Hyper-Realist Rendering: A Theoretical Framework

TL;DR

The paper proposes a theoretical framework for Hyper-Realist Rendering that leverages representational-art principles to produce perceptually convincing realism with simplified geometries and materials. It decomposes rendering into Illumination and Shading, allows non-Riemannian geometries and anamorphic proxies, and employs screen-space, artistically driven shading (notably barycentric shading) to achieve painterly realism. By formalizing these methods and emphasizing global illumination effects such as reflections, refractions, and caustics, the work aims to enable fast, real-time emulations and augmentations suitable for AR/VR and visualization. The approach offers a conceptual and methodological toolkit that can be validated through user studies and perceptual experiments, with potential applications in medical visualization, historical-site AR, and dynamic figurative paintings.

Abstract

This is the first paper in a series on hyper-realist rendering. In this paper, we introduce the concept of hyper-realist rendering and present a theoretical framework to obtain hyper-realist images. We are using the term Hyper-realism as an umbrella word that captures all types of visual artifacts that can evoke an impression of reality. The hyper-realist artifacts are visual representations that are not necessarily created by following logical and physical principles and can still be perceived as representations of reality. This idea stems from the principles of representational arts, which attain visually acceptable renderings of scenes without implementing strict physical laws of optics and materials. The objective of this work is to demonstrate that it is possible to obtain visually acceptable illusions of reality by employing such artistic approaches. With representational art methods, we can even obtain an alternate illusion of reality that looks more real even when it is not real. This paper demonstrates that it is common to create illusions of reality in visual arts with examples of paintings by representational artists. We propose an approach to obtain expressive local and global illuminations to obtain these stylistic illusions with a set of well-defined and formal methods.

Figures (12)

• Figure 1: An example of hyper-realistic emulation: An animated still life painting with dynamically changing shadows, specular highlights, and caustics using a moving area light source that emulates a painting shown in Figure \ref{['fig_stillLifeOriginal']}. The goal of such emulations is to provide direct artistic control for obtaining the desired look and feel.
• Figure 2: A hyper-realistic augmentation example that demonstrates demonstrates how global illumination improves overall quality. In this particular case, the shadow and reflection of the rolling pin are added in \ref{['fig_GaryBruinsc']}. Reflection, in particular, becomes increasingly important during motion, such as moving the camera or object positions in AR applications. The augmented image in \ref{['fig_GaryBruinsc']} was created by Gary Bruins in a computer animation / digital compositing course in 2001 taught by Ergun Akleman.
• Figure 3: To create shadow and reflection in the composited images shown in Figure \ref{['fig_GaryBruins']}, there is a need to reconstruct the proxy shapes of the countertop \ref{['fig_GaryBruins2a']} and the lid \ref{['fig_GaryBruins2b']}; and the positions and light intensities \ref{['fig_GaryBruins2c']}.
• Figure 4: This figure shows how anamorphism can be used to create illusion of impossible objects. It is important to note that there exist infinitely many solutions that can produce the same impossible object Elber2011.
• Figure 5: Anamorphism is obtained by simply projecting a 3D-looking image of an object or scene from a vantage point to a random 3D geometry. Viewing the projected image from the same vantage point creates the illusion of a 3D object or scene.