View Issue Details

IDProjectCategoryView StatusLast Update
0004911Spring engineGeneralpublic2016-06-09 16:47
Reporterlhog Assigned ToKloot  
PrioritynormalSeveritymajorReproducibilityalways
Status resolvedResolutionfixed 
Product Version100.0 
Summary0004911: pathfinding issues on IsIs Delta, probably on some others
DescriptionConstructor consistently chooses wrong path to approach construction site. Goes in endless loop.
Steps To Reproduce1) Watch the replay
2) Do same
TagsNo tags attached.
Attached Files
20150720_165853_IsisDelta_v02_100.sdf (Attachment missing)
20160216_015957_IsisDelta_v02_100.0.1-1162-gefb8d7epathbug.sdf.gz (Attachment missing)
20160216_192536_IsisDelta_v02_100.0.1-1164-g7e93dd8pathissue.sdf.gz (Attachment missing)
mantis4911.jpg (Attachment missing)
Checked infolog.txt for Errors

Relationships

related to 0005272 resolvedKloot Units can take highly inefficient path 

Activities

hokomoko

2016-02-16 01:00

developer   ~0015792

There are still issues on 100.0+git
I've uploaded a demo

Kloot

2016-02-16 02:13

developer   ~0015794

I assume you mean the issue at 3:20, which is a very old design hack: the set of nodes allowed to be explored is limited by a circular constraint to keep CPU use under control in pathological cases when start and goal are within max-resolution search distance as the crow flies, but separated by half the map in path-space.

Fixing that under the current PFS design will be a bit hairy.

Anonymous

2016-02-16 18:11

viewer   ~0015802

Fix 7e93dd876e5406d5851419139f8b7b14d6136147 committed to develop branch: fix 0004911 (CircularConstraint magically does not need to be active), repo: spring changeset id: 6624

hokomoko

2016-02-16 18:24

developer   ~0015803

Apparently the original issue still exists, attaching a new demo

Kloot

2016-02-16 18:46

developer   ~0015804

Hmm, there seem to be two things going on there:

1) cost flipflopping (very old problem)
2) paths crossing impassable cliffs (news to me, will see if I can find out why)

hokomoko

2016-02-16 18:52

developer   ~0015805

Last edited: 2016-02-16 18:53

can it be that in a lower resolution the node is pathable while in a higher one it isn't?

(due to the cliff being narrow or something)

Kloot

2016-02-16 19:45

developer   ~0015806

Last edited: 2016-02-16 20:15

That fortunately isn't possible (crossing edges have inf-cost) but the problem is more subtle, see screenshot:

start position maps to low-res block <3,2> (markers are block centers)
goal position maps to low-res block <7,3>
low-res path is {<3,2>, <4,2>, <5,3>, <6,3>, <7,3>}

So we get a seemingly valid path, but our goal is on the other side of the cliff running through <7,3> and we need to backtrack. To fix this, goal blocks should be rejected if entered from a direction s.t. a high-res path to the actual goal position does not exist.

e: looks like a relatively easy change, will test for a bit

hokomoko

2016-02-16 22:46

developer   ~0015810

seems to be fixed by https://github.com/spring/spring/commit/7e6b6ee753aa94b7c65930313aa9f176348f345a

Kloot

2016-02-16 23:30

developer   ~0015812

ok, closing since the original "endless loop" condition should now be much rarer and requires a major redesign to tackle fully.

Issue History

Date Modified Username Field Change
2015-07-20 16:06 lhog New Issue
2015-07-20 16:06 lhog File Added: 20150720_165853_IsisDelta_v02_100.sdf
2016-02-16 01:00 hokomoko File Added: 20160216_015957_IsisDelta_v02_100.0.1-1162-gefb8d7epathbug.sdf.gz
2016-02-16 01:00 hokomoko Note Added: 0015792
2016-02-16 02:13 Kloot Note Added: 0015794
2016-02-16 15:22 Kloot Assigned To => Kloot
2016-02-16 15:22 Kloot Status new => assigned
2016-02-16 18:11 Changeset attached => spring develop 7e93dd87
2016-02-16 18:11 Anonymous Note Added: 0015802
2016-02-16 18:11 Anonymous Status assigned => resolved
2016-02-16 18:11 Anonymous Resolution open => fixed
2016-02-16 18:24 hokomoko Note Added: 0015803
2016-02-16 18:24 hokomoko Status resolved => feedback
2016-02-16 18:24 hokomoko Resolution fixed => reopened
2016-02-16 18:24 hokomoko File Added: 20160216_192536_IsisDelta_v02_100.0.1-1164-g7e93dd8pathissue.sdf.gz
2016-02-16 18:46 Kloot Note Added: 0015804
2016-02-16 18:52 hokomoko Note Added: 0015805
2016-02-16 18:52 hokomoko Note Edited: 0015805
2016-02-16 18:53 hokomoko Note Edited: 0015805
2016-02-16 19:45 Kloot Note Added: 0015806
2016-02-16 19:45 Kloot File Added: mantis4911.jpg
2016-02-16 19:47 Kloot Note Edited: 0015806
2016-02-16 20:15 Kloot Note Edited: 0015806
2016-02-16 22:46 hokomoko Note Added: 0015810
2016-02-16 23:30 Kloot Note Added: 0015812
2016-02-16 23:30 Kloot Status feedback => resolved
2016-02-16 23:30 Kloot Resolution reopened => fixed
2016-06-09 16:47 hokomoko Relationship added related to 0005272