[Navigation 2D] Fix sign of cross product#110815
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Repiteo merged 1 commit intogodotengine:masterfrom Sep 23, 2025
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Regression from splitting the servers. Also replaces the method for getting the triangle area.
AThousandShips
added
bug
regression
topic:navigation
topic:2d
cherrypick:4.5
AThousandShips
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Sep 23, 2025
smix8
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Sep 23, 2025
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Can confirm that this fixes the bug in the 2d corridor funnel path postprocessing. In a few tests I did this now yields the identical paths with all post processing options in both 2d and 3d when using the same navmesh.
(NavigationPolygon.get_navigation_mesh() can be used to convert any 2D navmesh to 3D)
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(Updated the MRP to get around #110807) |
kiroxas
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Sep 23, 2025
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Thanks! |
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Thank you! |
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Cherry-picked to 4.5 |
Repiteo
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cherrypick:4.5
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Regression from splitting the servers. The original code effectively took the cross product using
Vector3(v0.x, 0, v0.y).cross(Vector3(v1.x, 0, v1.y)).y, but this is not equivalent to the 2D cross product which is equivalent toVector3(v0.x, v0.y, 0).cross(v1.x, v1.y, 0).z.The former gives
v1.x * v0.y - v0.x * v1.y, but the latter givesv0.x * v1.y - v1.x * v0.y.Fixed by negating the result in all places, verified against that the original 3D code is the plain cross product.
Also replaced the area formula, using
absinstead which was an oversight in the original code.Added minimal tests for the area formula and also for the closest point method, the latter can be removed if not necessary but wanted to make sure the area formula is correct, verified the area with conventional methods.
Minimal project from smix8 (note that due to #110807 you will need to open the main scene manually, as saving the main scene currently breaks things):
godot-4.5-path-corridorfunnel-bug.zip
Click in the red circle to confirm that the path no longer goes the wrong way
Related (but does not fix the entire issue):