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** VF-Ray - Visible-Faces Driven Ray Casting **
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** README File **
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VF-Ray is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
VF-Ray is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see
<http://www.gnu.org/licenses/>.
Abstract:
Volume ray casting algorithms benefit greatly with recent increase of
GPU capabilities and power. In this paper, we present a novel memory
efficient ray casting algorithm for unstructured grids completely
implemented on GPU using a recent off-the-shelf nVidia graphics
card. Our approach is built upon a recent CPU ray casting algorithm,
called VF-Ray, that considerably reduces the memory footprint while
keeping good performance. In addition to the implementation of VF-Ray
in the graphics hardware, we also propose a restructuring in its data
structures. As a result, our algorithm is much faster than the
original software version, while using significantly less memory, it
needed only one-half of its previous memory usage. Comparing our GPU
implementation to other hardware-based ray casting algorithms, our
approach used between three to ten times less memory. These results
made it possible for our GPU implementation to handle larger datasets
on GPU than previous approaches.
Instalation:
VF-Ray code was written and tested on Linux platform using Compute
Unified Device Architecture (CUDA) Utilities from nVidia for CUDA
binding. To download and/or see more information about above
dependency see:
CUDA: http://www.nvidia.com/object/cuda_get.html
In order to proper compile the VF-Ray code, the CUDA compile
wrapper (nvcc) and libraries (cuda, cudart and cutil) should have
been installed by CUDA Toolkit and SDK from nVidia. The Makefile,
MakefileCPU and MakefileCUDA can be optionally edited to reflect
specific configurations.
Usage:
VF-Ray program is designed to run using a GPU that supports nVidia
CUDA language. It has been tested on a nVidia GeForce 8800.
Command line: ./vfRay 'volume'
VF-Ray program searches by default a directory with volume
information named: ../tet_offs/. For example, run it by calling:
$ ./vfRay spx2
and it will search for: ../tet_offs/spx2.off. Additionally, files
named spx2.tf, spx2.lmt, spx2.con and spx2.extf will also be
opened in the same directory. If they don't exist, they will be
computed and created. The only required file is the volume
itself: ../tet_offs/'volume'.off.
File Formats:
.off - Model file ( vertex position and tetrahedra ids )
.tf - Transfer Function file
.lmt - limits file ( maxEdgeLength, maxZ and minZ values )
.extf - external faces file
.con - cell connectivity file