maior realismo seja necessårio.
O nosso trabalho destaca o potencial dos métodos procedimentais para aprimorar a geração de padrÔes de deformação dinùmica, incluindo rugas, com maior controle criativo e sem depender de dados capturados. A incorporação de padrÔes procedimentais eståticos melhora o realismo, e a abordagem pode ser estendida além da pele para outros materiais macios.We propose a solution for generating dynamic heightmap data to simulate deformations for soft surfaces, with a focus on human skin. The solution incorporates mesostructure-level wrinkles and utilizes procedural textures to add static microstructure details. It offers flexibility beyond human skin, enabling the generation of patterns mimicking deformations in other soft materials, such as leater, during animation.
Existing solutions for simulating wrinkles and deformation cues often rely on specialized hardware, which is costly and not easily accessible. Moreover, relying solely on captured data limits artistic direction and hinders adaptability to changes. In contrast, our proposed solution provides dynamic texture synthesis that adapts to underlying mesh deformations.
Various methods have been explored to synthesize wrinkles directly to the geometry, but they suffer from limitations such as self-intersections and increased storage requirements. Manual intervention by artists using wrinkle maps and tension maps provides control but may be limited to the physics-based simulations.
Our research presents the potential of procedural methods to enhance the generation of dynamic deformation patterns, including wrinkles, with greater creative control and without reliance on captured data. Incorporating static procedural patterns improves realism, and the approach can be extended to other soft-materials beyond skin