#6140 SCI: QFG1VGA - Path finding bug in the forest

closed-fixed
5
2012-10-22
2012-09-17
misterhands
No

Latest daily build Win64
QFG1VGA Eng

In the forest, at the screen with the log near the waterfall (room 81), clicking at the lower right corner (between the tree and the edge of the screen) triggers what appears to be a path finding bug.
Hero seems to understand that he has to go to the south screen, but can't do it directly at the requested coordinates.
So he walks/runs north a bit to the log, but then gets stuck instead of proceeding to the south screen. At this point, Hero stops responding to user input, you have to reload the game.
There is no warning or error msg.

It is impossible to replicate this under DOSBox. In Sierra SCI, Hero always goes right to the waterfall so never attempts to go south from there.
So that might be the root of the problem here.

Discussion

  • misterhands

    misterhands - 2012-09-17
     
  • Filippos Karapetis

    A heads up on this: the issue is that the A* pathfinding code we got adds a penalty score to vertices on the screen edge. The lower right vertex is on the screen edge, thus the pathfinder penalizes it, making ego avoid it and turn around towards the north instead, where he encounters a barrier and stops. Removing the penalty fixes the issue, however it introduces other regressions, where ego follows the wrong path (e.g. in LB2)

     
  • Filippos Karapetis

    • assigned_to: nobody --> thebluegr
    • status: open --> closed-fixed
     
  • Filippos Karapetis

    Fixed with a workaround until a better solution is found in e7d4f88a57efc354cceb34e69acada84600c693d.