I was wondering if anyone has experienced erroneous overlap reporting using
rtcheck involving BoT solids. We had done some conversions from STL to G,
brought them into the model and did some overlap checking only to find overlaps
where there were clearly no solids colluding. I originally assumed that there
was some bad triangulation that had occurred and we went on a quest to separate
out parts of the STL model and to make sure they were clean and closed volumes.
We then inserted the new STL models into the BRL-CAD model. Same issue. A
coworker said that once he did the separations and reinserted the new parts
into the model that the overlaps went away. He was using 7.24.0. When I opened
the model in 7.26.0 the overlaps were still there. We went to another machine
with 7.24.0 installed, and no overlaps were reported.
What appears to be going on is that the ray is not handling the entrances and
exits correctly and appears to be extruding the BoT solid beyond its actual
bounds causing the overlap. Below is a screenshot of the overlap. The only
objects on the screen were these rollers and their framing. The solids also
appear to look fine on screen when doing an “rt”, but that may be because its
extrusion is into the screen where you wouldn’t see it.
[cid:image001.jpg@01D2456B.61F43FE0]
I even tried the same by replacing the BoT rollers with a temporary on made
from a BRL-AD rcc solid. The overlap remains in 7.26.0. See below.
[cid:image003.jpg@01D2456B.61F43FE0]
Below is the on-screen reporting from the rtcheck run. I see no errors other
than the overlap being reported.
mged> rtcheck -s2048
BRL-CAD Release 7.26.0 RT Check
Mon, 29 Aug 2016 10:39:32 Eastern Daylight Time, Compilation 0
clifford.yapp@ARLAWKLS18400
BRL-CAD Release 7.26.0 The BRL-CAD Ray-Tracing Library
Mon, 29 Aug 2016 10:39:32 Eastern Daylight Time, Compilation 0
clifford.yapp@ARLAWKLS18400
BRL-CAD Release 7.26.0 The BRL-CAD Numerical Computation Library
Mon, 29 Aug 2016 10:39:32 Eastern Daylight Time, Compilation 0
clifford.yapp@ARLAWKLS18400
BRL-CAD Release 7.26.0 The BRL-CAD Utility Library
Mon, 29 Aug 2016 10:39:32 Eastern Daylight Time, Compilation 0
clifford.yapp@ARLAWKLS18400
Compile-time debug symbols are available
Running on 03-HDM1BG2
Planning to run with 8 processors
C:\Program Files\BRLCAD 7.26.0\bin/rtcheck -M -s2048
opendb I:\Active_Projects\008003.001 - DAO - SAC CH-53K MS-C Phase
II\Working\Task 4 - Assessment Refresh\Biggers Work Folder\Brrrrl CAD work
Folder\BoB\Separated\2016-11-22_ch53k.g;
tree cabin_floor_roller_inserts.r temp.s1;
db title: Parts of: Untitled BRL-CAD Database
DIRBUILD: 0.276 user + 0.276 sys in 0.276 elapsed secs (100%)
Additional #malloc=87661, #free=0, #realloc=6 (87661 retained)
000001B70004A040 TOL 5.000000e-004 (sq=2.500000e-007) perp=1.000000e-006,
para=9.999990e-001
Additional #malloc=2050, #free=0, #realloc=1 (2050 retained)
GETTREE: 0.073 user + 0.073 sys in 0.073 elapsed secs (100%)
Additional #malloc=246769, #free=-1, #realloc=2 (246770 retained)
...................Frame 0...................
PREP: 0.043 user + 0.043 sys in 0.043 elapsed secs (100%)
Additional #malloc=25027, #free=0, #realloc=869 (25027 retained)
NUBSP: 0 nu, 6044 cut, 6045 box (0 empty)
Tree: 2 solids in 2 regions
Model: X(5650, 13226), Y(-977, 977), Z(2436, 2480)
View: 55 azimuth, 25 elevation off of front view
Orientation: 0.161569, 0.512432, 0.804357, 0.253613
Eye_pos: 23224.5, 21143.7, 13959.8
Size: 174.365mm
Grid: (0.0851391, 0.0851391) mm, (2048, 2048) pixels
Beam: radius=0.0425695 mm, divergence=0 mm/1mm
OVERLAP PAIRS
------------------------------------------
/cabin_floor_roller_inserts.r and /temp.s1 overlap
</cabin_floor_roller_inserts.r, /temp.s1>: 733 overlaps detected, maximum
depth is 41.5744mm
==========================================
SUMMARY
733 overlaps detected
1 unique overlapping pair (1 ordered pair)
Overlapping objects: /cabin_floor_roller_inserts.r /temp.s1
2 unique overlapping objects detected
SHOT: 9.804 user + 9.804 sys in 10 elapsed secs (98.04%)
Additional #malloc=921, #free=0, #realloc=14 (921 retained)
30941041 solid/ray intersections: 2489059 hits + 28451982 miss
pruned 8.0%: 1014811 model RPP, 1112902830 dups skipped, 1413417 solid RPP
Frame 0: 4194304 pixels in 1.23 sec = 3422524.68 pixels/sec
Frame 0: 3684624 rays in 1.23 sec = 3006629.13 rays/sec (RTFM)
Frame 0: 3684624 rays in 9.80 sec = 375828.64 rays/CPU_sec
Frame 0: 3684624 rays in 10.00 sec = 368462.40 rays/sec (wallclock)
These overlaps do not occur in the previous version of BRL-CAD (7.24.0).
Any thoughts?
Regards,
Robert Anderson
SURVICE Engineering
4141 Colonel Glenn Hwy, Suite 209
Dayton, OH 45431
TEL: (937)431-9914
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