About the Influence of Illumination Models on Image Comprehension in Direct Volume Rendering

2011 ◽  
Vol 17 (12) ◽  
pp. 1922-1931 ◽  
Author(s):  
F. Lindemann ◽  
T. Ropinski
Keyword(s):  
Volume Rendering ◽  
Direct Volume Rendering ◽  
Illumination Models ◽  
Image Comprehension

scholarly journals Approximate Image-Space Multidirectional Occlusion Shading Model for Direct Volume Rendering

2021 ◽  
Vol 11 (12) ◽  
pp. 5717
Author(s):  
Yun Jang ◽  
Seokyeon Kim
Keyword(s):  
Transfer Function ◽  
Volume Rendering ◽  
Visual Cues ◽  
Global Illumination ◽  
Computational Cost ◽  
Image Space ◽  
Direct Volume Rendering ◽  
Ambient Occlusion ◽  
Wide Range ◽  
Illumination Models

Understanding and perceiving three-dimensional scientific visualizations, such as volume rendering, benefit from visual cues produced by the shading models. The conventional approaches are local shading models since they are computationally inexpensive and straightforward to implement. However, the local shading models do not always provide proper visual cues since non-local information is not sufficiently taken into account for the shading. Global illumination models achieve better visual cues, but they are often computationally expensive. It has been shown that alternative illumination models, such as ambient occlusion, multidirectional shading, and shadows, provide decent perceptual cues. Although these models improve upon local shading models, they still require expensive preprocessing, extra GPU memory, and a high computational cost, which cause a lack of interactivity during the transfer function manipulations and light position changes. In this paper, we proposed an approximate image-space multidirectional occlusion shading model for the volume rendering. Our model was computationally less expensive compared to the global illumination models and did not require preprocessing. Moreover, interactive transfer function manipulations and light position changes were achievable. Our model simulated a wide range of shading behaviors, such as ambient occlusion and soft and hard shadows, and can be effortlessly applied to existing rendering systems such as direct volume rendering. We showed that the suggested model enhanced the visual cues with modest computational costs.

Adaptive Illumination Sampling for Direct Volume Rendering

2020 ◽  
pp. 107-118
Author(s):  
Valentin Kraft ◽  
Florian Link ◽  
Andrea Schenk ◽  
Christian Schumann
Keyword(s):  
Volume Rendering ◽  
Direct Volume Rendering

A direct volume rendering visualization approach for serial PET–CT scans that preserves anatomical consistency

2019 ◽  
Vol 14 (5) ◽  
pp. 733-744
Author(s):  
Younhyun Jung ◽  
Jinman Kim ◽  
Lei Bi ◽  
Ashnil Kumar ◽  
David Dagan Feng ◽  
...  
Keyword(s):  
Volume Rendering ◽  
Ct Scans ◽  
Direct Volume Rendering ◽  
Pet Ct

Classification of neurovascular compression in typical hemifacial spasm: three-dimensional visualization of the facial and the vestibulocochlear nerves

2007 ◽  
Vol 107 (6) ◽  
pp. 1154-1163 ◽  
Author(s):  
Ramin Naraghi ◽  
Levent Tanrikulu ◽  
Regina Troescher-Weber ◽  
Barbara Bischoff ◽  
Martin Hecht ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Facial Nerve ◽  
Volume Rendering ◽  
Hemifacial Spasm ◽  
Three Dimensional ◽  
Neurosurgical Procedures ◽  
Neurovascular Compression ◽  
Direct Volume Rendering ◽  
Vestibulocochlear Nerve ◽  
Cerebellar Artery

Object In this paper, the authors introduce a method of noninvasive anatomical analysis of the facial nerve–vestibulocochlear nerve complex and the depiction of the variable vascular relationships by using 3D volume visualization. With this technique, a detailed spatial representation of the facial and vestibulocochlear nerves was obtained. Patients with hemifacial spasm (HFS) resulting from neurovascular compression (NVC) were examined. Methods A total of 25 patients (13 males and 12 females) with HFS underwent 3D visualization using magnetic resonance (MR) imaging with 3D constructive interference in a steady state (CISS). Each data set was segmented and visualized with respect to the individual neurovascular relationships by direct volume rendering. Segmentation and visualization of the facial and vestibulocochlear nerves were performed with reference to their root exit zone (REZ), as well as proximal and distal segments including corresponding blood vessels. The 3D visualizations were interactively compared with the intraoperative situation during microvascular decompression (MVD) to verify the results with the observed microneurosurgical anatomy. Results Of the 25 patients, 20 underwent MVD (80%). Microvascular details were recorded on the affected and unaffected sides. On the affected sides, the anterior inferior cerebellar artery (AICA) was the most common causative vessel. The posterior inferior cerebellar artery, vertebral artery, internal auditory artery, and veins at the REZ of the facial nerve (the seventh cranial nerve) were also found to cause vascular contacts to the REZ of the facial nerve. In addition to this, the authors identified three distinct types of NVC within the REZ of the facial nerve at the affected sides. The authors analyzed the varying courses of the vessels on the unaffected sides. There were no bilateral clinical symptoms of HFS and no bilateral vascular compression of the REZ of the facial nerve. The authors discovered that the AICA is the most common vessel that interferes with the proximal and distal portions of the facial nerve without any contact between vessels and the REZ of the facial nerve on the unaffected sides. Conclusions Three-dimensional visualization by direct volume rendering of 3D CISS MR imaging data offers the opportunity of noninvasive exploration and anatomical categorization of the facial nerve–vestibulocochlear nerve complex. Furthermore, it proves to be advantageous in establishing the diagnosis and guiding neurosurgical procedures by representing original MR imaging patient data in a 3D fashion. This modality provides an excellent overview of the entire neurovascular relationship of the cerebellopontine angle in each case.

The Evaluation of Direct Volume Rendering-Based Uncertainty Visualization Techniques for 3D Scalar Data

2014 ◽  
Vol 14 (04) ◽  
pp. 1450017
Author(s):  
Ji Ma ◽  
David Murphy ◽  
Gregory Provan ◽  
Cian O'Mathuna ◽  
Michael Hayes
Keyword(s):  
Volume Rendering ◽  
Completion Time ◽  
User Study ◽  
Task Completion ◽  
Direct Volume Rendering ◽  
Uncertainty Visualization ◽  
Task Completion Time ◽  
Scalar Data ◽  
Novel Method ◽  
Visualization Techniques

Many techniques have been proposed to represent uncertainty in data visualization. However, little research has been reported on the evaluation of their effectiveness. Moreover, no studies have been conducted to evaluate direct volume rendering (DVR)-based uncertainty visualization techniques. In this paper, we present a novel method that evaluates the perceptual effectiveness of four existing and one proposed DVR-based uncertainty visualization techniques. Four types of searching tasks that include identifying the maximum uncertainty data, identifying the minimum uncertainty data, identifying the maximum scalar data and identifying the minimum scalar data have been involved in this study, and a total of twenty-eight participants have contributed to the final main user study. Our analysis suggested that the proposed linked views and interactive specification (LVIS) technique appears to be the most accurate among all techniques, although it takes the longest task completion time. For the four existing techniques, the overlays technique appears to be the most advantageous, and it takes similar task completion time as the others. We believe that these findings can provide useful guidance for future uncertainty visualization design.

Sign in / Sign up

Export Citation Format

Share Document