Generalized Image Acquisition and Analysis
Eikonal Rendering: Efficient Light Transport in Refractive Objects
We present a new method for real-time rendering of sophisticated lighting effects in and around refractive objects. It enables us to realistically display refractive objects with complex material properties, such as arbitrarily varying refraction index, inhomogeneous attenuation, as well as spatially-varying anisotropic scattering and reflectance properties. User-controlled changes of lighting positions only require a few seconds of update time. Our method is based on a set of ordinary differential equations derived from the eikonal equation, the main postulate of geometric optics. This set of equations allows for fast casting of bent light rays with the complexity of a particle tracer. Based on this concept, we also propose an efficient light propagation technique using adaptive wavefront tracing. Efficient GPU implementations for our algorithmic concepts enable us to render visual effects that were previously not reproducible in this combination in real-time.
Projects
Property and Lighting Manipulations for Static Volume Stylization Using a Painting Metaphor
TVCG 2014
Abstract
Although volumetric phenomena are important for realistic
rendering and can even be a crucial component in the image,
the artistic control of the volume’s appearance is
challenging. Appropriate tools to edit volume properties are
missing, which can make it necessary to use simulation
results directly. Alternatively, high-level modifications
that are rarely intuitive, e.g., the tweaking of noise
function parameters, can be utilized.
Our work introduces a solution to stylize single-scattering
volumetric effects in static volumes. Hereby, an artistic
and intuitive control of emission, scattering and extinction
becomes possible, while ensuring a smooth and coherent
appearance when changing the viewpoint. Our method is based
on tomographic reconstruction, which we link to the
volumetric rendering equation. It analyzes a number of
target views provided by the artist and adapts the volume
properties to match the appearance for the given
perspectives. Additionally, we describe how we can optimize
for the environmental lighting to match a desired scene
appearance, while keeping volume properties
constant. Finally, both techniques can be combined. We
demonstrate several use cases of our approach and illustrate
its effectiveness.
Video Bibtex
@article{Klehm:14,
author = {Oliver Klehm and Ivo Ihrke and Hans-Peter Seidel and Elmar Eisemann},
title = {Property and Lighting Manipulations for Static Volume Stylization Using a Painting Metaphor},
journal = {Transactions of Visualization and Computer Graphics},
year = 2014,
pages = {xx--yy},
}
author = {Oliver Klehm and Ivo Ihrke and Hans-Peter Seidel and Elmar Eisemann},
title = {Property and Lighting Manipulations for Static Volume Stylization Using a Painting Metaphor},
journal = {Transactions of Visualization and Computer Graphics},
year = 2014,
pages = {xx--yy},
}