Hello,
I'm doing a Ray Cast of some fairly large volume (examples from http://www.volvis.org) for medical applications.
I'm generating a "DRR", that is, a digital X-Ray of the objects by integrating along a ray.
I have a 1024 by 1024 by 16 bit intensity destination image.
I am rotating about the volume from 0 - 90 or 180 degrees.
I notice, both in my own timings and in the AMD profiler that the read of the 2D projected image is slowing down over time:
For instance
elapsed time = 363.08
elapsed time = 359.41
elapsed time = 353.417
elapsed time = 359
elapsed time = 365.704
elapsed time = 364.322
elapsed time = 364.974
elapsed time = 364.162
elapsed time = 360.681
elapsed time = 358.457
elapsed time = 366.828
elapsed time = 366.772
elapsed time = 369.182
elapsed time = 365.62
elapsed time = 371.733
elapsed time = 373.001
elapsed time = 373.148
elapsed time = 373.764
elapsed time = 376.527
elapsed time = 378.569
elapsed time = 379.176
elapsed time = 380.202
elapsed time = 383.006
elapsed time = 384.96
elapsed time = 385.866
elapsed time = 387.969
elapsed time = 386.392
elapsed time = 386.947
elapsed time = 395.193
elapsed time = 398.699
elapsed time = 400.417
elapsed time = 403.66
elapsed time = 406.639
elapsed time = 410.729
elapsed time = 414.783
elapsed time = 417.085
elapsed time = 420.945
elapsed time = 424.348
elapsed time = 430.082
elapsed time = 434.506
elapsed time = 438.68
elapsed time = 445.329
elapsed time = 441.212
elapsed time = 446.529
And this get's much slower as time goes on.
I don't see any "hints" from the profiler as to what may be the problem. Has anyone seen this type of problem, and what the cause might be?
Thanks,
Rick