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By Design

Votes

0

Found in [Package]

1.1.5

2.0.3

Issue ID

NAVB-126

Regression

No

The generated triangulations ignore the shape of the NavMesh and penetrate the Terrain when generated

Package: AI Navigation

-

How to reproduce:
1. Open the “NavMeshTest“ project
2. Open the “Gym“ scene
3. Open the “NavMesh“ GameObject in the Inspector
4. Bake the NavMesh
5. Under the NavMesh Surface component click on the “Generate Triangles” button
6. Disable the “Model“ GameObject (For visibility)
7. In the Scene view, ensure Show NavMesh is enabled
8. Observe the NavMesh and the generated triangulations of the NavMesh

Expected result: The NavMesh triangulation matches the NavMesh
Actual result: The generated triangulations ignore the shape of some of the “ramps”, penetrate the terrain

Reproducible with: 1.1.5 (2022.3.47f1), 2.0.0 (6000.0.13f1), 2.0.3 (6000.0.20f1)
Could not test with: 1.0.0-exp.4 (2021.3.44f1) (Could not resolve the package issue)

Reproducible on: macOS 14.6.1 (Intel), Windows 10 Pro (22H2)
Not reproducible on: No other environments tested

  1. Resolution Note:

    The behavior is by design and it is described in the manual page of the function NavMesh.CalculateTriangulation()

    https://docs.unity3d.com/ScriptReference/AI.NavMesh.CalculateTriangulation.html

    "The returned mesh contains only the triangles used for pathfinding. It does not contain the detail that is used to place the agents on the walkable surface. This can be noticeable on locations with curved surfaces."

Comments (2)

  1. adriant

    Jan 06, 2025 14:01

    There is currently no way to retrieve the "detail" triangles of the NavMesh data.

    It might be helpful to know that any triangle edge that is a boundary between different area types on the NavMesh belongs to both a "simple" and a "detail" triangle. In other words, creating a difference in area type on the NavMesh brings the "detail" mesh at the same elevation as the "simple" mesh on that boundary edge, and thus keeps the two representations closer together near that edge.

  2. logan4179

    Dec 18, 2024 19:26

    Is there a way to get this data?

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