Questa tesi ha avuto come principale scopo progettare un framework per l’implementazione di algoritmi di simulazione dinamica su complessi simpli- ciali su Graphical Processing Unit (GPU). La peculiarit´a dell’architettura delle GPU, pensata per velocizzare il processo di visualizzazione, pone molti ostacoli alla realizzazione di algoritmi e strutture dati General Purpose, sia per l’impiego di memoria specializzata, nei formati, nei metodi di allocazione e lettura e nelle dimensioni, per contenere immagini, sia per il paradigma di programmazione offerto. Questi tesi ha dimostrato come, utilizzando i com- plessi simpliciali come struttura di base per la rappresentazione geometrica sia possibile implementare algoritmi computazionalmente pesanti, quali quel- li usati per la modellazione real-time di oggetti deformabili, su GPU. I test sperimentali effettuati hanno dimostrato che l’utilizzo della GPU in questo contesto porta un effettivo guadagno in termini di tempo di calcolo rispetto ad una tradizionale implementazione su CPU.
Appendice A
Screenshot del simulatore
Figura A.1: Deformazione di un cilindro tramite l’applicativo sviluppato parallelamente alla trattazione in esame
APPENDICE A. SCREENSHOT DEL SIMULATORE 136
APPENDICE A. SCREENSHOT DEL SIMULATORE 137
Figura A.3: La rete usata per i test sui 1-complessi simpliciali in due dimensioni
Appendice B
Corrispondenza con la Nvidia
B.1
Bug nel compilatore
---Original Message---
From: Guido Ranzuglia [mailto:inopportuno@yahoo.com] Sent: Wednesday, February 09, 2005 11:35 AM To: GLSL-Support Subject: OGLSL linking -> Exception during compilation [supplement]
sorry the other mail doesn’t contain two little files in the shader directory...
The problematic shader is rungekuttafg.glsl.
euler.glsl is complementary at the rungekuttafg.glsl and can use to test how the application works.
APPENDICE B. CORRISPONDENZA CON LA NVIDIA 139 vtlookup.glsl and fglookup.glsl are the shader that implement the texture’s lookup in the vertex program...
Sorry....
Guido Ranzuglia
_______________________________________________
Hi Guido,
thanks for the report.
Exception messages in the logfile indicate a problem in the compiler and we need to know these to fix them.
I wasn’t really able to find a simple central download location of the VCG on SourceForge, but that was not necessary to reproduce the problem this time. (In the future please submit full projects. You never know if third party code we download from somewhere will be identical to what you tested. There shouldn’t be a problem with bigger attachments as long as they aren’t named .zip)
Nevermind, the good news is that I could reproduce the problem with the 71.80 drivers and the problem does not exist in a newer version I tried.
APPENDICE B. CORRISPONDENZA CON LA NVIDIA 140 That means the problem has been fixed internally and our QA is going to check if the next release already has the fix.
Detlef Roettger
---
Senior Systems Software Engineer Workstation Software Engineering NVIDIA GmbH, Germany
Hi Guido,
no problem, it said this:
>>
we’ve regressed the problem the next imminent driver release does not contain the fix. A driver from the next branch (versions 75+) has the necessary changes.
At this time I don’t know when that driver is going to be publicly available. <<
Sorry that I can’t help more, the problem was in the internal interface between driver and compiler and that was overhauled from release 70 to 75 drivers because of problems like you reported. There is no plan to backport this because rel70 had code freeze.
APPENDICE B. CORRISPONDENZA CON LA NVIDIA 141 Detlef
_____________________________________________
---Original Message---
From: Guido Ranzuglia [mailto:inopportuno@yahoo.com] Sent: Friday, January 14, 2005 5:38 AM To: Keith Galocy Subject: Re: Probably problem with glCopyTexSubImage2D
This is a little visual studio’s project with wich you may be able to reproduce my problem. I have already included it in the bug report but probably it isn’t arrived to you...
Thanks
Guido Ranzuglia
_____________________________________________
B.2
Bug nel driver
Guido,
We have confirmed the issue and cause of the problem. We’ll get it fixed asap.
APPENDICE B. CORRISPONDENZA CON LA NVIDIA 142 Thanks for your assistance, Keith
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