Comments for Rubén Penalva's Blog http://www.rpenalva.com/blog Computer graphics, tech demos and another thoughts... Thu, 29 Jul 2010 09:05:14 +0000 hourly 1 http://wordpress.org/?v=3.0 Comment on Test: GPU Quadratic Curve Rendering by wholesale sunglasses http://www.rpenalva.com/blog/?p=107&cpage=1#comment-6084 wholesale sunglasses Thu, 29 Jul 2010 09:05:14 +0000 http://www.rpenalva.com/blog/?p=107#comment-6084 Nice Nice

]]> Comment on Test: CUDA Volume Raycasting 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

]]> Comment on Test: CUDA Volume Raycasting 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

]]> Comment on Test: CUDA Volume Raycasting 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

]]> Comment on Test: CUDA Volume Raycasting 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.

]]> Comment on Test: CUDA Volume Raycasting 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

]]> Comment on Tech Demo: Volume Rendering of a Computed Tomography by Ruben Penalva http://www.rpenalva.com/blog/?p=5&cpage=1#comment-3684 Ruben Penalva Thu, 01 Apr 2010 20:08:39 +0000 http://www.rpenalva.com/blog/?p=5#comment-3684 Hi Binoy, thanks for sharing your thoughts. I'm thinking about make a texture based glsl volumetric rendering demo, but not now. Just in case, I published a glsl raycasting test recently with source code. Im sorry but I didnt publish the source code for this demo and Im afraid Im not going to do it. Well, I think the advantages of texture based approaches are built-in filtering, memory bandwith and rasterization speed. Disadvantages are, in my opinion, it depends on geometry (bad for large data sets), its not flexible, it doesnt take samples correctly in a perspective view. In the other hand, raycasting is not geometry bound, take the samples correctly in perspective view, but its not suitable for gpu architecture. Regards, Ruben Penalva Hi Binoy,
thanks for sharing your thoughts. I’m thinking about make a texture based glsl volumetric rendering demo, but not now. Just in case, I published a glsl raycasting test recently with source code. Im sorry but I didnt publish the source code for this demo and Im afraid Im not going to do it. Well, I think the advantages of texture based approaches are built-in filtering, memory bandwith and rasterization speed. Disadvantages are, in my opinion, it depends on geometry (bad for large data sets), its not flexible, it doesnt take samples correctly in a perspective view. In the other hand, raycasting is not geometry bound, take the samples correctly in perspective view, but its not suitable for gpu architecture.

Regards,
Ruben Penalva

]]> Comment on Tech Demo: Volume Rendering of a Computed Tomography by Binoy http://www.rpenalva.com/blog/?p=5&cpage=1#comment-3668 Binoy Thu, 01 Apr 2010 04:22:04 +0000 http://www.rpenalva.com/blog/?p=5#comment-3668 Have you thought of a GLSL version of this tech demo? I really liked your interactive way of building the transfer function with full flexibility. Any chance for me to take a look at that part of your implementation? I am working on a similar proxy geometry based(view axis aligned) volume visualization using GLSL Any recommendations or suggestions on the pros and cons with respect to Raycasting Vs Proxy geometry based implementation are welcome and appreciated. Have you thought of a GLSL version of this tech demo?
I really liked your interactive way of building the transfer function with full flexibility.
Any chance for me to take a look at that part of your implementation?
I am working on a similar proxy geometry based(view axis aligned) volume visualization using GLSL
Any recommendations or suggestions on the pros and cons with respect to Raycasting Vs Proxy geometry based implementation are welcome and appreciated.

]]> Comment on Test: CUDA Volume Raycasting 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

]]> Comment on Test: CUDA Volume Raycasting 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

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