Comments on: Test: CUDA Volume Raycasting http://www.rpenalva.com/blog/?p=229 Computer graphics, tech demos and another thoughts... Thu, 29 Jul 2010 09:05:14 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Jean Luck http://www.rpenalva.com/blog/?p=229&cpage=1#comment-4234 Jean Luck Sun, 16 May 2010 15:36:27 +0000 http://www.rpenalva.com/blog/?p=229#comment-4234 it's doesn't work :( i still have the same problem, i think it depend of the variable SIZE set to 4294967295. Can I resolve this kind of problem please it’s doesn’t work :(

i still have the same problem, i think it depend of the variable SIZE set to 4294967295.

Can I resolve this kind of problem please

]]> By: Ruben Penalva http://www.rpenalva.com/blog/?p=229&cpage=1#comment-4219 Ruben Penalva Sat, 15 May 2010 11:57:50 +0000 http://www.rpenalva.com/blog/?p=229#comment-4219 Hi Jean, try to set the "Working Directory" of the project to "$(OutDir)". Thanks! :) Regards, Ruben Penalva Hi Jean,
try to set the “Working Directory” of the project to “$(OutDir)”. Thanks! :)

Regards,
Ruben Penalva

]]> By: Jean Luck http://www.rpenalva.com/blog/?p=229&cpage=1#comment-4216 Jean Luck Sat, 15 May 2010 10:24:04 +0000 http://www.rpenalva.com/blog/?p=229#comment-4216 I have : -Windows Vista 32 bits -NVIDIA GeForce 9300M GS -Visual Studio 2008 i have this probelm whene i try to execute the project ( Debug Win32) : Exception non gérée à 0x760142eb dans CUDARayCasting.exe : Exception Microsoft C++ : char à l'emplacement mémoire 0x001df474.. Can you help me please I have :

-Windows Vista 32 bits
-NVIDIA GeForce 9300M GS
-Visual Studio 2008
i have this probelm whene i try to execute the project ( Debug Win32) :
Exception non gérée à 0x760142eb dans CUDARayCasting.exe : Exception Microsoft C++ : char à l’emplacement mémoire 0x001df474..

Can you help me please

]]> By: Stefan http://www.rpenalva.com/blog/?p=229&cpage=1#comment-4112 Stefan Tue, 04 May 2010 07:17:29 +0000 http://www.rpenalva.com/blog/?p=229#comment-4112 >Texture mapping (+ free filtering) and extremly >fast memory and memory caching is what will >make a GPU run very fast. Even the i7 has >nothing to compare with that. For texture mapping this statement is totally accurate since TM can be effectively implemented on SIMD machine. >Even the i7 has nothing to compare with that. Volumetric ray casting does not map well to SIMD and best CPU implementations beats badly (order of magnitude) the best GPU VR ray-caster. If you would like I may provide the links so you may compare side-by-side the best from two camps if you have a sufficient hardware and accreditation with respected research facility/university, otherwise you should wait until it becomes a main stream. >Texture mapping (+ free filtering) and extremly
>fast memory and memory caching is what will
>make a GPU run very fast. Even the i7 has
>nothing to compare with that.

For texture mapping this statement is totally accurate since TM can be effectively implemented on SIMD machine.

>Even the i7 has nothing to compare with that.

Volumetric ray casting does not map well to SIMD and best CPU implementations beats badly (order of magnitude) the best GPU VR ray-caster. If you would like I may provide the links so you may compare side-by-side the best from two camps if you have a sufficient hardware and accreditation with respected research facility/university, otherwise you should wait until it becomes a main stream.

]]> By: DrManhatten http://www.rpenalva.com/blog/?p=229&cpage=1#comment-3750 DrManhatten Tue, 06 Apr 2010 15:15:22 +0000 http://www.rpenalva.com/blog/?p=229#comment-3750 Don't believe the hype. The memory and caching for a realistic sized volume set would be terrible on a CPU unless you allign your data structures very well. Texture mapping (+ free filtering) and extremly fast memory and memory caching is what will make a GPU run very fast. Even the i7 has nothing to compare with that. Especially if you have to do trilinear filter. This is what GPU's are best at. CUDA however is a stupid choice for implementing a raycaster since it does not give you any advantages. A CPU implementation might be closer in terms of speed when it comes down to isosurface Don’t believe the hype. The memory and caching for a realistic sized volume set would be terrible on a CPU unless you allign your data structures very well.

Texture mapping (+ free filtering) and extremly fast memory and memory caching is what will make a GPU run very fast.
Even the i7 has nothing to compare with that. Especially if you have to do trilinear filter. This is what GPU’s are best at. CUDA however is a stupid choice for implementing a raycaster since it does not give you any advantages.

A CPU implementation might be closer in terms of speed when it comes down to isosurface

]]> By: stefanbanev http://www.rpenalva.com/blog/?p=229&cpage=1#comment-3334 stefanbanev Fri, 05 Mar 2010 20:19:19 +0000 http://www.rpenalva.com/blog/?p=229#comment-3334 > experience with ct reconstruction and volume rendering? a lot with vr; I'm not in liberty to share it though... good luck with your experiments with vr/cuda --sb > experience with ct reconstruction and volume rendering?

a lot with vr; I’m not in liberty to share it though…

good luck with your experiments with vr/cuda

–sb

]]> By: Ruben Penalva http://www.rpenalva.com/blog/?p=229&cpage=1#comment-3332 Ruben Penalva Fri, 05 Mar 2010 18:53:29 +0000 http://www.rpenalva.com/blog/?p=229#comment-3332 Hi Stefan, thanks for posting your comment, I really appreciate it. This implementation is just a test not focus on speed but on using CUDA with something I'm familiar. You can expect really poor times. In the future I will give a try to a pure cpu ray casting algorithm(multithreading + simd). Do you have experience with ct reconstruction and volume rendering? Regards, Ruben Penalva Hi Stefan,
thanks for posting your comment, I really appreciate it.

This implementation is just a test not focus on speed but on using CUDA with something I’m familiar. You can expect really poor times. In the future I will give a try to a pure cpu ray casting algorithm(multithreading + simd).

Do you have experience with ct reconstruction and volume rendering?

Regards,
Ruben Penalva

]]> By: stefanbanev http://www.rpenalva.com/blog/?p=229&cpage=1#comment-3331 stefanbanev Fri, 05 Mar 2010 17:27:17 +0000 http://www.rpenalva.com/blog/?p=229#comment-3331 Thanks for shearing the capabilities of CUDA for volume-ray-casting, it is quite revealing. You may get an incomparably better performance form CPU based volumetric ray caster on "i7 CPU 920", however it is a good task to learn CUDA limitations. The texture mapping of small dynamically prefetched 3D texture bricks with adaptive sampling density per brick is more suitable for CUDA. Anyway good luck... Thanks for shearing the capabilities of CUDA for volume-ray-casting, it is quite revealing. You may get an incomparably better performance form CPU based volumetric ray caster on “i7 CPU 920″, however it is a good task to learn CUDA limitations. The texture mapping of small dynamically prefetched 3D texture bricks with adaptive sampling density per brick is more suitable for CUDA. Anyway good luck…

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